This page shows what was measured, who it was measured in, and what that does not settle.
What Sibutramine does in the body
Sibutramine stops both from being cleared away, so the fullness signal stays switched on longer and people eat less.
Nerve cells in the part of the brain that judges fullness use two chemical messengers. The same messengers also drive the sympathetic nervous system, so the heart beats faster and blood pressure rises a little. Over three and a half years in people who already had heart disease, that second effect cost more than the weight loss saved.
Why people take it. A prescription appetite suppressant for obesity
What happened in people
Diastolic blood pressure up 2.3 mm Hg and pulse up 4.1 beats per minute over two years
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The recorded finding that sits closest to something a person would notice. Written into the record, not signed off, and it carries no population or interval.
That weight loss and improved lipid and glycaemic surrogates would translate into fewer cardiovascular events
Where it acts
Hypothalamic satiety centres; also peripheral sympathetic nerve terminals
Kind of result
A number that stands in for health
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
What the registries record it as
Its recorded molecular formula is C17H26ClN, weighing 279.8.
PubChem record · 5210 · read 2026-08-29
Where each sentence above came from
A person wrote this explanation into the record, with the studies named in the path below.
The recorded use, written for a reader without medical training. Not signed off.
A limit recorded against this substance. Not signed off as a reviewed claim.
The four opening statements run to 102 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Stand-in result
A stand-in result is a number measured because the real result takes too long.
A picture of it, and where the picture fails
It is like judging a journey by the speedometer rather than by arriving.
Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.
What people get wrong. A stand-in result is often reported as the result itself.
A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Absolute difference
An absolute difference is how many more people in a hundred were affected.
A picture of it, and where the picture fails
It is like counting heads in two rooms of a hundred.
Where that stops being true. Heads are easy to count. Study results carry a margin of error too.
What people get wrong. It is confused with a percentage change, which can look far larger.
The arithmetic difference in event rates between arms.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 15 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Body weight
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
△Only a number moved7 registered test measure.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
Body weight
post cessation weight change; weight loss; body weight from baseline to week 12; body weight loss; body weight from baseline to 24 week endpoint; fat mass; visceral fat mass improvement
Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.
What each mark on this table means
∅ Nothing in the sources checked
No registered study lists a life outcome for this goal.
△ Only a number moved
7 registered test measure.
— Not recorded
Harms were not a registered measure for this goal.
… Waiting for a reviewer
Who was studied is listed further down the page.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Proportion of patients at year 2 maintaining at least 80% of the weight lost between baseline and month 6
✓ The study showed what it set out to show
Who was studied
STORM (Sibutramine Trial of Obesity Reduction and Maintenance)
How many people
467
Study design
Phase 3 randomised withdrawal trial
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Odds ratio 4.64, P < 0.001 (43% versus 16% of completers)
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Twenty patients (3%) were withdrawn for rising blood pressure; diastolic pressure rose 2.3 mm Hg and pulse 4.1 beats per minute over two years. Dropout reached 42% on drug and 50% on placebo, so the headline maintenance figures describe completers.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral capsule, once daily (5, 10 and 15 mg)
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Time to first nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, or cardiovascular death over a mean 3.4 years
✗ The study did not show it
Who was studied
SCOUT (NCT00234832)
How many people
9804
Study design
Phase 4 cardiovascular outcomes trial
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Hazard ratio 1.16 (95% CI 1.03 to 1.31), P = 0.02, against sibutramine
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. All 10,744 enrolled subjects received open-label sibutramine during the six-week lead-in before randomisation, which removed from the randomised comparison anyone who reacted badly early.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral capsule, once daily (5, 10 and 15 mg)
Interval reported. 95% CI 1
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 2 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
□Living longer, or avoiding a major eventNo evidence recorded. Death, a heart attack, a stroke, a hospital stay.0 registered measures of this kind. 1 written-up study measured this and did not show a benefit.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
□Symptoms and quality of lifeNo evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.No registered study measures this.
■A number that stands in for healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.11 registered measures of this kind.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
□AnimalsNo evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.No animal record is stored.
□Cells in a dishNo evidence recorded. Cells or chemistry on a bench, far from a whole body.No cell or bench record is stored.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Sibutramine
What a person takes: Oral capsule, once daily (5, 10 and 15 mg).
The measurement behind this step
Once-daily oral capsule taken as an adjunct to a reduced-calorie diet. The parent compound is a prodrug converted by CYP3A4 to two longer-lived active metabolites, so the effective exposure outlasts the parent by a wide margin and interacts with CYP3A4 inhibitors.
Getting in
Swallowed once daily and converted into its active forms
The capsule itself does little. The liver turns it into two related molecules that do the work.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Sibutramine is a prodrug. First-pass CYP3A4 metabolism yields the mono-desmethyl (M1) and di-desmethyl (M2) metabolites, which are substantially more potent reuptake inhibitors than the parent and have longer half-lives.
The active molecules cross into the brain and reach the region that decides when you have eaten enough.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
M1 and M2 distribute into the central nervous system and act at nerve terminals in hypothalamic nuclei that regulate energy intake, alongside peripheral sympathetic terminals.
Blocks the noradrenaline and serotonin transporters
They plug the two pumps that clear these messengers away, so both stay in the gap between nerve cells for longer.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Inhibition of SLC6A2 (norepinephrine transporter) and SLC6A4 (serotonin transporter), with weaker inhibition of SLC6A3 (dopamine transporter). Unlike the fenfluramines, sibutramine does not act as a releasing agent — it blocks reuptake only, which is why it does not carry their valvular signal.
Meals end sooner. At the same time the heart beats faster and blood pressure sits slightly higher, because the same messengers drive both.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Enhanced satiety signalling reduces energy intake; there is also evidence of a small thermogenic contribution. The identical noradrenergic mechanism raises resting heart rate and diastolic blood pressure, measured in STORM at 4.1 beats per minute and 2.3 mm Hg over two years.
Weight falls; nonfatal myocardial infarction and stroke rise
Both outcomes were measured in the same trial. The weight difference was 1.7 kilograms. The excess in heart attacks and strokes was 1.4 percentage points.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Measured endpoints: post-randomisation weight difference 1.7 kg, primary composite cardiovascular event 11.4% versus 10.0% (HR 1.16, 95% CI 1.03 to 1.31), nonfatal MI HR 1.28, nonfatal stroke HR 1.36, no increase in cardiovascular or all-cause mortality.
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 5 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
No registered study measured anything of this kind.
Measured
Things only a test, a scale or a device shows.
post cessation weight change
weight loss
body weight from baseline to week 12
body weight loss
systolic blood pressure
diastolic blood pressure
body weight from baseline to 24 week endpoint
waist circumference
blood pressure
fat mass
and 1 more.
Meaningful
Things that change how a life goes, not only a number.
No registered study measured anything of this kind.
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
Names that fit none of the three (4)
smoking cessation
weight
safety parameters
anti mullerian hormone levels
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Nobody now. Between 1997 and 2010 it was the most widely used prescription weight-loss drug in much of the world after the fen-phen withdrawal removed the alternatives.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
Where the result stopped carrying
SCOUT missed its primary endpoint in the wrong direction: more nonfatal myocardial infarctions and strokes on the drug
European marketing authorisations suspended 6 August 2010; United States withdrawal 8 October 2010
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Withdrawn
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral capsule, once daily (5, 10 and 15 mg)
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S8.
No source is stored against this line.
What is in the pack
Once-daily oral capsule taken as an adjunct to a reduced-calorie diet. The parent compound is a prodrug converted by CYP3A4 to two longer-lived active metabolites, so the effective exposure outlasts the parent by a wide margin and interacts with CYP3A4 inhibitors.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
Withdrawn worldwide in 2010 for excess nonfatal myocardial infarction and stroke. The measured harms are a hazard ratio of 1.16 for the composite cardiovascular endpoint, 1.28 for nonfatal MI and 1.36 for nonfatal stroke, over a mean 3.4 years, with no excess of cardiovascular or all-cause death. Dose-related increases in pulse and blood pressure are consistent findings, and the drug was contraindicated with monoamine oxidase inhibitors and other serotonergic agents.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear∅Nothing found in the sources checked
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral capsule, once daily (5, 10 and 15 mg)
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
The parent compound is a prodrug converted by CYP3A4 to two longer-lived active metabolites, so the effective exposure outlasts the parent by a wide margin and interacts with CYP3A4 inhibitors.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
Self-experiment planning is not offered for a prescription or clinician-supervised medicine, withdrawn medicine. The questions below are for a clinician or pharmacist.
Questions worth asking
Which of the trials of Sibutramine studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That weight loss and improved lipid and glycaemic surrogates would translate into fewer cardiovascular events
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the small mean rises in pulse and diastolic pressure recorded from 2000 onwards were clinically negligible in a population selected for cardiovascular risk
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
How fast does the body clear it?
The sources RNAWiki checked hold nothing for this field.
Why it matters. Without this, nothing on this page can say how long anything lasts.
What would answer it
A stored source that records it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Sibutramine are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
STORM: weight loss was maintained for two years, with an odds ratio of 4.6
In plain words
Of the people who finished a two-year trial, 43% on sibutramine kept off at least four fifths of the weight they had lost, against 16% on placebo. The drug worked at the thing it was licensed for.
What was measured
Proportion maintaining at least 80% of six-month weight loss at two years
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Eight European centres recruited 605 obese patients (BMI 30 to 45 kg/m2) for six months of open sibutramine 10 mg daily plus an individualised 600 kcal/day deficit programme. The 467 patients (77%) who lost more than 5% were then randomised double-blind to sibutramine (n=352) or placebo (n=115) for a further 18 months. Of trial completers, 89 of 204 (43%) on sibutramine maintained 80% or more of their original weight loss against 9 of 57 (16%) on placebo (odds ratio 4.64, p<0.001). Dropout was 42% and 50% respectively. HDL cholesterol rose 20.7% against 11.7% (p<0.001).
Written into the record, not signed off as a reviewed claim
The blood pressure and pulse signal was visible in STORM in 2000
In plain words
The same two-year trial recorded that diastolic blood pressure and pulse rose on the drug, and that 3% of patients had to be withdrawn because their blood pressure went up. It was published a decade before the withdrawal.
What was measured
Change in diastolic blood pressure and pulse rate over two years
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In STORM, 20 patients (3%) were withdrawn because of increases in blood pressure. In the sibutramine group, from baseline to two years, systolic blood pressure rose by 0.1 mm Hg (SD 12.9), diastolic by 2.3 mm Hg (SD 9.4), and pulse rate by 4.1 beats per minute (SD 11.9). These are small mean shifts in a population already at elevated cardiovascular risk, and they are the pharmacological fingerprint of noradrenaline reuptake blockade rather than an idiosyncratic reaction.
Written into the record, not signed off as a reviewed claim
SCOUT: 11.4% versus 10.0% major cardiovascular events, hazard ratio 1.16
In plain words
The one trial that measured heart attacks and strokes rather than kilograms found more of them on the drug. It enrolled nearly ten thousand people and ran three and a half years.
What was measured
Time to first nonfatal MI, nonfatal stroke, resuscitated cardiac arrest or cardiovascular death
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
SCOUT (NCT00234832) enrolled 10,744 overweight or obese subjects aged 55 or older with pre-existing cardiovascular disease, type 2 diabetes, or both. All received sibutramine during a six-week single-blind lead-in; 9,804 were then randomised double-blind to sibutramine (n=4,906) or placebo (n=4,898). Mean treatment duration 3.4 years. The primary composite — nonfatal myocardial infarction, nonfatal stroke, resuscitated cardiac arrest, or cardiovascular death — occurred in 11.4% on sibutramine against 10.0% on placebo (HR 1.16, 95% CI 1.03 to 1.31, p=0.02). Nonfatal myocardial infarction 4.1% versus 3.2% (HR 1.28, 1.04 to 1.57, p=0.02); nonfatal stroke 2.6% versus 1.9% (HR 1.36, 1.04 to 1.77, p=0.03). Cardiovascular death and all-cause death were not increased.
Written into the record, not signed off as a reviewed claim
The weight advantage after randomisation was 1.7 kg
In plain words
After everyone had already lost weight in the run-in, the extra weight loss the drug delivered over three and a half years averaged 1.7 kilograms. That is the benefit side of the trade the trial priced.
What was measured
Mean post-randomisation weight difference and blood pressure difference
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In SCOUT, mean weight loss during the six-week lead-in, when everyone received sibutramine, was 2.6 kg. After randomisation the sibutramine group achieved and maintained a further mean reduction of 1.7 kg relative to placebo. Mean blood pressure fell in both groups but less on sibutramine, a mean difference of 1.2/1.4 mm Hg favouring placebo. The trial therefore put a number on both sides of the mechanism at once: modest sustained weight loss, and a modest sustained blood pressure penalty, in the same 9,804 people.
Written into the record, not signed off as a reviewed claim
Regulators reversed within nine months of the SCOUT data
In plain words
Europe suspended the drug in August 2010 and the FDA asked the manufacturer to pull it in October 2010. The trial that triggered it had been requested by regulators as a condition of keeping the drug on sale.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The SCOUT data safety monitoring board reported in October 2009 that sibutramine was associated with more cardiovascular problems than placebo. Germany requested a European review in November 2009; the CHMP opinion followed on 21 January 2010, concluding that the benefits of sibutramine did not outweigh its risks and that all European marketing authorisations should be suspended. The European Commission suspension took effect on 6 August 2010. On 8 October 2010 the FDA issued a Drug Safety Communication recommending against continued prescribing and use, and Abbott agreed to voluntary withdrawal. Drugs@FDA now records NDA 020632 (MERIDIA, Abbott) as Discontinued.
Source
EMA sibutramine Article 107 referral outcome, 2010; FDA Drug Safety Communication, 8 October 2010
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Weight loss was assumed to buy cardiovascular benefit. It was never tested until SCOUT
In plain words
The whole case for the drug rested on the idea that losing weight protects the heart, so a drug that causes weight loss must protect the heart. Nobody checked for thirteen years, and when they did the answer was the opposite.
What was measured
That drug-induced weight loss and improved metabolic surrogates would produce fewer cardiovascular events, when the same drug also raised heart rate and blood pressure
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Sibutramine was approved in 1997 on weight and metabolic surrogate endpoints: kilograms, waist circumference, triglycerides, HDL cholesterol, glycaemic indices. Every one of those moved in the favourable direction and STORM confirmed they stayed moved. The inference that this would translate into fewer cardiovascular events treats the surrogate as though it carried the whole causal chain, and ignores that the same molecule was simultaneously raising pulse and diastolic pressure. SCOUT measured the endpoint directly and found a 16% relative increase in the composite. The surrogates were not wrong about weight; they were the wrong quantity to be measuring.
Written into the record, not signed off as a reviewed claim
It did not disappear — it became one of the commonest supplement adulterants
In plain words
Sibutramine is repeatedly found in products sold as herbal slimming teas and capsules, undeclared on the label. The analytical literature on finding it in those products is now larger than the clinical literature.
What was measured
Detection of undeclared sibutramine in marketed slimming products
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Sibutramine appears consistently in surveillance of undeclared pharmaceutical adulterants in slimming supplements. Published detection work includes validated LC-ESI-MS/MS with polarity switching for synthetic adulterants in natural and herbal slimming products, and rapid HPLC-ESI-MS methods for simultaneous analysis of fifteen key chemicals in slimming foods and herbal products. The FDA maintains a public list of tainted weight-loss products in which sibutramine is among the most frequently named undeclared ingredients. This matters clinically because the people buying an "herbal" product are not being monitored for the blood pressure and pulse effects that ended the licensed drug.
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What is not here
4 questions this page could not answer
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What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
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The record as stored
The full record, for auditing
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The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
A serotonin-noradrenaline reuptake inhibitor that reliably produced and maintained modest weight loss, and in the only trial that ever measured hard cardiovascular outcomes produced a 16% excess of major events in 9,804 randomised patients.
Recorded evidence blocks (8)
Q2
What did Sibutramine's largest trial (10777 people) and its longest (8.9 years) measure?
10777 people in Sibutramine's largest registered study, 8.9 years in its longest registered window, measuring Post-cessation weight change. ClinicalTrials.gov · 2026-09-01
10 phase3, 8 phase4, 5 phase2, 4 na, 2 phase1; NCT01475019; 2012-12; no ageing endpoint recorded. Last human test completed 2012, NCT00537810.
Interpretation These counts include studies where Sibutramine was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
Show the evidence
phase3
10
phase4
8
phase2
5
na
4
phase1
2
Last recorded human testNCT00537810
2012-10
recorded 2026-09-01 · last checked 2026-09-04
Q3
Sibutramine was tested only in human — what did it show?
4 recorded entries; human; also "ADF1 Group Eurofarma drug association of Sibutramine IR 15mg / Topiramate XR 75mg", "ADF2 Group Eurofarma drug association of Sibutramine IR 15mg / Topiramate XR 100mg", "SIB Group Sibus (Sibutramine) 15mg"
Show the evidence
human
NCT05209984
ADF1 Group Eurofarma drug association of Sibutramine IR 15mg / Topiramate XR 75mg
NCT05209984
ADF2 Group Eurofarma drug association of Sibutramine IR 15mg / Topiramate XR 100mg
NCT05209984
SIB Group Sibus (Sibutramine) 15mg
NCT05209984
Sibutramine 15mg
recorded 2026-09-01 · last checked 2026-09-04
Q6
Which of anti mullerian hormone levels, blood pressure and body weight from baseline to 24 week endpoint did Sibutramine's trials measure?
anti mullerian hormone levels, blood pressure and body weight from baseline to 24 week endpoint lead 15 outcome terms across Sibutramine's trials. ClinicalTrials.gov · 2026-09-01
weight loss, safety parameters, body weight from baseline to week 12, body weight loss, systolic blood pressure and diastolic blood pressure follow.
Show the evidence
post cessation weight change
1
smoking cessation
1
weight
1
weight loss
1
safety parameters
1
body weight from baseline to week 12
1
9 more recorded rows
body weight loss
1
systolic blood pressure
1
diastolic blood pressure
1
body weight from baseline to 24 week endpoint
1
waist circumference
1
blood pressure
1
fat mass
1
visceral fat mass improvement
1
anti mullerian hormone levels
1
recorded 2026-09-01 · last checked 2026-09-04
Q7
Which 15 trials of Sibutramine posted no result?
Posted no result
15 of 15 completed trials
Registrations
NCT00261911, NCT00044187, NCT00134199, NCT00330525, NCT00463112 and NCT00165685, and 9 more
Completion dates
oldest 2002-02; newest 2010-07
Show the evidence
Trial
NCT00261911
2002-02
NCT00044187
2003-09
NCT00134199
2005-11
NCT00330525
2006-03
NCT00463112
2006-09
NCT00165685
2007-03
9 further recorded trials
NCT00212173
2007-08
NCT00402077
2007-08
NCT00729963
2007-09
NCT00433641
2007-11
NCT00037752
2008-08
NCT00537420
2008-09
NCT00914212
2009-08
NCT01597609
2010-03-04
NCT01184560
2010-07
Q8
At the median, Sibutramine's trials enrolled 130 people — anything larger?
Median enrolment
130
Largest enrolment
10777
Registered trials counted
27
Q9
Was Sibutramine studied with caloric restriction and exercise?
caloric restriction and exercise are named in Sibutramine's label sentences: "To achieve moderate calorie restriction (deficit > or = 250-500 kcal/day), individual dietary counselling was accompanied by either placebo or sibutramine (initial dosage of 5 mg/day titrated up by 5 mg biweekly through week 6, and maintained at 20 mg through week 24)." openfda-label+europepmc · 2017-07-01
2 recorded statements; caloric restriction, exercise
Show the evidence
caloric restriction
To achieve moderate calorie restriction (deficit > or = 250-500 kcal/day), individual dietary counselling was accompanied by either placebo or sibutramine (initial dosage of 5 mg/day titrated up by 5 mg biweekly through week 6, and maintained at 20 mg through week 24).
exercise
In total, 8192 obese patients with diabetes were randomized to sibutramine or placebo plus diet and exercise after a preliminary 6 weeks in which all patients received sibutramine.
recorded 2017-07-01 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 8 source rows
✓ no critical contamination: no quarantine open
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✓ no raw internal fields: enforced by the copy-contract test over the rendered page
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