Hibiscus sabdariffa, or roselle, is a flowering plant whose dried calyxes are brewed into a tart, deep-red infusion known as hibiscus tea. This beverage is popular globally for its flavor and potential health benefits, particularly for cardiovascular health. Testosterone is a steroid hormone that regulates muscle mass, bone density, and metabolic function. Given the tea’s widespread use as a traditional remedy, a common question is whether it affects the body’s endocrine system, specifically circulating testosterone levels.
Scientific Evidence Linking Hibiscus to Testosterone Levels
Direct research on the effect of standard hibiscus tea consumption on testosterone in human males is limited. Most available data comes from laboratory studies using animal models, which often involve administering concentrated extracts rather than typical brewed tea. These animal studies present a complex, dose-dependent picture regarding the herb’s influence on male reproductive hormones.
Some investigations in male rats suggest that lower concentrations of hibiscus extract might increase serum testosterone levels and sperm count. This potential effect reverses sharply when the dosage is significantly increased, demonstrating a non-linear relationship. Studies using high-dose aqueous extracts, equivalent to a much greater intake than a person would typically consume, have shown a significant reduction in both circulating testosterone and sperm parameters.
This reduction at higher concentrations contradicts the popular idea of hibiscus tea acting as a testosterone-boosting supplement. Scientific consensus, based primarily on animal toxicology studies, suggests that excessive consumption of concentrated extracts may negatively impact male reproductive function. The lack of human clinical trials confirming a testosterone-boosting effect means claims of the tea elevating these hormone levels should be viewed with skepticism.
Phytochemicals and Endocrine Interaction
The biological activity of hibiscus tea is attributable to its phytochemical content. These compounds include anthocyanins, which give the tea its red color, alongside various polyphenols and flavonoids like quercetin and protocatechuic acid. These compounds have antioxidant capabilities, which are linked to the tea’s benefits for blood pressure and cholesterol management.
The interaction of these compounds with the endocrine system is complex and may explain the varied results seen in animal studies. Some hibiscus components are considered phytoestrogens, plant-derived substances that can mimic or interfere with the body’s natural estrogen. In males, high levels of estrogenic compounds can potentially disrupt the hypothalamic-pituitary-gonadal (HPG) axis, the regulatory feedback loop that controls testosterone production.
Disruption of this axis could suppress the release of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) from the pituitary gland. Since LH signals the testes to produce testosterone, its suppression could result in the reduced testosterone levels observed in high-dose animal models. The strong antioxidant activity could also interfere with steroidogenesis, the pathway by which the body synthesizes testosterone.
Safe Consumption and Potential Drug Interactions
Hibiscus tea is considered safe when consumed in moderation, typically one to three cups per day. However, individuals taking certain medications must exercise caution due to the tea’s effects. Because hibiscus lowers blood pressure, drinking the tea alongside antihypertensive drugs may cause blood pressure to drop too low.
Hibiscus tea can also influence blood sugar levels and may enhance the effects of anti-diabetes medications. Combining the tea with drugs intended to lower blood glucose could potentially lead to hypoglycemia. It is also known to interfere with the absorption of certain medications. Consulting a healthcare professional is advisable for anyone with pre-existing conditions or those taking prescription drugs before incorporating hibiscus tea into their daily routine.
Potential Drug Interactions
- Antihypertensive drugs (e.g., ACE inhibitors or ARBs)
- Anti-diabetes medications
- Drugs intended to lower blood glucose
- The anti-malarial drug chloroquine