Epimedium, commonly known as "Horny Goat Weed," has a long history of traditional use in Chinese medicine to support reproductive health, particularly sexual function and libido in both men and women. Historical texts and anecdotal reports suggest that it was used to address conditions such as erectile dysfunction and low libido, attributed to its purported ability to "tonify the kidney yang" in traditional Chinese medicine theory, which is linked to vitality and reproductive capacity.

Modern scientific investigations have identified icariin as the primary active compound in Epimedium, and some laboratory and animal studies suggest that it may have effects on sexual function, such as improving erectile function by inhibiting the PDE5 enzyme, similar to the mechanism of some pharmaceutical drugs used to treat erectile dysfunction. However, rigorous human clinical trials are limited, and the quality of available studies is generally low, with small sample sizes and methodological weaknesses.

Overall, while there is some preliminary scientific rationale for its use and a strong foundation in traditional medicine, the evidence supporting Epimedium for reproductive system support is not robust by modern scientific standards. Therefore, its use is primarily justified by tradition, with modest scientific support.