The researchers propose a Phase II randomized, double-blind, placebo-controlled trial of 180 healthy postmenopausal women experiencing at least 5 hot flashes per day or 35 hot flashes per week. Women will be randomized to one of three arms: 4.5 grams/day (dry weight of extract) of MF101, 9.0 grams/day (dry weight of extract) of MF101 or placebo for 12 weeks.

Inclusion Criteria:

• Women between the ages of 40 to 60.
• Currently receiving medical care from a health care provider.
• Self-report 5 hot flashes per day or 35 hot flashes per week.
• Postmenopausal as defined by 12 months of spontaneous amenorrhea or 6 months of spontaneous amenorrhea with serum FSH levels > 30mlU/ml or 6 weeks post-surgical bilateral oophorectomy with or without hysterectomy or hysterectomy with FSH levels > 30 mlU/ml.
• Agree not to start new herbal or dietary supplements and not to change the dose of any currently used herbal or dietary supplements for the duration of the trial.
• Successful completion of a Hot Flash Diary, a Daily Study Medication Diary and a Bleeding Diary, tolerates placebo, and 80% compliant at run-in.
• Must have had a mammogram within the last 9 months.
• Have access to a phone.
• Provide informed consent.

Exclusion Criteria:

• Inability to sign an informed consent or fill out questionnaires.
• History of breast, uterine or ovarian cancer or melanoma.
• Abnormal mammogram or breast examination within the last 9 months suggestive of cancer.
• Abnormal Pap smear or pelvic examination within the last 9 months suggestive of cancer.
• Double-wall endometrial thickness that exceeds 5 mm measured on transvaginal ultrasound.
• Unexplained abnormal uterine bleeding within six months of enrollment.
• Pregnancy or lactating.
• Clinical evidence of active ischemic cardiovascular disease or a history of cardiovascular disease.
• History of deep vein thrombosis or pulmonary embolism requiring anticoagulation.
• Active liver or gallbladder disease.
• Use of medications, herbal or dietary supplements known to possibly be effective for the treatment of hot flashes within three months of enrollment for oral or transdermal drugs, or within 6 months of enrollment for implanted or injected drugs.
• Use of raloxifene or tamoxifen within three months of enrollment.
• Use of another investigational agent within 3 months of enrollment.
• History of multiple or severe food or medicine allergies.
• Any medical or psychiatric condition that, in the investigator's opinion, would preclude the participant from adhering to the protocol or completing the trial, including severe illness, plans to move, substance abuse, significant problems, or dementia.