Phentermine / Qsymia (phentermine-topiramate)

Evidence: ★★★★☆ · Status: FDA Approved, Controlled

In plain English

Turns down appetite through the adrenaline system. Phentermine alone is short-term; the Qsymia combo works longer. Pre-GLP-1 mainstays.

How it works

Phentermine is a norepinephrine-releasing appetite suppressant (amphetamine relative, Schedule IV). Topiramate adds appetite suppression via GABA modulation and carbonic-anhydrase inhibition.

Molecular target & official sources

Phentermine (PubChem CID 4771) · SLC6A2 norepinephrine transporter (NCBI Gene)

Bottom line

Effective, older prescription options now second-line to GLP-1s.

Helps with: Lose Fat

Stacks with

Shares a pathway — often paired with: Caffeine, Semaglutide (Ozempic / Wegovy / Rybelsus), Tirzepatide (Mounjaro / Zepbound), Modafinil / Armodafinil.

Availability & where to buy

Controlled substance. A controlled substance in most countries — illegal to buy, sell or possess without authorisation (in Singapore: HSA / CNB). Education only.

How it works: the GPCR → cAMP pathway →