Full profile
| Also known as | PS |
|---|---|
| Best for | Memory support · Cognitive load and stress |
| Evidence grade | Grade C · Limited: early or small human trials |
| Studied dose range | 100 mg two to three times daily (≈200–300 mg total) in most studies; Jorissen tested up to 600 mg daily. |
| Time to effect | Often studied over several weeks of daily use. |
| Best form | Soy- or sunflower-derived PS with a stated milligram dose. |
Evidence, honestly graded
This is a wrong-source, wrong-population discount. The classic positive trials (Crook 1991, bovine-cortex PS; Kato-Kataoka 2010, soy-PS with a positive result only in a low-baseline subgroup) don't match what a modern label delivers to a healthy adult: a direct RCT of soy-derived PS at both 300 mg and 600 mg/day (Jorissen et al. 2001) failed to beat placebo on the primary cognitive measures in the target population. The FDA's own qualified health claim review for PS and cognitive function/dementia concluded there is "little scientific evidence" supporting the claim. Still a reasonable, well-tolerated inclusion, but the honest grade for soy/sunflower PS in a healthy adult is C, not B.
See the full grading rubric (study type, replication, population match, and dose adequacy) in The Evidence Standard.
What the benefits research does and doesn't support, in depth: Phosphatidylserine Benefits: Sorting the Evidence from the Marketing.
434 natural health products with an active licence in Health Canada's LNHPD list Phosphatidylserine as a medicinal ingredient.
That makes Phosphatidylserine a recognized, licensable medicinal ingredient in Canada, regulated by Health Canada's Natural and Non-prescription Health Products Directorate, which issues each licensed natural health product a Natural Product Number (NPN). Search the LNHPD to verify.
Side effects
- Generally well tolerated
- Occasional GI upset or insomnia at higher doses
Who should avoid it or check first
- On blood-thinning medication without clinician review
- Pregnant or breastfeeding without guidance
Interactions
- May interact with blood thinners and anticholinergic medications; discuss with a clinician
Stacks well with
What to look for on a label
- Check the elemental PS dose per serving.
- Sunflower-derived PS is an option for those avoiding soy.
References
- Kato-Kataoka A, Sakai M, Ebina R, et al. (2010). Journal of Clinical Biochemistry and Nutrition, 47(3):246–255Delayed verbal recall improved versus placebo in a low-baseline subgroup.
- Crook TH, Tinklenberg J, Yesavage J, et al. (1991). Neurology, 41(5):644–649Improved name-face and daily-task memory measures versus placebo.
- Jorissen BL, Brouns F, Van Boxtel MP, et al. (2001). Nutritional Neuroscience, 4(2):121–134No significant improvement over placebo on the primary cognitive measures at either dose.
- FDA qualified health claim decision: phosphatidylserine and cognitive function/dementia. FDA's own review of the evidence for a PS/cognition qualified health claim concluded there is "little scientific evidence" supporting it. That is the basis for grading soy/sunflower PS conservatively rather than trading on the older bovine-PS trials.
Entries above without a linked identifier are either editorial summaries of a wider body of literature or references to a named authority (a regulator or government monograph) cited by name rather than by a single paper.
Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.
Revision history
Every change to this ingredient's evidence status, dated and explained. The full cross-library log lives at Evidence Updates.
- 2026-07-07Grade changeGrade B → Grade C
Downgraded from B to C. The stronger data sit in age-related decline and soy-derived PS trials; the healthy-adult, focus-specific evidence at label-realistic doses is thinner than a B implies.
See how Phosphatidylserine compares on grade, dose, and goal in the Evidence Explorer.