Phosphatidylserine supplement: memory evidence and the doses studied

Phosphatidylserine (PS) has been studied for memory in older adults at roughly 100 to 600 mg a day, and the results are mixed: one 12-week trial found no effect, another found small gains only in people who started with lower memory scores. The US Food and Drug Administration allows only a heavily qualified claim for it, and the dose on a label matters far more than the name.

This guide explains what the research and the FDA letter say, why the source of the ingredient (soy or cow brain) changes how studies can be read, and how a "4% complex" on a label can hide a very small amount of the real thing.

Does phosphatidylserine help memory?

Phosphatidylserine is a phospholipid, a fat-like building block found in the membranes of cells in plants, animals and other living things. Supplements are sold on the idea that it supports brain cell membranes, but the human trials are what count, and they point in different directions.

• A Dutch trial found no effect. Researchers in Maastricht gave 120 adults over 57 with age-associated memory complaints a placebo, 300 mg or 600 mg of soy-derived PS daily. After 12 weeks there were no significant differences on any outcome, and the authors concluded that a daily PS supplement did not affect memory or other thinking skills in older people with memory complaints.
• A Japanese trial found a narrower result. Seventy-eight people aged 50 to 69 with memory complaints took soy PS at 100 mg or 300 mg a day, or placebo, for 6 months. Test scores rose in every group, including placebo. Only in the subgroup with relatively low scores at the start did memory scores in the PS groups rise above baseline, mainly in delayed verbal recall. The authors work at a company, the Yakult Central Institute, so read it as a small, single-company study.

Put side by side, those two studies show why the honest answer is "maybe, for some people, and not proven."

What did the FDA say about phosphatidylserine?

In 2003 the FDA reviewed a petition asking to allow claims that PS may reduce the risk of dementia and of cognitive dysfunction in the elderly. It looked at 10 intervention trials. In five of the ten, a very small number of outcome measures out of many reached statistical significance. The agency concluded there was no significant scientific agreement for the claims, and that most of the evidence did not support a relationship, with a few results offering very limited and preliminary support.

The FDA then said it would consider using enforcement discretion for qualified claims only if they carried a disclaimer, which ends with the sentence: "FDA concludes that there is little scientific evidence supporting this claim." The letter also says the evidence could not support a recommended daily intake level. If a sales page quotes a "FDA-recognized" claim for PS, it should also show that disclaimer next to it. It is a very low bar, not an endorsement.

Soy or bovine: why the source matters

The FDA letter names two sources of PS in the studies: bovine brain cortex (BC-PS) and soy lecithin (S-PS). It noted that the fatty acid makeup of the two differs, so they may be different substances with different biological activity, and that there is considerable uncertainty in applying results from one to the other. The letter says most of the studies it identified used bovine PS, and only two used soy PS. The FDA also said bovine-derived PS is acceptable only when the cattle were not born, raised or slaughtered in a country where BSE ("mad cow disease") exists.

A practical consequence: a page that cites an older bovine-PS trial to sell a soy-PS capsule is comparing two things the regulator says may not be the same. Ask which source the cited study used and which source the capsule uses.

What dose of phosphatidylserine did studies use?

The studies we opened cover a range of amounts:

Study	Source	Daily amount	Length
Maastricht trial (120 older adults)	Soy	300 mg or 600 mg	12 weeks
Japanese trial (78 older adults)	Soy	100 mg or 300 mg	6 months

A separate safety report from the Maastricht group followed the same 120 people and found no significant differences in blood tests, blood pressure, heart rate or adverse events, and concluded soy PS was safe for older people up to 200 mg three times a day. The studied range, in other words, is about 100 to 600 mg a day, and 300 mg is the most common amount. Those numbers are amounts of the actual phosphatidylserine, which brings us to the label problem.

The "4% complex" trap on supplement labels

Soy PS is made by treating soy lecithin with the amino acid serine and an enzyme. The FDA letter notes the PS content depends on the starting lecithin and the process, and that for one manufacturer the non-PS components ranged from 15% to 80% of the material. That means "PS" on a bottle can describe a mixture where PS is a minority.

That is exactly the issue our reviews flag on two brain formulas:

• The SonoVive review found a 125 mg "Phosphatidylserine 4% Complex," which would be only about 5 mg of actual phosphatidylserine, far under study doses.
• The ProMind Complex review found the same 125 mg "4% complex" wording and noted that it is unclear whether 125 mg is pure PS or the weight of a complex that is only 4% PS.
• The Advanced Memory Formula review found a clearer label with 150 mg of a PS complex from soy lecithin per two tablets, which our review compares with the Maastricht trial's 300 and 600 mg doses that showed no difference from placebo.
• The Neuro Plus review found PS inside a 609 mg proprietary blend of about 17 compounds, so its amount is not broken out at all.
• The NeuroXen review found PS listed with no amount anywhere.

For how we weigh stated versus hidden amounts, see how we review supplement offers.

A checklist before you buy a phosphatidylserine product

1. Find the Supplement Facts panel. If there is none, treat that as a warning sign.
2. Find the PS line. Does it say pure PS in mg, or a "complex" or a percentage? If a percentage appears, multiply to get the real PS amount.
3. Check the source (soy or bovine) and match it to the study the page cites.
4. Multiply by servings per day and compare with the 100 to 600 mg studied.
5. Check whether PS sits inside a proprietary blend. If it does, the dose cannot be verified.
6. If you have a soy allergy, read the allergen line and ask a pharmacist.
7. Read the refund terms on the order form. Our ClickBank refund guide shows how.
8. Tell your doctor or pharmacist what you plan to take.

Browse the offers in our brain and memory category to see how each handles these checks.

FAQ

How much phosphatidylserine should I take?

No dose is established for everyone. Studies used about 100 to 600 mg a day of soy PS in older adults for 12 weeks to 6 months, and the FDA said the evidence could not support a recommended daily intake. A doctor or pharmacist can advise you.

Is phosphatidylserine FDA approved?

No. The FDA does not approve supplements. In 2003 it said it would consider enforcement discretion for two qualified claims, each with a disclaimer saying there is little scientific evidence for them.

Is soy phosphatidylserine as good as the bovine kind used in early studies?

That is unknown. The FDA noted that the two sources may be different substances, so results from one may not carry over to the other.

Is phosphatidylserine safe?

In the Maastricht safety report, 120 older adults took up to 600 mg a day for 12 weeks with no significant differences in safety measures versus placebo. That does not cover longer use, and you should still check with a doctor, especially if you take medicines.