Phosphatidylserine
Summary
Phosphatidylserine is a membrane phospholipid. Older trials of cow-brain PS in elderly people with memory problems reported better memory and behaviour scores (grade C). Trials of the soy-derived PS sold today are mixed: one found no effect, another found gains only in low scorers. Studied doses were 100 to 600 mg a day.
Key facts
- A phospholipid in cell membranes; early trials used PS from cow brain cortex (BC-PS), later trials used soy-derived PS[4]
- Memory and behaviour in older adults (C, mostly cow-brain PS); memory with soy PS (mixed, C); cortisol response to exercise (D); ADHD symptoms in children (D)[1][2][3][5][6][7]
- The largest positive trials used cow-brain PS; a 12-week trial of soy PS at 300 or 600 mg/day found no effect on memory[1][3]
- Soy PS up to 600 mg/day for 12 weeks showed no changes in blood safety tests, blood pressure or heart rate in older adults[4]
- 6 graded human outcomes on this page
- October 11, 2026
How it works
ProposedPS is a phospholipid component of cell membranes; how oral supplements affect brain function in people is not established.[4]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Focus | Grade C | Improved | RCT · n = 494 · 1993 | 5 rows |
| Stress | Grade D | Improved | Crossover RCT · n = 10 · 2008 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Memory and behaviour in elderly people with cognitive decline | Improved | Grade C | RCT · n = 494 · 1993 Adults aged 65–93 with moderate to severe cognitive decline, 23 Italian centres Form: Bovine cortex phosphatidylserine (BC-PS) · Dose: 300 mg/day · Duration: 6 months Behaviour and memory test scores improved more than with placebo; 69 people dropped out, and PS was well tolerated. | 8323999 (opens PubMed)Source [1] |
| Memory in age-associated memory impairment | Improved | Grade C | RCT · n = 149 · 1991 Older adults with age-associated memory impairment Form: Bovine cortex phosphatidylserine (BC-PS) · Dose: 100 mg three times a day · Duration: 12 weeks Learning and memory test scores improved versus placebo, mainly in people who scored lowest at the start. | 2027477 (opens PubMed)Source [2] |
| Memory in older adults with memory complaints | Mixed | Grade C | RCT · n = 78 · 2010 Japanese adults aged 50–69 with memory complaints Form: Soy-derived phosphatidylserine · Dose: 100 or 300 mg/day · Duration: 6 months Scores rose similarly in all groups including placebo; in people with low starting scores, memory (mainly delayed verbal recall) rose with PS but not placebo. | 21103034 (opens PubMed)Source [5] |
| ADHD symptoms and short-term memory in children | Improved | Grade D | RCT · n = 36 · 2014 Children aged 4–14 with ADHD not on drug treatment Form: Phosphatidylserine · Dose: 200 mg/day · Duration: 2 months ADHD symptom scores and short-term auditory memory improved versus placebo. | 23495677 (opens PubMed)Source [7] |
| Cortisol response to moderate exercise | Improved | Grade D | Crossover RCT · n = 10 · 2008 Healthy men Form: Phosphatidylserine · Dose: 600 mg/day · Duration: 10 days The rise in cortisol during cycling was blunted compared with placebo. | 18662395 (opens PubMed)Source [6] |
| Memory and cognition with soy PS | No effect | No effect | RCT · n = 120 · 2001 Adults over 57 with age-associated memory impairment Form: Soy-derived phosphatidylserine · Dose: 300 or 600 mg/day · Duration: 12 weeks plus 3-week wash-out Neither dose changed memory or other cognitive measures compared with placebo. | 11842880 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Soy- or sunflower-derived PS | Varies[4][3][5] | No head-to-head human absorption data in our sources.[4][3][5] | Up to 600 mg/day of soy PS was tolerated for 12 weeks in older adults.[4][3][5] | Memory in older adults (100–600 mg/day) |
| Bovine cortex PS (BC-PS) | Varies[1][4] | No comparative human absorption data in our sources.[1][4] | 300 mg/day was well tolerated for 6 months in a 494-person trial.[1][4] | Memory and behaviour in older adults (300 mg/day); used in early trials, not the form sold today |
Studied doses
Doses studied in human trials ranged from 100 to 600 mg of phosphatidylserine a day for 10 days to 6 months; 300 mg/day split into three doses was most common.[1][2][3][5][6]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Pregnancy and breastfeeding
- No safety data in pregnancy or breastfeeding were found in the trials we cite.[4]
- Soy allergy
- Most PS supplements are made from soy or sunflower lecithin; check which one the label lists.[4]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Where to buy Phosphatidylserine
Products from brands we partner with that contain Phosphatidylserine. Listing a product is not a claim that it works; check the amount per serving against the doses studied above, and the label for other ingredients.
- SupersmartPaid linkPS 100 (phosphatidylserine)3 tablets: 300 mg phosphatidylserine from 1,500 mg sunflower phospholipids (20% PS); 20 servingsShop at Supersmart (opens in new tab)Price and label checked 2026-10-11 on the brand’s site.
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Frequently asked questions
Does phosphatidylserine improve memory?
Trials of cow-brain PS in older adults reported better memory scores, but soy-PS trials are mixed: one 120-person trial found no effect.[1][2][3]
How much phosphatidylserine was studied?
Most trials used 300 mg a day split into three doses; the range was 100 to 600 mg.[1][3][5]
Is soy PS the same as the PS in older studies?
No. Early trials used PS from cow brain; soy-derived PS did not improve memory in a 120-person trial, so results may not carry over.[4][3]
Is phosphatidylserine safe?
In older adults, up to 600 mg of soy PS a day for 12 weeks caused no changes in blood safety tests or vital signs.[4]
Does PS lower cortisol?
In a 10-person crossover study, 600 mg a day for 10 days blunted the cortisol rise during exercise.[6]
Sources
- [1]Cognitive decline in the elderly: a double-blind, placebo-controlled multicenter study on efficacy of phosphatidylserine administration.. Aging (Milano), 1993. RCT
- [2]Effects of phosphatidylserine in age-associated memory impairment.. Neurology, 1991. RCT
- [3]The influence of soy-derived phosphatidylserine on cognition in age-associated memory impairment.. Nutr Neurosci, 2001. RCT
- [4]Safety of soy-derived phosphatidylserine in elderly people.. Nutr Neurosci, 2002. RCT
- [5]Soybean-derived phosphatidylserine improves memory function of the elderly Japanese subjects with memory complaints.. J Clin Biochem Nutr, 2010. RCT
- [6]The effects of phosphatidylserine on endocrine response to moderate intensity exercise.. J Int Soc Sports Nutr, 2008. crossover-RCT
- [7]The effect of phosphatidylserine administration on memory and symptoms of attention-deficit hyperactivity disorder: a randomised, double-blind, placebo-controlled clinical trial.. J Hum Nutr Diet, 2014. RCT
What changed
- Effect arrows corrected on 1 row(s): outcomes where a harmful measure fell (pain, symptoms, blood pressure, lipids, glucose, risk) now show as improved (up). No study data changed.
- First draft. Every PMID checked against NCBI E-utilities (title, year and journal taken from the PubMed record; retraction and expression-of-concern flags checked: none) and abstracts read for each cited row. Product details in Where to buy read from the brand page on the date shown.