Cistanche tubulosa is traditionally used in Chinese medicine as a "yang tonic," believed to enhance male vitality, libido, and reproductive function. These uses are rooted in historical texts like the Shen Nong Ben Cao Jing and later pharmacopoeias, where Cistanche is described as a remedy for impotence, infertility, and general weakness attributed to kidney yang deficiency—a concept in Traditional Chinese Medicine (TCM) that is often associated with symptoms of low testosterone in Western terms.

Scientific research on Cistanche tubulosa and testosterone is limited but growing. Some animal studies suggest that extracts of the plant may increase serum testosterone levels, improve sperm parameters, and enhance sexual behavior in rodents. The proposed mechanisms include antioxidant effects, modulation of the hypothalamic-pituitary-gonadal axis, and potential upregulation of steroidogenic enzymes. However, there is a lack of high-quality human clinical trials directly demonstrating efficacy in raising testosterone in men. The available evidence is insufficient for strong scientific validation but does provide a biological rationale for further study.

In summary, use of Cistanche tubulosa for low testosterone is primarily justified by traditional practice, with some preliminary preclinical support but limited human data. The evidence level is modest and should be interpreted with caution.