Phosphatidylserine

The best-known positive data come from bovine-cortex PS: Crook et al. treated 149 people with age-associated memory impairment (AAMI) with 300 mg/day for 12 weeks and saw improvement on learning and daily-memory tasks, concentrated in those who started out most impaired ^{1Reference 1Crook et al. · 1991RCTEffects of phosphatidylserine in age-associated memory impairment — [RCT]View study →}.

Cenacchi et al. ran a larger 6-month multicenter trial in 494 elderly patients (300 mg/day) and reported benefit on behavioral and cognitive measures ^{2Reference 2Cenacchi et al. · 1993RCTCognitive decline in the elderly: a double-blind, placebo-controlled multicenter study on efficacy of phosphatidylserine administration — [RCT]View study →}.

The catch: when the same 300 mg/day design was repeated with soy-derived PS in 120 AAMI subjects, it did not significantly outperform placebo ^{3Reference 3Jorissen et al. · 2001The influence of soy-derived phosphatidylserine on cognition in age-associated memory impairment — [controlled trial, null]View study →}.

Later soy-PS work (e.g. 100–300 mg/day in Japanese elderly with memory complaints) reported gains but often without a clear placebo separation ^{4Reference 4Kato-Kataoka et al. · 2010Soybean-derived phosphatidylserine improves memory function of the elderly Japanese subjects with memory complaints — [trial]View study →}, and a 2010 RCT of PS conjugated to omega-3 (PS-DHA, 300 mg/day, 15 weeks) improved memory only in a more-impaired subgroup ^{5,6Reference 5Vakhapova et al. · 2010RCTPhosphatidylserine containing omega-3 fatty acids may improve memory abilities in non-demented elderly with memory complaints — [RCT]View study →Reference 6Vakhapova et al. · 2014RCTPhosphatidylserine containing omega-3 fatty acids may improve memory abilities in non-demented elderly: open-label extension — [RCT extension]View study →}.

More recently, a 2025 double-blind RCT of a PS-containing food supplement in Chinese older adults with mild cognitive impairment reported improved cognitive scores versus placebo ^{22Reference 22Zhang et al. · 2025RCTEffects of a food supplement containing phosphatidylserine on cognitive function in Chinese older adults with mild cognitive impairment: a randomized double-blind, placebo-controlled trial — [RCT]View study →} — a rare modern positive signal, though it tested a multi-ingredient supplement rather than PS alone.

Gap: the pivotal benefit was shown with a source (bovine cortex) that is no longer sold; modern soy/sunflower PS has weaker and less consistent support.

Hirayama et al. gave 200 mg/day soy-PS to 36 children (4–14 y) for 2 months and reported significant improvement in ADHD symptoms and short-term auditory memory, with no adverse effects ^{7Reference 7Hirayama et al. · 2014RCTThe effect of phosphatidylserine administration on memory and symptoms of attention-deficit hyperactivity disorder — [RCT]View study →}.

A larger trial of PS conjugated to omega-3 (PS-Omega3) in 200 children showed benefit mainly in a hyperactive-impulsive, emotionally dysregulated subgroup during the double-blind phase, with broader gains during open-label extension ^{8Reference 8Manor et al. · 2012RCTThe effect of phosphatidylserine containing omega-3 fatty acids on ADHD symptoms in children — [RCT with open-label extension]View study →}.

An earlier RCT of n-3 fatty acids delivered as phospholipids in inattentive children also linked improved blood fatty-acid status to better visual sustained attention ^{20Reference 20Vaisman et al. · 2008RCTCorrelation between changes in blood fatty acid composition and visual sustained attention performance in children with inattention: effect of dietary n−3 fatty acids containing phospholipids — [RCT]View study →}, consistent with the omega-3-conjugated results. A 2021 systematic review and meta-analysis concluded that PS produced a small, statistically detectable reduction in ADHD symptoms but flagged the small number of trials, small samples, and short duration as limiting confidence ^{9Reference 9Bruton et al. · 2021Meta-analysisPhosphatidylserine for the treatment of pediatric attention-deficit/hyperactivity disorder: a systematic review and meta-analysis — [meta-analysis]View study →}.

Gap: only a handful of small, short RCTs — some manufacturer-funded — and the omega-3 co-formulation makes it hard to isolate PS’s own contribution.

High-dose PS blunts the neuroendocrine stress response. Monteleone et al. showed that intravenous bovine PS (50–75 mg) reduced the ACTH and cortisol rise after exercise ^{10Reference 10Monteleone et al. · 1990Effects of phosphatidylserine on the neuroendocrine response to physical stress in humans — [controlled trial]View study →}, and that 800 mg/day orally for 10 days blunted the ACTH/cortisol response to physical stress in healthy men ^{11Reference 11Monteleone et al. · 1992Blunting by chronic phosphatidylserine administration of the stress-induced activation of the hypothalamo-pituitary-adrenal axis in healthy men — [controlled trial]View study →}.

Oral results at lower, supplement-realistic doses are weaker and dose-dependent: 600 mg/day attenuated cortisol in one exercise study ^{12Reference 12Starks et al. · 2008RCTThe effects of phosphatidylserine on endocrine response to moderate intensity exercise — [RCT]View study →}, while other trials at 300–750 mg/day found effects on mood or capacity but not a clear cortisol change ^{13,18,21Reference 13Kingsley et al. · 2006RCTEffects of phosphatidylserine on exercise capacity during cycling in active males — [RCT]View study →Reference 18Parker et al. · 2011RCTThe effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exercise — [RCT, industry]View study →Reference 21Benton et al. · 2001The influence of phosphatidylserine supplementation on mood and heart rate when faced with an acute stressor — [trial]View study →}.

Gap: the clearest effects used high or intravenous doses of bovine PS; benefit at typical 100–300 mg/day oral soy-PS doses is inconsistent.

Several 1980s–90s double-blind trials of bovine PS (usually 300 mg/day) in Alzheimer’s and senile dementia reported short-term improvement on cognitive and behavioral scales, most apparent in milder cases ^{14,15,16Reference 14Delwaide et al. · 1986RCTDouble-blind randomized controlled study of phosphatidylserine in senile demented patients — [RCT]View study →Reference 15Engel et al. · 1992RCTDouble-blind cross-over study of phosphatidylserine vs. placebo in patients with early dementia of the Alzheimer type — [RCT]View study →Reference 16Amaducci · 1988RCTPhosphatidylserine in the treatment of Alzheimer’s disease: results of a multicenter study — [RCT]View study →}. These effects were modest and tended to fade over months, and PS is not disease-modifying — it does not alter the underlying course of Alzheimer’s.

Gap: short, dated trials with bovine PS; no evidence that modern PS treats or slows dementia, and the FDA health claim explicitly excludes a treatment claim.

Soy-PS at 750 mg/day for 10 days improved exercise capacity (time to exhaustion) in active men in a small crossover trial ^{13Reference 13Kingsley et al. · 2006RCTEffects of phosphatidylserine on exercise capacity during cycling in active males — [RCT]View study →} and altered markers of oxidative stress/soreness after intermittent running ^{17Reference 17Kingsley et al. · 2005RCTEffects of phosphatidylserine on oxidative stress following intermittent running — [RCT]View study →}. Endocrine effects across exercise studies are equivocal, and sample sizes are small (10–16 subjects).

Gap: small, short crossover studies with inconsistent endocrine findings; ergogenic benefit is not well established.

Evidence that PS sharpens cognition in healthy, non-impaired adults is thin. A manufacturer-run acute study reported faster processing speed and better accuracy after 400 mg PS before exercise ^{18Reference 18Parker et al. · 2011RCTThe effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exercise — [RCT, industry]View study →}, but replication in healthy people is limited, and a 2025 RCT of sunflower-PS in healthy children aged 8–12 showed only narrow cognitive effects ^{23Reference 23Research team · 2025RCTThe cognitive effects of supplementation with sunflower phosphatidylserine in healthy children aged 8 to 12 years: a randomized controlled trial — [RCT]View study →}.

Gap: almost no independent, adequately powered data in healthy adults; most positive signals come from impaired populations or industry studies.