Black galingale (Kaempferia parviflora), also known as Thai black ginger or "Krachai Dam," has a long-standing history in traditional Thai and Southeast Asian medicine for supporting male reproductive health and vitality. Traditionally, it has been used as an aphrodisiac, to boost libido, and to enhance overall sexual function. The rhizome is believed to increase energy, stamina, and sexual performance, particularly in men.

Several animal studies and a small number of preliminary human trials have investigated its effects on the reproductive system, particularly in relation to male sexual function. Some of these studies have shown that extracts of black galingale may improve erectile function and increase sperm quality in animal models, while limited human studies suggest a potential benefit for erectile function and increased subjective sexual satisfaction. The presumed mechanism involves enhancement of nitric oxide production and improved blood flow, as well as possible androgenic effects.

However, the scientific evidence is not yet robust: most studies are small, short-term, and sometimes lack rigorous controls. Therefore, the primary justification for using black galingale to support the reproductive system is traditional, with moderate preliminary support from scientific research, but further high-quality clinical trials are needed to confirm efficacy and safety.