Three routes. The evidence behind them is not equally strong, and this page says so.
Horny goat weed contains icariin, which acts on the PDE5 enzyme — the same target as sildenafil and tadalafil — and is associated with nitric oxide activity and blood vessel relaxation.
That is a real, identified mechanism, which is more than can be said for a lot of botanical marketing. The caveat is that most of the supporting work is in animals or cell cultures rather than human trials, and icariin content varies enormously between supplement products.
It also cuts both ways. A genuine PDE5 effect is exactly why this ingredient carries genuine interaction warnings: with prescription ED medication, with nitrates, and with blood pressure drugs. It is documented to affect CYP3A4, the liver enzyme that processes a long list of prescriptions.
Tongkat Ali carries the strongest human research in this formula, studied for testosterone-related outcomes, fatigue and exercise performance over periods of weeks. Boron has some evidence relating to testosterone metabolism and bone health.
Saw palmetto acts on 5-alpha-reductase, the enzyme that converts testosterone to DHT. That is the same pathway finasteride and dutasteride work on, which is why combining them without medical advice is a bad idea rather than a neutral one.
Nettle leaf contributes nutrients and has traditional use in prostate and urinary support, frequently paired with saw palmetto in European formulations. Sarsaparilla and wild yam are traditional inclusions.
The wild yam claim needs correcting. Wild yam contains diosgenin, which laboratories use as a chemical starting material for manufacturing steroid hormones. The human body does not perform that conversion. Wild yam is regularly described in supplement marketing as a natural hormone precursor, and that description is simply not accurate. It is a traditional botanical, nothing more.
The overall frame: every rationale above comes from research on an ingredient studied on its own, at its own dose. Since this product does not publish its amounts, none of it can be connected to what is actually in the capsule. See each ingredient in detail →