Some menopausal women experience night sweats and hot flashes. Hormone replacement therapy is the standard of care for menopausal patients, but not all women are good candidates for it and then some simply don't trust science and medicine; they buy organic food, worry about cellphone radiation, and have read Facebook posts claiming hormone replacement therapy puts them at increased risk for breast cancer and cardiovascular disease.

Hops are labeled a natural alternative to medicine because they contain phytoestrogens. Phytoestrogens are plant-based compounds that mimic the action of female sex hormones, whose deficiency is considered to be the root of symptoms often felt by women in menopause.

The concern among the science and health community is that because hops actually do something, but are unregulated by FDA under President Clinton's 1994 DSHEA exemption, what they do could be bad. Compounds in hops may inhibit or deactivate certain drug-metabolizing enzymes and since the half-life in humans is up to 20 hours, the supplements may still be found in the bloodstream when women take medicine. 

Photo: Oregon State University

In a small pilot study, scientists gave 16 research subjects a cocktail of four drugs, each one primarily metabolized by a different enzyme in a family of enzymes known as cytochrome P450s. The drugs were caffeine; alprazolam, an anti-anxiety medicine sold under the trade name Xanax; dextromethorphan, an over-the-counter cough suppressant; and tolbutamide, a medicine used to treat type 2 diabetes. Each trial was done twice. First to see how the women metabolized the drugs normally, and then a hops extract twice daily for two weeks. 

Guidelines for clinical studies of drug interactions involving CYP enzymes have been set by the U.S. Food and Drug Administration, and the hop dietary supplement caused no clinically relevant pharmacokinetic interactions.

So hop supplements may do nothing positive, at least outside placebo effects, but at least they don't seem to produce any harmful drug interactions, at least with respect to the enzymes probed during this investigation.