Phosphatidylserine is a phospholipid found in high concentrations in the brain and has been studied mostly for its cognitive and neuroprotective effects. Its use in supporting the adrenal glands is based on a small body of scientific literature suggesting that phosphatidylserine may help modulate the body's stress response, particularly through its influence on cortisol levels. Cortisol is a hormone produced by the adrenal glands in response to stress. Several small clinical studies and pilot trials have shown that phosphatidylserine supplementation (typically 400-800 mg per day) can attenuate the rise in cortisol following acute physical or mental stress. This effect has been observed in both athletes and non-athletes.

The proposed mechanism is that phosphatidylserine may interact with cell membranes and signaling pathways involved in hypothalamic-pituitary-adrenal (HPA) axis regulation, thereby blunting excessive cortisol output. However, these findings are relatively modest and not universally replicated. The number of well-controlled, large-scale human studies is limited, and the direct effect of phosphatidylserine on overall adrenal gland health or long-term adrenal function has not been conclusively demonstrated. Most evidence relates to short-term cortisol modulation rather than direct adrenal support.

In summary, there is some scientific evidence that phosphatidylserine can influence stress-related cortisol levels, which are directly linked to adrenal function, but the evidence is limited and does not strongly support its routine use for broader adrenal gland support.