Afimoxifene, also known as 4-hydroxytamoxifen (4-OHT) and by its tentative brand name TamoGel, is a selective estrogen receptor modulator (SERM) of the triphenylethylene group and an active metabolite of tamoxifen.

[1][2][3] The drug is under development under the tentative brand name TamoGel as a topical gel for the treatment of hyperplasia of the breast.

[1][4] It has completed a phase II clinical trial for cyclical mastalgia,[5] but further studies are required before afimoxifene can be approved for this indication and marketed.

[6] In addition to its estrogenic and antiestrogenic activity, afimoxifene has been found to act as an antagonist of the estrogen-related receptors (ERRs) ERRβ and ERRγ.

[7][8][9] This drug article relating to the genito-urinary system is a stub.