Typical Dosing Guideline
Standardized commercially prepared isoflavins
4 g PO TID
1 cup PO TID; 4 g flower tops/150 mL water
1.5-3 mL PO TID; 1:1 in 25% alcohol
1-2 mL PO TID; 1:10 in 45% alcohol
Isoflavone extract: 40-160 mg/day PO
Isoflavones: 40-80 mg/day
Specific extract (Promensil): 40 mg/day
Menopausal symptoms and hot flashes, mastalgia, PMS, cancer prevention, indigestion, hypercholesterolemia, whooping cough, asthma, bronchitis, & STD's
Cancer, skin sores, burns, sore eyes, and chronic skin diseases including eczema
- Does not significantly reduce total or LDL cholesterol, OR increase HDL in women 49-65. More studies are needed
- Does not seem to reduce menopausal symptoms
- May decrease nocturnal urinary frequency, international prostate symptom scores, and improve the quality of life
- Does not affect urine flow rate, PSA values, or prostate size
Breast Cancer (prevention)
- May not significantly affect breast cancer risk
- It is not known if has any effect on risk. More studies are needed
- Preliminary evidence suggests reduction in breast pain & tenderness in 45% of patients
- More studies are needed. 40 mg isoflavones qDay did not seem to increase BMD
Serious - Use Alternative
Significant - Monitor Closely
Estrogen-like effects, rash
Cancer (breast, ovarian, uterine), endometriosis, hormone sensitive conditions, uterine fibroids
Coagulation disorders, concurrent CYP3A4 substrates
Pregnancy & Lactation
Pregnancy Category: avoid use
Lactation: avoid use
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Mechanism of Action
Antispasmodic, expectorant constituents
Isoflavones (e.g., daidzein, genistein) are phytoestrogens: weak estrogenic/antiestrogenic properties