Phosphatidylserine (PS) is a phospholipid component found in cell membranes, particularly in the brain. Its use as a dietary supplement is primarily linked to cognitive health, memory, and stress response. Regarding support for the hypothalamus, the evidence is indirect. The hypothalamus is a key brain region involved in regulating the body's stress response via the hypothalamic-pituitary-adrenal (HPA) axis. Several clinical studies have examined PS supplementation and its effects on the HPA axis, particularly how the body responds to physical and mental stressors.

Some small-scale studies suggest that PS may help modulate cortisol levels—the primary stress hormone regulated by the hypothalamus—and blunt the rise in cortisol in response to acute stress, indicating a potential supportive role for hypothalamic function. For example, research has shown PS supplementation may reduce cortisol output and perceived stress during intensive exercise or mental challenges.

However, these effects are modest, and the research is not robust or specific to hypothalamic function per se; rather, it is focused on downstream effects mediated by the HPA axis. There is no strong evidence PS directly supports the hypothalamus outside of this stress modulation context. Therefore, while there is some scientific rationale for its use, the evidence is limited and not conclusive.