Supplement analysis backed by scientific evidence · PT

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Limited evidenceBrain & cognition

Phosphatidylserine

The encouraging memory trials used bovine-cortex phosphatidylserine, which was pulled from the market over BSE concerns. The soy- and sunflower-derived product you can actually buy has repeatedly failed to reproduce those results — the FDA itself allows only a qualified claim noting the evidence is "very limited and preliminary."

What the science says

  • Memory in older adults (bovine-derived) Moderate evidence

    The largest trial of the original bovine-cortex form randomized 425 elderly people with cognitive decline to 300 mg/day or placebo for 6 months, finding modest improvements on behavioural and cognitive rating scales. This product is no longer sold because of transmissible spongiform encephalopathy risk, so the result does not transfer to what is on shelves today.

  • Memory with soy-derived phosphatidylserine Limited evidence

    A controlled trial in 120 older adults with age-associated memory impairment gave 300 mg or 600 mg/day of soy-derived phosphatidylserine for 12 weeks and found no significant benefit on any cognitive outcome versus placebo. Later soy and sunflower trials have been small, often multi-ingredient, and inconsistent — the plant-derived molecule has a different fatty acid profile from the bovine form, which is the leading explanation for the failure to replicate.

  • Exercise-induced cortisol and stress Limited evidence

    Small trials using 600-800 mg/day have reported blunted cortisol and ACTH responses to intense exercise, and a few report improved mood or reduced perceived stress. Sample sizes are typically under 20, results are inconsistent, and no effect on actual training outcomes or performance has been established.

  • Attention in children with ADHD Limited evidence

    A handful of small randomized trials, mostly 200-300 mg/day for 2-4 months, report improvements in attention and impulsivity ratings. The trials are few, small, and often industry-supported, and none has been independently replicated at scale.

Dosage & safety

Studied doseOlder-adult cognition trials used 300 mg/day, usually split into three 100 mg doses with meals. Exercise-cortisol studies used 600-800 mg/day. Most consumer products supply 100-300 mg/day of soy- or sunflower-derived phosphatidylserine. Allow at least 8-12 weeks for any cognitive effect.
SafetyWell tolerated overall; the most common complaints are mild GI upset and insomnia, the latter mostly at doses above 300 mg/day taken late in the day. Because phosphatidylserine is involved in platelet surface signalling, an additive bleeding risk with warfarin, DOACs, clopidogrel or high-dose fish oil is plausible but not clinically documented — caution if you are anticoagulated. Bovine-cortex-derived product is best avoided entirely on TSE grounds; soy-derived forms are unsuitable for people with soy allergy (sunflower-derived is an alternative). In the US, the FDA permits only a qualified health claim explicitly stating that the supporting evidence is very limited and preliminary — a fair summary. Not a banned substance in sport.

Scientific references

Where to buy

Double Wood Supplements, Phosphatidyl Serine, 120 Capsules (150 mg per Capsule)

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