Cordyceps

Proposed mechanism

Cordycepin is an adenosine analog. In mouse Leydig cells and in live mice, it activates adenosine receptors and cAMP-PKA signaling, raising steroidogenic acute regulatory protein (StAR) expression and baseline testosterone output. This is animal and cell-culture research only — no human trial has tested Cordyceps against a testosterone endpoint, and the effect is not one-directional even in animals: several studies from the same line of work found Cordyceps extracts lowered testosterone production when cells were co-stimulated with hCG/LH, the pituitary signal that normally drives it. The one controlled human trial to measure hormones during supplementation used a multi-ingredient blend containing Cordyceps and found no change in testosterone. Separately, Cordyceps extract raised the ATP-to-phosphate ratio in mouse liver, the animal basis for "more cellular energy" claims. Human exercise trials are largely null; one small trial in older adults improved lactate threshold with no change in VO2max.

Mechanisms describe how researchers think a compound may act, often from laboratory work — a proposed mechanism is not proof of a clinical effect in people.