Rankings / Cognitive

Phosphatidylserine

Cognitive · Membrane phospholipid

Tier B+

Reviewed by Read Off Label · Last reviewed · How we grade

otc
7.1 / 10
Tier B+
Ev 6 Bn 5 Sf 9

Bottom line

Read Off Label grades Phosphatidylserine as B+ (7.1/10) based on moderate evidence, med benefit magnitude, and a low-risk safety profile.

Originally from bovine brain (prion concerns retired that source); current products from soy or sunflower lecithin.

Studied, labeled, or reported-use context: 100-300 mg/day PO — OTC; not individualized guidance.

What the evidence says

Originally from bovine brain (prion concerns retired that source); current products from soy or sunflower lecithin. Starks 2008 showed reduced cortisol response to physical stress. Small studies report outcomes in age-related cognitive complaints; evidence is rated Moderate in this entry. Two 2026 randomized trials, reviewed 2026-08-29. The more interesting one is **vascular, not cognitive**: a double-blind placebo-controlled trial in adults with type 2 diabetes (900 mg/day for 4 weeks, delivering ~280 mg/day PS) improved leg blood flow response to an oral glucose load and reduced load-dependent aortic pulse wave velocity, alongside mechanistic work showing PS binds and inhibits ADAM17 — the enzyme that sheds endothelial insulin receptors. That is a genuinely new mechanism and indication for a supplement sold almost entirely on cognition, though it is one trial in a disease population and says nothing about healthy adults. The second, in 97 professional footballers (randomized, triple-masked, 14 days), found effects on Stroop and visual reaction time, perceived mental fatigue and 30 m sprint — but **PS was given combined with 1,500 mg taurine and 200 mg caffeine**, and while the design includes a taurine+caffeine-only arm to isolate PS, caffeine alone plausibly accounts for much of a reaction-time effect. Neither moves this row's rating; the vascular finding is the one worth watching.

Mechanism

Major acidic phospholipid in neuronal membranes; supports membrane fluidity, receptor density, neurotransmitter release; blunts cortisol response to stress

Studied, labeled, or reported dose & route

100-300 mg/day PO

This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.

Citations

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Common questions

What does the evidence show about Phosphatidylserine's effects?
Read Off Label rates the evidence for Phosphatidylserine as Moderate and the benefit magnitude as med, producing an overall grade of B+ (7.1/10). Originally from bovine brain (prion concerns retired that source); current products from soy or sunflower lecithin.
What safety findings are reported for Phosphatidylserine?
Phosphatidylserine has a low risk profile in the database. Low (GI upset) Legal status: OTC.
What doses or routes are reported for Phosphatidylserine?
100-300 mg/day PO This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
How does Phosphatidylserine work?
Major acidic phospholipid in neuronal membranes; supports membrane fluidity, receptor density, neurotransmitter release; blunts cortisol response to stress

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.