Herbal Medicines for Menopausal Symptoms? Hang Onto Your Wallet and Your Health

Want to use red clover or ginseng to alleviate some of your menopausal symptoms? A highly respected British medical journal advises otherwise.

The January 2009 Drug and Therapeutics Bulletin reviewed these and other herbal and dietary supplements that are used to treat the symptoms of menopause. The journal found that women should not use these supplements to ease the symptoms of menopause because the products are not effective and many can cause dangerous side effects. The products also have the potential to interact dangerously with other drugs or herbal supplements.

In recent years, the tendency for women to use these dietary and herbal supplements has greatly accelerated with the evidence that more "traditional" hormone replacement therapies — estrogens or estrogens plus progestagens (such as PREMARIN or PREMPRO) — have been found, with longer term use, to increase the risk of breast cancer, ovarian cancer, venous thromboembolism (blood clots in the legs that can break off and go to the lungs), heart attacks and strokes, as well as other diseases.

In Britain, one survey suggested that about 40 percent of women who are going through menopause have used herbal or other alternative treatments for relieving menopausal symptoms such as hot flashes and night sweats.

The herbal products are easily available on the Internet and in a wide variety of stores; many women who use them do not even think to tell their doctors that they’re using the supplements because they don’t think of them as "real drugs". And the fact that they are "natural" leads many to believe the products are safe. But these products can have serious health consequences.

The following is based on the DTB article and reviews from Worst Pills, Best Pills (Black Cohosh and ginseng). In our previous reviews and in examining the results in the DTB article, we have only reported the results of efficacy studies in which just one herb, rather than combinations, were used so as to make the results more interpretable. We have also limited our review to randomized, placebo-controlled clinical trials.

The Drug and Therapeutics Bulletin reviewed the following commonly used products for menopausal symptoms for effectiveness and safety:

• Black cohosh

• Red clover

• Dong quai/dang gui

• Evening primrose oil

• Ginseng

Black Cohosh

Black cohosh is a North American plant. The root and rootstalk are used for medical purposes.

Effectiveness

The bulletin reviewed seven randomized, placebo-controlled trials of black cohosh and found that, in four of those, there was no evidence that the herb was superior to a placebo.

Public Citizen has previously described the results of the largest and apparently most well-conducted of these studies (Worst Pills, Best Pills News, March 2007). Those authors concluded that "black cohosh used in isolation, or as part of a multibotanical regimen, shows little potential as an important therapy for relief of vasomotor symptoms [change of the size of blood vessels responsible for hot flashes]."

In two other randomized trials, black cohosh was found to be similarly effective to estrogen drugs in relieving menopausal symptoms and, in another placebo-controlled study, it was found more effective than the placebo. However, in all of the three latter trials, there were serious methodological problems that cast doubt on the results.

Safety Concerns

Short-term post-marketing studies of black cohosh have revealed that mild, short-lasting side effects such as headache, dizziness and gastrointestinal complaints have been reported, although the rates of unwanted side effects with black cohosh in randomized controlled trials were similar to those with a placebo.

Worst Pills, Best Pills News previously has noted (Worst Pills, Best Pills News, August 2006) that the Australian equivalent of the U.S. Food and Drug Administration (FDA) reported 49 cases of liver toxicity worldwide associated with the use of black cohosh. Of these 49 suspected cases of liver toxicity, five patients experienced liver failure, and four of those cases required a liver transplant.

Serious cases of liver toxicity have occurred when patients have used the supplement for less than a month. Because of this, patients should stop using the product and consult their doctor if they develop symptoms and signs suggestive of liver toxicity. This includes symptoms such as yellowing of the skin and eyes, severe upper stomach pain with nausea and vomiting and loss of appetite.

Red Clover 

Red clover contains isoflavones, a class of phytoestrogens which have estrogen-like activity.

Effectiveness

A meta-analysis of five randomized trials lasting at least 12 weeks examined the efficacy of foods and supplements including high levels of phytoestrogens (red clover extracts) for reducing hot flashes and night sweats in menopausal women; however, this analysis found no difference in the frequency of hot flashes between women using red clover extract and those using a placebo.

The reviewers concluded that there was no evidence that phytoestrogens treatments helped to relieve menopausal symptoms.

Safety Concerns

Red clover appears to be well-tolerated with few, if any, serious side effects found in clinical studies.

But because red clover contains isoflavones, the question of safety in hormone-sensitive tissue such as breast and uterus is important. However, its safety in women with a history of hormone-sensitive cancers or other hormone-sensitive conditions is currently unknown.

There is some evidence that phytoestrogen supplements can interfere with drugs that affect estrogen receptors (such as tamoxifen, brand name NOLVADEX) and may reduce the effects of aromatize inhibitor drugs such as letrozole (FEMARA).

Dong Quai/Dang Gui

The root of this plant, sometimes in combination with other herbs, has been used for hundreds of years as part of traditional Chinese medicine to treat many medical problems, including menopausal symptoms.

Effectiveness

In a 24-week double-blind randomized trial involving 71 women with frequent and troublesome night sweats or hot flashes, researchers found no difference between those on dong quai and those on placebo.

Safety Concerns

Sensitivity to the sun and skin side effects (photosensitivity) have been observed in some people using dong quai who have also been exposed to the sun.

Even more serious is the evidence that dong quai can increase the risk of bleeding in people who are also using the blood thinner warfarin (COUMADIN) by accentuating the blood-thinning effects of warfarin. Because of this, it is too dangerous to use this herb if you are using warfarin.

Evening Primrose Oil

Evening primrose oil is extracted from the seeds of the evening primrose plant, a native American wildflower. Although the oil is rich in the fatty acids linoleic acid and gamma linolenic acid, there is no biologically plausible reason why these components should improve menopausal symptoms.

Effectiveness

In one randomized placebo-controlled trial involving 56 menopausal women, researchers found that the reduction in hot flashes was no different with evening primrose oil than it was in women using a placebo. In addition, no other benefits were seen.

Safety Concerns

According to the Drug and Therapeutics Bulletin review, when given with drugs that can cause seizures, such as some anti-psychotic medicines, evening primrose oil may further increase the risk of seizures.

Ginseng

Effectiveness

One 16-week double-blind randomized placebo-controlled trial involving 384 postmenopausal women compared ginseng with a placebo and found that the Psychological General Well-Being Index scores (the primary outcome measure) did not differ between the treatment groups.

Safety Concerns

In our WorstPills.org review of ginseng, we state that "ginseng has been associated with hypertension, nervousness, insomnia, vomiting, headache, skin rashes and nosebleeds. A ginseng abuse syndrome, involving the simultaneous use of caffeine, has also been described. Its features are hypertension, nervousness, and sleeplessness.

Other reports describe estrogen-like effects for ginseng: changes in the lining of the vagina and vaginal bleeding."

According to the FDA, ginseng "can interfere with the bleeding effects of COUMADIN [warfarin]. In addition, ginseng can enhance the bleeding effects of heparin, aspirin, and nonsteroidal anti-inflammatory drugs such as ibuprofen, naproxen, and ketoprofen. Combining ginseng with MAO inhibitors such as NARDIL [phenelzine] or PARNATE [tranylcypromine] may cause headache, trouble sleeping, nervousness, and hyperactivity."

What You Can Do

There is no convincing evidence that any of the herbal supplements promoted for relief of menopausal symptoms is beneficial. In addition, as discussed above, many of them have serious safety problems. Given the lack of benefit, why would a woman want to risk her health for a product — usually an expensive one — that jeopardizes her health?