Background

Herbal supplements are widely used for vasomotor symptoms.

Objective

To test the efficacy of 3 herbal regimens and hormone therapy for relief of vasomotor symptoms compared with placebo.

Design

1-year randomized, double-blind, placebo-controlled trial conducted from May 2001 to September 2004.

Setting

Group Health, Washington State.

Participants

351 women age 45 to 55 years with 2 or more vasomotor symptoms per day; 52% of the women were in menopausal transition and 48% were postmenopausal.

Measurements

Rate and intensity of vasomotor symptoms (1 = mild to 3 = severe), and Wiklund Vasomotor Symptom Subscale.

Interventions

1) Black cohosh, 160 mg daily; 2) multibotanical with black cohosh, 200 mg daily, and 9 other ingredients; 3) multibotanical plus dietary soy counseling; 4) conjugated equine estrogen, 0.625 mg daily, with or without medroxyprogesterone acetate, 2.5 mg daily; or 5) placebo.

Results

Vasomotor symptoms per day, symptom intensity, Wiklund Vasomotor Symptom Subscale score did not differ between the herbal interventions and placebo at 3, 6, or 12 months or for the average over all the follow-up time points (P > 0.05 for all comparisons) with 1 exception: At 12 months, symptom intensity was significantly worse with the multibotanical plus soy intervention than with placebo (P = 0.016). The difference in vasomotor symptoms per day between placebo and any of the herbal treatments at any time point was less than 1 symptom per day; for the average over all the follow-up time points, the difference was less than 0.55 symptom per day. The difference for hormone therapy versus placebo was -4.06 vasomotor symptoms per day for the average over all the follow-up time points (95% CI, -5.93 to -2.19 symptoms per day; P < 0.001).

Limitations

The trial did not simulate the whole-person approach used by naturopathic physicians. Differences between treatment groups smaller than 1.5 Vasomotor symptoms per day cannot be ruled out.

Conclusion

Black cohosh used in isolation, or as part of a multibotanical regimen, shows little potential as an important therapy for relief of vasomotor symptoms.

Clinical trials registration number

NCT00169299.

We designed a randomized double-blind randomized trial to examine the short and long-term effects of alternative approaches commonly used to manage menopause symptoms. Women were randomly assigned to: (1) black cohosh 160 mg daily; (2) multibotanical (50 mg black cohosh, alfalfa, chaste tree, dong quai, false unicorn, licorice, oats, pomegranate, Siberian ginseng, boron) four capsules daily; (3) multibotanical plus telephone counseling to increase dietary soy; (4) conjugated equine estrogen 0.625 mg +/- 2.5 mg medroxyprogesterone acetate; or (5) placebo. Working with a skilled CAM provider helped us choose interventions that reflected naturopathic practices worthy of study. Mass mailing, with careful tracking and rapid responses to recruitment rates, was an effective and cost-effective recruitment strategy. Creativity was necessary to construct methods for blinding capsules and the dietary soy intervention. Independent testing of herbal products was vital to confirming their constituents. The Data and Safety and Monitoring Committee, and project officers at the funding agency, were critical partners in designing responses to unanticipated Women's Health Initiative findings published during the HALT trial. Careful monitoring of adverse events may provide much needed information about side effects of herbal products and supplements. Despite inherent challenges, the study of alternative therapies for menopause symptoms is a rewarding and important area deserving of further inquiry.