Is BDNF useful for fertility?

BDNF (Brain-Derived Neurotrophic Factor) is primarily known for its role in neuronal survival and plasticity. Emerging research suggests it also plays a role in reproductive physiology, including follicular development, oocyte maturation, and endometrial receptivity. Some studies have found associations between BDNF levels and fertility outcomes, such as in vitro fertilization success. However, the evidence is still preliminary and not robust enough to recommend BDNF as a clinical biomarker for fertility. Most studies are observational with small sample sizes, and causality is unclear. Moreover, consumer DNA tests that report BDNF gene variants (e.g., Val66Met) are not validated for fertility prediction. Lifestyle factors, age, and hormonal status have a much larger impact. Therefore, while BDNF is an interesting molecule, it is not currently useful for guiding fertility decisions. Evidence: human-moderate (observational studies). Caveat: not a substitute for standard fertility evaluation.