Products
Red clover is commercially available in the form of capsules, tablets, as a tea and medicinal drug (Trifolii rubri flos), among others. It is mainly marketed as a food supplement.
Stem plant
Red clover belongs to the legume family (Fabaceae). The herb is found in many meadows and fields in this country and is used in agriculture, among other things, for green manuring because the nodule bacteria living symbiotically on the roots fix nitrogen from the air.
Medicinal drug
The dried flower heads, red clover flowers, are used as a medicinal herb. They are called Trifolii rubri flos or Trifolii pratensis flos (Figure).
Ingredients
Red clover contains isoflavones belonging to the so-called phytoestrogens, mainly formononetin and biochanin A, the methyl ethers of daidzein and genistein. The same substances are also found in soy, but not in the same proportions. Soy isoflavones, like red clover, are used to treat menopausal symptoms. The isoflavones have some structural similarity to the female sex hormone estradiol and a similar molecular weight to the hormone. However, they do not have a steroidal structure.
Effects
Red clover phytoestrogens have estrogenic properties. They bind mainly to the estrogen receptor ERβ, but are only weak agonists at ERα. Therefore, they are also referred to as natural SERMs. Although their affinity for the receptor is lower than that of estradiol, they are present in much higher concentrations. Their clinical efficacy for vasomotor symptoms such as hot flashes or other menopausal symptoms is controversial. Positive effects, for example on the cardiovascular system and bone metabolism, cannot be ruled out.
Indications for use
Red clover is used for menopausal symptoms as a kind of natural hormone replacement therapy, also in view of a possible preventive effect against osteoporosis, elevated lipid levels, cardiovascular diseases, cancer and dementia.
Dosage
From the clinical studies conducted, it appears that possible effects appear only after several weeks of regular intake.
Contraindications
- Hypersensitivity
- Pregnancy, lactation, childbearing
- Estrogen-dependent breast cancer
- Endometrial cancer
Full details of contraindications are not available.
Indications for use
Isoflavones are substrates of CYPs and may potentially lead to drug-drug interactions with other agents metabolized via these enzymes.
Adverse effects
Adverse effects in studies conducted included headache, muscle pain, and nausea. Short-term use generally appears to be relatively well tolerated. According to the literature, there are insufficient data on potential adverse effects.
