Phosphatidylserine and Cortisol: What the Research Really Shows

This phospholipid may take the edge off stress hormones, especially around hard exercise.

Track the foods that fit your goals. Track it free with Ration →

By the Ration Editorial Team · Reviewed against primary research · Updated July 14, 2026

Phosphatidylserine is a phospholipid, a type of fat that makes up the membranes of every cell in your body.

It is especially concentrated in brain cells, where it helps regulate how cells signal to each other.

Small amounts come from food, but most supplements today are made from soy lecithin or sunflower lecithin rather than the cow brain extracts used decades ago.

Cortisol is the body's main stress hormone, released by the adrenal glands as part of the hypothalamic pituitary adrenal (HPA) axis response to physical or psychological stress.

Phosphatidylserine appears to dampen this HPA axis response, meaning less cortisol gets released when the body is under strain.^[4]

Researchers think it may act at the level of the pituitary or hypothalamus, blunting the signal that tells the adrenal glands to ramp up cortisol output.^[5]

Our database grades the phosphatidylserine to cortisol relationship as an A, meaning the direction of effect (decrease) is well supported and consistent across the studies we have.

• ↓CortisolAHuman trials

  Research may lower Cortisol · strong agreement · 5 studies

  View 5 studies on PubMed

  • Blunting by chronic phosphatidylserine administration of the stress-induced activation of the hypothalamo-pituitary-adrenal axis in healthy men (1992)
  • Effects of phosphatidylserine on the neuroendocrine response to physical stress in humans (1990)
  • The effects of phosphatidylserine on endocrine response to moderate intensity exercise (2008)
  • Effects of phosphatidylserine on oxidative stress following intermittent running (2005)
  • Nutritional and botanical interventions to assist with the adaptation to stress (1999)

An early randomized controlled trial in healthy men found that chronic phosphatidylserine administration blunted the stress induced activation of the HPA axis compared to placebo.^[4]

A related trial looked specifically at the neuroendocrine response to physical stress and found similar cortisol blunting effects.^[5]

More recent work has focused on exercise. One study found phosphatidylserine reduced the endocrine (cortisol) response to moderate intensity exercise.^[1]

Another study examined intermittent running and oxidative stress markers alongside phosphatidylserine supplementation, again reporting favorable hormonal shifts.^[2]

Older review work has also grouped phosphatidylserine among nutritional and botanical interventions that may assist the body's adaptation to stress, though this kind of narrative review carries less weight than a controlled trial.^[3]

Taken together, these are mostly small human trials, some decades old, focused on exercise induced or acute stress rather than everyday chronic stress. That is an important caveat for anyone hoping this translates directly to daily life stress management.

• Soy lecithin, the main source used in modern supplements
• Sunflower lecithin, a soy free alternative
• White beans
• Egg yolks
• Organ meats, such as liver
• Fish, particularly mackerel and herring

Dietary intake from these foods is generally modest, which is why most research trials use concentrated supplement forms rather than relying on food alone.

Studies investigating cortisol and stress response have used doses ranging from around 200 mg to 800 mg per day.^[1][4][5]

Some trials administered phosphatidylserine for several weeks before measuring hormonal effects, suggesting benefits may build with consistent use rather than appearing after a single dose.^[4]

Exercise focused studies have sometimes used shorter loading periods timed around a bout of intense activity, such as running.^[1][2]

Phosphatidylserine has generally been well tolerated in the human trials available, with no major safety signals reported in the studies cited here.

As with any supplement, quality and sourcing matter. Modern soy or sunflower derived products differ from the bovine cortex extracts used in some of the earliest research.

People on blood thinners or with bleeding disorders, and those who are pregnant or breastfeeding, should be especially cautious given the limited safety data in these groups.

• Endurance or high intensity athletes looking to blunt exercise induced cortisol spikes^[1][2]
• People interested in the biology of the HPA axis and stress hormone regulation^[4][5]
• Anyone curious about phospholipid based supplements as part of a broader stress management approach

Phosphatidylserine is not a substitute for sleep, recovery, or stress management basics, and the evidence here centers on cortisol levels rather than subjective stress or mood.

Across five human studies in our database, phosphatidylserine consistently shows an association with lower cortisol responses to physical or acute stress, earning an A evidence grade.

The research is still fairly narrow, focused mostly on exercise and acute stress paradigms in relatively small samples, so it is reasonable to view this as promising rather than definitive.