Phospholipid
Phosphatidylserine
Moderate EvidenceSupported by trials in age-associated memory impairment, and it carries an FDA qualified health claim - which is explicitly a claim backed by limited and inconclusive evidence, not an endorsement. The trials split by source. Bovine-cortex PS at 100 mg three times daily for 12 weeks improved learning and memory tasks against placebo in 149 adults with age-associated memory impairment, mostly in those who started lowest (Crook 1991), and 300 mg a day for six months improved behaviour and memory scores in 494 adults aged 65–93 with moderate-to-severe cognitive decline (Cenacchi 1993). The soy-derived PS you can actually buy has not repeated that cleanly: in 120 adults over 57 with memory complaints, 300 or 600 mg a day for 12 weeks changed no outcome at all (Jorissen 2001), and in 78 Japanese adults aged 50–69, 100 or 300 mg a day for six months improved delayed recall only in those with low starting scores (Kato-Kataoka 2010). For stress, the positive results used either a PA+PS complex at 400 mg (Hellhammer 2004) or 600 mg of PS before exercise in ten men (Starks 2008). Compared with citicoline, which has a positive 12-week trial in healthy older adults with memory complaints, and bacopa, which has a meta-analysis, PS has the weaker case for the product on the shelf; it pairs logically with omega-3 but neither substitutes for the other. Verdict: a low-risk option for older adults with memory complaints who start low, at 100–300 mg a day for three to six months — with modest expectations, and not a cortisol dose at 100 mg.
Recommended Dose
100–300 mg daily
Timing
Morning or evening with food
Mechanism of Action
Phosphatidylserine (PS) is a phospholipid the brain needs for healthy nerve-cell membranes and myelin (Glade 2015). Major component of neuronal cell membranes; it is thought to modulate membrane fluidity and neurotransmitter release. Its cortisol effect is dose- and form-specific: a phosphatidic-acid-plus-PS complex blunted the hormonal response to a laboratory stress test at 400 mg but not at higher doses (Hellhammer 2004). Source matters for the evidence: the early positive memory trials used PS extracted from bovine brain cortex (BC-PS), while products sold today are made from soy or sunflower lecithin — soy PS is produced from soybean lecithin by an enzymatic reaction with L-serine (Kato-Kataoka 2010).
Side Effects & Safety
Very well-tolerated. Rare insomnia or GI discomfort at higher doses. Modern PS is soy or sunflower-derived (not bovine).
Do not use / talk to a doctor first
- Known allergy to the source material - modern products are soy or sunflower derived, which matters if you have a soy allergy
Interactions
Anticoagulants and antiplatelet drugs
Frequently listed as a bleeding interaction, and the evidence does not support that for oral supplements. The anticoagulant finding comes from a 1981 study of INTRAVENOUS phosphatidylserine, and in other contexts phosphatidylserine ACCELERATES coagulation. Neither describes taking a capsule. Treat this as unestablished in both directions rather than as a warning or an all-clear
Source: Tersenov 1981, Vopr Med Khim (PMID 7314577)
Pregnancy & breastfeeding
Not adequately studied in pregnancy or breastfeeding. Not recommended without medical advice.
Who should avoid / see a doctor
Anyone with a soy allergy should check the source, since most products are soy-derived. Beyond that there is no established contraindication for oral phosphatidylserine, and the bleeding warning that circulates alongside it rests on intravenous and in-vitro work rather than on supplement use.
Synergies
Used in These Stacks
See Phosphatidylserine inside a full protocol — the stack pages cover when and why to combine it.
Best Products
Partner offers
Paid placements. We earn a commission if you buy through these links, at no extra cost to you — it does not change what we write. These are the seller’s own products and claims, not ours, and nothing here is medical advice. Speak to a clinician before starting any supplement.
References
- 1.Tersenov 1981, Voprosy Meditsinskoi Khimii — Intravenous phosphatidylserine produced a dose-dependent decrease in blood coagulation activity - an intravenous finding, not a study of oral supplementation. (intravenous administration, 1981)
- 2.Crook 1991, Neurology — 149 patients with age-associated memory impairment, 12 weeks of bovine-cortex PS (BC-PS) 100 mg three times daily or placebo: improvement on performance tests of learning and memory tasks of daily life, most likely in those performing at a relatively low level before treatment. (bovine-derived PS, no longer the form on sale)
- 3.Cenacchi 1993, Aging (Milano) — 494 elderly patients (65–93) with moderate to severe cognitive decline, 23 Italian centres, double-blind: BC-PS 300 mg/day for 6 months improved behavioural and cognitive scores versus placebo; well tolerated. (bovine-derived PS)
- 4.Jorissen 2001, Nutr Neurosci — 120 adults over 57 meeting criteria for age-associated memory impairment, randomised to placebo, 300 mg or 600 mg soy-derived PS daily for 12 weeks: no significant differences in any outcome, including delayed recall and recognition. (null result for soy PS)
- 5.Kato-Kataoka 2010, J Clin Biochem Nutr — 78 Japanese adults aged 50–69 with memory complaints, soy PS 100 or 300 mg/day or placebo for 6 months: scores rose in all groups including placebo; in those with low baseline scores, memory (mainly delayed verbal recall) improved on PS; no side effects.
- 6.Hellhammer 2004, Stress — Four groups of 20 took 400, 600 or 800 mg/day of a soy phosphatidic acid + PS complex or placebo for 3 weeks: 400 mg blunted ACTH and cortisol responses to the Trier Social Stress Test; higher doses did not.
- 7.Starks 2008, J Int Soc Sports Nutr — 10 healthy men, double-blind crossover: 600 mg PS/day for 10 days lowered peak cortisol and cortisol area-under-curve after moderate-intensity cycling versus placebo.
- 8.Glade 2015, Nutrition — Review of 127 articles: PS is required for healthy nerve-cell membranes and myelin; the authors conclude oral PS at 300–800 mg/day is absorbed and supports a wide range of cognitive functions. (narrative review whose conclusions are far more confident than the soy-PS trials above)
