Duavee is Back on the Market

What you need to know about this underused option for menopausal hormone therapy

Duavee is an estrogen mixed with a type of medication called a selective estrogen receptor modulator or SERM and it is indicated for hot flashes and night sweats as well as prevention of osteoporosis. However, the manufacturer voluntarily pulled it off the market in 2020 due to some issues with the packaging that affected the stability of the drug and then…well, nothing. But on June 5th, Pfizer announced that it was back in stock.

If you’ve never heard of Duavee (and with a three year absence from the market, that is totally understandable) or one of its components, bazedoxifene, that’s okay, I’m going to get you up to speed. 

Traditional menopausal hormone therapy for someone with a uterus is estrogen plus a progesterone or progestin. Estrogen stimulates the endometrium (lining of the uterus) and the hormone progesterone or progestin (a synthetic progesterone) counteracts that effect. Without progesterone or a progestin, the risk of abnormal bleeding and cancer of the lining of the uterus from estrogen is high (read more about that risk in this previous post).

But progesterone/progestins aren’t the only game in town when it comes to blocking the effect of estrogen on the uterus. Enter the selective estrogen receptor modulators or SERMs. These are medications that sometimes act like an estrogen, but sometimes block the effect of estrogen and they were originally designed for treating breast cancer. Think of a hormone receptor as a lock and the hormone a key. The lock must be turned by the key for the hormone to have an effect on the cell. A SERM is like a key that has been cut a little differently, so on some tissues it works just like an estrogen and turns the lock, and on other tissues it fits into the lock, but jams it, so not only does the lock not turn, but now if estrogen comes along the lock is out of service.