Does Phosphatidylserine Help With Stress and Focus?

Most people reach for phosphatidylserine (PS) because they want to feel steadier under pressure, or think more clearly when it matters. Both have been tested, though not equally.

If phosphatidylserine is new to you, our previous article covers what it is and how it works: What Is Phosphatidylserine and What Does It Do?

Phosphatidylserine and Stress: The Most Consistent Finding

The most specific result PS has produced involves cortisol, the hormone released under pressure.

In a three-week trial, four groups took a placebo or a soy-derived complex providing 400, 600 or 800 mg of PS a day alongside phosphatidic acid, before a standardised stress test. The 400 mg PS group showed a blunted cortisol response, and they reported less distress afterwards. The higher doses did nothing (1).

A later trial in 75 men tested the same complex over six weeks, at 400 mg PS with 400 mg phosphatidic acid, or half that. The 400 mg dose normalised the cortisol response, but only in men already chronically stressed. The 200 mg dose did nothing, and neither changed how stressed people said they felt (2).

In both trials it was 400 mg of PS with phosphatidic acid that steadied the rise in stress hormones, and in the later and larger one only in men already under long-term stress.

Phosphatidylserine, Focus and Mental Performance

Focus is what PS is marketed for most and studied for least. Four trials have measured it.

The one trial in healthy young adults measured mental speed. Eighteen men took 400 mg a day of soy PS or a placebo for two weeks, then did a timed mental arithmetic task before and after a heavy leg workout. On PS they worked 20% faster per calculation before the workout, though not after it (3). Accuracy did not improve significantly, and the study was funded by the ingredient's manufacturer.

A small trial in 36 children with attention deficit hyperactivity disorder (ADHD) reported improvements in auditory memory and attention after 200 mg a day of soy PS for two months (4). The participants had a diagnosed condition, and the ingredient manufacturer supplied the material and co-authored the paper.

A larger trial in 209 healthy children found no overall difference in attention or memory after 100 mg a day of sunflower-derived PS (5).

A conference abstract described 70 adults aged 35 to 65 with self-reported cognitive decline taking a marine-sourced PS, with psychomotor speed improving against placebo (6), though finger-tapping speed is not concentration and the finding has not yet appeared in a full paper.

How Much Phosphatidylserine Did the Trials Use?

In adults, the stress trials and the mental speed trial all found their effect at 400 mg of PS a day. The trial in children with ADHD used 200 mg. In the stress trials the PS came combined with phosphatidic acid, so those doses are not directly comparable with PS taken on its own.

It was taken every day, for two weeks to three months, before anything was measured. No trial has tested occasional use, or a single dose before a demanding day.

Is Phosphatidylserine Safe?

PS has been well tolerated. A 2023 review of seven randomised trials in healthy adults recorded no adverse events and no dropouts (7), and the wider literature reports no consistent pattern of serious side effects (8). Most trials were short, so long-term safety is less well characterised.

The Takeaway

For stress, the most consistent finding is a specific one: 400 mg of PS combined with phosphatidic acid altered the hormonal response to an acute stressor, and in the larger trial only in men who were already chronically stressed.

For focus, the evidence is still developing. A trial in healthy children found no difference, but healthy young men worked faster on a timed mental task and children with ADHD improved on attention.

Augment Life's Phosphatidylserine provides a 400 mg phosphatidylserine complex delivering 200 mg of PS per capsule, taken with food.

Read more: Does Phosphatidylserine Improve Memory?and How can we cope with the stress of daily life? and Does Ashwagandha Help With MTHFR and Chronic Fatigue Syndrome?

Literature Sources

1. Hellhammer J, Fries E, Buss C, et al. Effects of soy lecithin phosphatidic acid and phosphatidylserine complex (PAS) on the endocrine and psychological responses to mental stress. Stress. 2004;7(2):119-26. https://doi.org/10.1080/10253890410001728379
2. Hellhammer J, Vogt D, Franz N, et al. A soy-based phosphatidylserine/phosphatidic acid complex (PAS) normalizes the stress reactivity of hypothalamus-pituitary-adrenal-axis in chronically stressed male subjects: a randomized, placebo-controlled study. Lipids Health Dis. 2014;13:121. https://doi.org/10.1186/1476-511X-13-121
3. Parker AG, Gordon J, Thornton A, Byars A, Lubker J, Bartlett M, et al. The effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exercise. J Int Soc Sports Nutr. 2011;8:16. https://doi.org/10.1186/1550-2783-8-16
4. Hirayama S, Terasawa K, Rabeler R, Hirayama T, Inoue T, Tatsumi Y, Purpura M, Jager R. 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;27(Suppl 2):284-91. https://doi.org/10.1111/jhn.12090
5. Friling M, Jackson PA, Kennedy D, Dodd F, Smith E, Lavie A, Lopresti A, Ivanir E, Jalanka J. The cognitive effects of supplementation with sunflower phosphatidyl serine in healthy children aged 8 to 12 years: a randomized controlled trial. Nutr J. 2026;25:3. https://doi.org/10.1186/s12937-025-01264-9
6. Liu Y, Lu Y, Tang Y. Phosphatidylserine supplementation on psychomotor speed among healthy adults with subjective cognitive declines. Innov Aging. 2025;9(Suppl 2):igaf122.3233. https://doi.org/10.1093/geroni/igaf122.3233
7. Welch J, Bashir H, Daniels S. The effect of phosphatidylserine supplementation on athletic performance: a systematic review of randomized clinical trials. J Sports Sci Nutr. 2023;4(2):170-5. https://doi.org/10.33545/27077012.2023.v4.i2c.209
8. Hussain M, Khan I, Chaudhary MN, et al. Phosphatidylserine: a comprehensive overview of synthesis, metabolism, and nutrition. Chem Phys Lipids. 2024;264:105422. https://doi.org/10.1016/j.chemphyslip.2024.105422