What are the possible side effects of Red Clover (Trifolium pratense)?
A small number of human studies using red clover extracts have all reported good tolerance, without serious side effects after up to one year of treatment. In theory, based on the estrogen-like action of red clover seen in laboratory studies, side effects may include weight gain or breast tenderness, although these have not been reported clearly in humans. In theory, menstrual changes and increased uterus cell growth (endometrial hyperplasia) may also occur, although preliminary short-term studies (less than six months) have found no increases in uterus wall (endometrial) thickness with red clover. Red clover may affect hormonal levels of gonadotropin releasing hormone (GrH), follicle stimulating hormone (FSH), and leutinizing hormone (LH), although early research has not found significant change in FSH or LH levels. In theory, red clover may increase the risk of bleeding. However, there are no reliable human reports of bleeding with red clover. Caution is advised in patients with blee