Phosphatidylserine (PS)

Evidence: ★★★☆☆ · Status: OTC Supplement

In plain English

A building block of brain-cell membranes. Older studies (using cow-brain PS) improved memory in ageing; the soy-derived PS sold today has weaker, mixed cognitive data but may blunt stress-cortisol spikes.

How it works

A phospholipid concentrated in neuronal cell membranes; supports membrane fluidity, receptor function and neurotransmitter release, and appears to dampen the HPA-axis cortisol response to acute stress.

Molecular target & official sources

Phosphatidylserine (PubChem CID 9547096) — a structural membrane phospholipid (no single receptor).

Protocol

100–300 mg/day.

Bottom line

Reasonable for age-related memory and for cortisol/stress; don't expect a big effect from modern soy-PS on a healthy young brain.

Helps with: Focus & Cognition · Cardiovascular · Stress & Anxiety

The human evidence

Early trials with bovine-derived PS showed memory benefit in age-related cognitive decline; soy-derived PS (the current form) shows weaker, inconsistent cognitive results. Several small studies suggest it reduces the cortisol response to acute stress and exercise. Well tolerated.

Stacks with

Omega-3 (DHA), Acetyl-L-carnitine.

Shares a pathway — often paired with: Magnesium, Phentermine / Qsymia (phentermine-topiramate), Ashwagandha (Withania somnifera), Vitamin C (Ascorbate).

Availability & where to buy

Available over the counter. Widely available OTC — e.g. iHerb (ships worldwide); in Singapore also Guardian, Watsons, GNC, Shopee / Lazada. Look for a third-party-tested / GMP mark and check the dose per serving. Moderate (~S$25–40/month).

How it works: the HPA axis pathway →