What it is
Horny goat weed refers to Epimedium species; icariin content, species identity, and contamination control are important because products vary widely.
Core function and why it is studied
Its composition or proposed mechanism makes cardiovascular function logical research areas. Studies therefore examine sexual-function and circulation-related measures. That biological connection explains why it is studied; it does not by itself establish a meaningful benefit.
What the evidence means
Reliable direct human evidence is not sufficient to support a product-wide benefit claim. Laboratory, animal, or traditional-use evidence should not be presented as a demonstrated human outcome.
How to compare products
Compare species, plant part, extract ratio, solvent, standardized constituents, serving amount, and contaminant testing.
