Various doses of red clover isoflavones have been used to treat conditions. For instance, for benign prostatic hypertrophy (enlarged prostate), a dose of 40 milligrams of red clover isoflavones per day (Trinovin®) has been studied. For breast cancer prevention, a red clover-derived isoflavone tablet containing 26 milligrams biochanin A, 16 milligrams formononetin, 1 milligram genistein, and 0.5 milligram of daidzein has been studied.
For cardiovascular disease, a dose of 86 milligrams per day for one month has been studied. For diabetes, 50 milligrams and 86 milligrams per day of red clover isoflavones per day have been studied for diabetic complications. For high cholesterol, 28-86 milligrams of red clover isoflavones per day (Rimostil®), or 80 milligrams of red clover isoflavones per day (Promensil®), have been studied. For hormone replacement, a dose of 40-160 milligrams of red clover isoflavones per day (Promensil®) has been studied. Rimostil® (57 milligrams of red clover) has also been used. For osteoporosis, a dose of 40 milligrams of red clover isoflavones per day (Promensil®) has been studied.
There is not enough scientific evidence to recommend use of red clover in children.
People with known allergies or reactions to products containing red clover or isoflavones should avoid taking red clover.
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 bleeding disorders, taking drugs that may increase the risk of bleeding, or scheduled for surgery. Dosing adjustments may be necessary.
Red clover has been studied for lowering blood sugar with inconclusive results. Caution is warranted until further research is available.