Protocol
Phosphatidylserine 300 mg/day (soy-derived)
Soy-derived phosphatidylserine has two randomized trials in older adults with memory complaints (Jorissen 2001, PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 11842880; Kato-Kataoka 2010, PMID 21103034).
Grade D, tested: a human randomized trial looked for a benefit on the endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score. graded and did not find one. How to read a grade →
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How this letter has changedLatest: October 2026 · Downgraded.
The soy-derived phosphatidylserine protocol held a C on the strength of Cenacchi et al. (Aging (Milano), 1993; PMID 8323999), a trial of bovine-cortex phosphatidylserine, a different product. The two randomized trials of the soy form in the population it is sold to, Jorissen et al. (Nutr Neurosci, 2001; PMID 11842880; 120 adults, 300 or 600 mg/day, 12 weeks) and Kato-Kataoka et al. (J Clin Biochem Nutr, 2010; PMID 21103034; 78 adults, 100 or 300 mg/day, 6 months), found no between-group difference from placebo An inactive substitute made to look like the real treatment, so participants cannot tell which one they received.. Under the published scale a product tested in its own form and population without benefit is Grade D on Route 2. The letter moved in October 2026 after an editor adjudication of a machine second check and five independent reviews; the search behind the move is recorded on the protocol.PMID 11842880 PMID 21103034 PMID 8323999
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This protocol is phosphatidylserine from soy at 300 mg a day, the form sold today. In two studies of older adults with memory complaints, it did no better than a dummy pill on memory. The older positive studies used a form made from cow brains, which is no longer sold. So the form people can buy was tested and did not help.
Soy-derived phosphatidylserine has two randomized trials in older adults with memory complaints (Jorissen 2001, PMID 11842880; Kato-Kataoka 2010, PMID 21103034). Neither found a difference from placebo across the whole group; Kato-Kataoka reported a gain within the subgroup with lower baseline scores. The positive trial on this record (Cenacchi 1993) used bovine-cortex phosphatidylserine, a different product. The Vakhapova 2010 trial used a PS + omega-3 combination, so it does not grade PS alone. Soy-derived form replaced the bovine brain source. Kosher: soy is pareve.
Why this gradeGrade D, tested, no benefit. The reasoning, and what the grade does not cover.
Grade D on Route 2: tested, no benefit. Soy-derived phosphatidylserine was given to older adults with memory complaints in two randomized placebo-controlled trials, Jorissen et al. (Nutr Neurosci, 2001; PMID 11842880; 120 adults, 300 or 600 mg/day, 12 weeks) and Kato-Kataoka et al. (J Clin Biochem Nutr, 2010; PMID 21103034; 78 adults, 100 or 300 mg/day, 6 months), and in neither did the treated groups separate from placebo.
WHAT THIS GRADE DOES NOT COVERbovine-cortex phosphatidylserine, the product in the positive 1993 trial (Cenacchi et al., PMID 8323999), which is a different preparation no longer sold and is graded on the supplement record; phosphatidylserine combined with omega-3 fatty acids or with phosphatidic acid, which are combination products graded, where they are graded at all, as combinations; doses above 600 mg/day, which no trial of the soy form has tested; and any population other than older adults with memory complaints, including children with attention disorders and adults under stress, where small trials exist and are not part of this grade.
A grade describes the human evidence for a named use. It is not advice, and it is not a judgment on any individual prescription. How the letters are decided →
The evidence, in fullFour papers, each linked to its PubMed record.
Jorissen et al. (Nutr Neurosci, 2001; PMID 11842880): soy phosphatidylserine 300 or 600 mg/day, 120 older adults with age-associated memory impairment, 12 weeks; no difference from placebo on the primary delayed-recall measures or any secondary outcome. Kato-Kataoka et al. (J Clin Biochem Nutr, 2010; PMID 21103034): soy phosphatidylserine 100 or 300 mg/day, 78 adults aged 50 to 69 with memory complaints, 6 months; every group including placebo improved and the only gain reported is within a low-baseline subgroup. Cenacchi et al. (Aging (Milano), 1993; PMID 8323999) is the positive trial and used BOVINE-cortex phosphatidylserine, not the soy form this protocol names. Vakhapova et al. (Dement Geriatr Cogn Disord, 2010; PMID 20523044) used a PS + omega-3 combination, labeled as such and not used to grade PS alone. Grade D on Route 2: the soy form was tested twice in the population it is sold to and did not separate from placebo.
A validated cognitive battery (RAVLT, COGTEL) at baseline and 12 weeks for memory applications in older adults. Subjective memory complaints monthly using a standardized scale. Soy-derived PS is the form with the most human trial data; bovine-derived PS was used in the earliest studies. The source on the product label.
Evidence notes: not independently replicated The same finding reproduced by a separate research group. A result seen once can be chance or bias; a replicated one is harder to explain away., randomized trial
Endpoint graded: Memory in older adults with memory complaints (functional)
Last reviewed: July 2026
Educational use only · Not medical advice · EBL grades published human evidence and does not recommend treatment. Stopping a prescription is a decision for your physician.
As studiedDose, form, population and duration for every use.
A grade describes the intervention that was tested. Where the product on the shelf differs from it, this says so.
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These statements have not been evaluated by the Food and Drug Administration. Any grade on this page describes the strength of published human trial evidence in the populations studied. It is not a recommendation for any individual and is not medical advice. Starting, stopping or changing any supplement or medication is a decision for your physician.
How EBL searched for the trials (1 search)
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phosphatidylserine[tiab] AND (soy[tiab] OR soybean[tiab] OR soy-derived[tiab]) AND (randomized controlled trial[pt] OR randomized[tiab]) AND humans[mesh]Grades move when new trials publish. A free monthly email lists every grade EBL moved, with the reason and the trial behind it: the sign-up is on the Evidence Log →