Hops are the female inflorescences of the plant Humulus lupulus L. They are used primarily in beer brewing to add bitterness and flavor. Hops is also used as an herbal medicine for mood disturbance and insomnia ⁽¹⁾ and to treat menopausal symptoms. In vitro studies suggest hops has antibacterial ⁽²⁸⁾, chemopreventive ^{(2) (3) (4)}, antitumor ⁽⁵⁾, antiangiogenic ⁽⁶⁾, anti-inflammatory ⁽¹⁹⁾, phytoestrogenic ⁽²⁹⁾, and antidiabetic ⁽⁷⁾ properties. In murine models, hops reduced hyperlipidemia ⁽⁸⁾ and obesity ⁽⁹⁾, and protected against bone loss following estrogen depletion ⁽²¹⁾.

In clinical studies, a hops-valerian combination product was reported to improve sleep quality ^(10) (16) and insulin sensitivity in patients with type-2 diabetes ⁽⁷⁾. Other preliminary studies suggest hops extracts may alleviate mild depression, anxiety, and stress ⁽²³⁾ or decrease body fat in healthy subjects ⁽²⁴⁾. Data from an observational study suggest a combination of hops, rosemary extract, and oleanolic acid may help reduce arthritic pain ⁽¹¹⁾. However, it is not clear whether hops alone would exert similar effects.

In postmenopausal women, a few studies suggest hops extracts may alleviate menopausal symptoms ^{(13) (17) (25)} and improve bone health ⁽¹⁸⁾. Some studies also indicate that derivates of hops have phytoestrogenic effects ^(7) (12). Patients with hormone-sensitive cancers should consult their physicians before using products containing hops.