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Phosphatidylserine: what it is and what it does for memory

By the Life in Good Form editors. Updated 2026-10-15.

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Quick answerPhosphatidylserine (PS) is sold as a supplement mainly for memory. In a 6-month randomized trial in 78 older Japanese adults with memory complaints, soy PS at 100 or 300 mg a day improved memory scores only in people who started with lower scores; scores rose in all groups, including placebo. A 12-week pilot study found improvements but had no placebo group. The FDA allows a qualified health claim for PS and cognitive dysfunction, not an approval for treating dementia.
Our picks at a glance
  • Phosphatidylserine 100 mg capsules. Best for: Older adults with memory complaints who want the studied form. See options on Amazon
  • Sunflower-derived phosphatidylserine. Best for: People avoiding soy. See options on Amazon
  • Phosphatidylserine 300 mg servings. Best for: People who want the higher studied dose in fewer capsules. See options on Amazon

Compare the picks and what to watch out for

What phosphatidylserine is

A 2010 study in the Journal of Clinical Biochemistry and Nutrition describes soybean-derived PS as made from soybean lecithin by an enzymatic reaction with the amino acid L-serine.

A 2013 pilot study in Clinical Interventions in Aging notes soy PS may serve as a safe alternative to phosphatidylserine extracted from bovine cortex. Supplements today may list soy or sunflower lecithin as the source.

What the research shows

StudyFinding
2010 RCT, 78 adults aged 50 to 69, 6 months, 100 or 300 mgMemory improved only in those with lower starting scores; all groups improved, including placebo
2013 pilot, 30 adults aged 50 to 90, 12 weeks, 300 mgBetter memory recall, recognition and mental flexibility; no placebo group

The 2010 trial. Neuropsychological scores increased similarly across all groups, including placebo. Among people with relatively low scores at baseline, memory improved in the PS groups but not on placebo, mostly through better delayed verbal recall, a skill that weakens in the earliest stage of dementia. No side effects were seen.

The 2013 pilot. After 12 weeks of 300 mg soy PS, memory recognition, memory recall, executive function and mental flexibility improved. Unexpectedly, blood pressure fell. Without a placebo group, these results are exploratory.

Other phosphatidylserine studies

These studies are small and often tested blends, so they add hints rather than proof.

The FDA qualified health claim

The FDA lists letters of enforcement discretion for a qualified health claim on phosphatidylserine and cognitive dysfunction and dementia, first issued in 2003 and updated in 2004. It does not mean PS has been proven to prevent or treat dementia.

Safety

How to choose a phosphatidylserine supplement

What to look for when you buy

Phosphatidylserine 100 mg capsules

Best for: Older adults with memory complaints who want the studied form

NOW Foods provides 100 mg PS per capsule, 1 to 3 times daily with food, matching the 100 to 300 mg studied range.

Watch out: Also contains choline and inositol. Evidence is limited; see a doctor for memory changes.

See options on Amazon

Sunflower-derived phosphatidylserine

Best for: People avoiding soy

Some PS products are made from sunflower lecithin instead of soy.

Watch out: The memory trials summarized here used soy-derived PS.

See options on Amazon

Phosphatidylserine 300 mg servings

Best for: People who want the higher studied dose in fewer capsules

The 2013 pilot and one 2010 group used 300 mg a day.

Watch out: Check the PS amount per capsule and any added ingredients.

See options on Amazon
When to talk to a doctor: See a doctor about new or worsening memory problems before relying on a supplement. Talk with your doctor before taking phosphatidylserine if you take blood pressure or other medicines, have a soy allergy, or are pregnant or nursing.

Questions people ask

What is phosphatidylserine?
A compound sold as a supplement for memory; the studies here used soybean-derived PS made from soy lecithin.
What does phosphatidylserine do for memory?
In a 6-month trial, soy PS improved memory only in older adults who started with lower scores. Evidence is limited.
How much phosphatidylserine should I take?
Studies used 100 mg to 300 mg a day. Follow the label.
Is phosphatidylserine safe?
Studies reported no serious side effects. One study found lower blood pressure, so check with your doctor if you take blood pressure medicine.
Does the FDA approve phosphatidylserine for dementia?
No. The FDA has issued letters allowing a qualified health claim, which is not a drug approval.

Sources

Sources checked 2026-10-15.

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