Phosphatidylserine

The verdict

Is Phosphatidylserine worth taking?

Phosphatidylserine has a real, if modest, ability to blunt the cortisol spike from intense exercise and acute stress. Dosing in the research is somewhat inconsistent, studies have used anywhere from 400 to 800 mg with varying results, but 600 to 800 mg daily for short periods (10 to 15 days) around demanding training blocks is the most commonly supported protocol. This is not a tool for improving athletic performance directly, the cortisol blunting does not reliably translate into better strength or power output. Soy or sunflower-derived PS is the modern standard; the original bovine brain-derived form is no longer used due to BSE safety concerns.

What it does

What Phosphatidylserine does in the body

Exercise-induced and acute stress-induced cortisol blunting. Phosphatidylserine is a phospholipid concentrated in cell membranes throughout the body, particularly in the brain. In a stress or intense exercise context, it appears to reduce ACTH stimulation of the adrenal glands, resulting in a smaller cortisol rise than would otherwise occur. This is a useful tool for managing the catabolic load of very demanding training blocks, though it should be understood as cortisol management rather than a direct performance enhancer.

The evidence

What the research actually shows

Moderate. Several small, mostly older randomized controlled trials in the cortisol-blunting application are consistent in direction but limited in scale, several involving only 8 to 11 subjects. A 600 mg dose over 10 days demonstrated a meaningful reduction in exercise-induced cortisol rise in a well-controlled crossover study, with an interesting secondary finding of higher testosterone in the treatment group. Studies at 800 mg in trained athletes found a roughly 20% reduction in cortisol rise. The overall picture is a real but modest effect with no strong evidence it translates into improved strength, power, or body composition outcomes.

Food first

Getting Phosphatidylserine from food

Soy lecithin and egg yolks contain phosphatidylserine but at concentrations far below the therapeutic doses used in research. There is no practical food-first route to the doses shown to meaningfully blunt exercise-induced cortisol.

What the guide adds

The part that is not on this page

Everything above is the assessment. What the guide adds for Phosphatidylserine is the protocol:

• Optimal Form
• Bioavailability
• Purity Red Flags
• Stack With / Avoid

147 entries across nine categories, every one graded against the clinical literature the same way.

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About the author

Who graded this

Daniel Edlund is a Le Cordon Bleu-trained private chef in Los Angeles, a certified personal trainer and strength coach, and an internationally licensed massage therapist. Thirty years of strength training and fifteen years cooking in private estate kitchens. He is the author of The Complete Supplement Guide, which grades 147 entries against the clinical literature, and of The EASY Way to Organic Cooking, first published in 2013.

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This page is information, not medical advice. Supplements interact with prescription medication and with each other, and the right answer depends on your own bloodwork and history. Talk to your doctor before starting anything, particularly if you are pregnant, nursing, managing a health condition, or already taking medication.

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All 147 entries, graded →