A new human study published by Medical Cannabis and Cannabinoids found that short-term, high-dose CBD use was associated with increased testosterone levels in men, while also affecting other steroid hormones involved in endocrine regulation.
Researchers from the University of Florida and Tufts University School of Medicine conducted a randomized, placebo-controlled crossover study involving 12 healthy adults, including six men and six women. Participants received either a placebo or 750 milligrams of oral CBD twice daily for three days, followed by one additional 750-milligram dose on the fourth day.
The CBD used in the study was Epidiolex, an FDA-approved cannabis-derived cannabidiol medication used to treat seizures associated with Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex.
Researchers found that testosterone levels increased significantly among male participants after CBD administration, with mean levels rising 1.44-fold compared with placebo. However, the authors noted that testosterone levels remained within normal physiological ranges.
The study also found that CBD was associated with a significant decrease in 21-OH-progesterone, a precursor steroid hormone, while cortisol and corticosterone levels increased among participants who received CBD. Researchers found no significant difference in cholic acid levels between the CBD and placebo groups.
According to the study, the findings provide evidence that CBD can modulate key components of the steroidogenic and endocrine systems in humans. The authors said the effects may be related to CBD’s interaction with the endocannabinoid system, including CB1 receptors involved in the hypothalamic-pituitary-adrenocortical and hypothalamic-pituitary-gonadal axes, though they emphasized that the mechanisms remain speculative.
Researchers also cautioned that the study had several limitations, including its small sample size and the high dose of CBD used. The 1,500 milligrams per day administered in the study is higher than the amount commonly found in many over-the-counter CBD products.
In addition, all participants received methylphenidate on the final clinical day as part of a separate study objective. Although researchers said the dose was unlikely to have significantly affected hormone levels on its own, they acknowledged that a combined effect with CBD could not be ruled out.
The study concludes that while the hormonal changes were statistically significant, it remains unclear whether they have meaningful clinical significance. Researchers said larger studies are needed to better understand the potential endocrine effects of CBD, particularly with different doses and longer-term use.
