Glossary · Treatments

Norethindrone

Also called: Norethisterone, Norethindrone acetate.

Definition: Norethindrone (also called norethisterone) is a 19-nortestosterone-derived progestin used for endometrial protection in HRT (notably as the progestin in the Combipatch and Climara Pro combined patches) and as the progestogen in many oral contraceptives.

Detailed definition

Norethindrone is a synthetic progestin in the 19-nortestosterone family. It binds progesterone receptors with high affinity and has mild residual androgenic activity. It is the progestin component of the Combipatch (estradiol + norethindrone acetate transdermal patch) and Activella (estradiol + norethindrone acetate oral combination). Norethindrone is also used in oral contraceptives. As with other synthetic progestins, the long-term breast cancer profile is less favorable than bioidentical micronized progesterone in observational data.

Why it matters in menopause

Norethindrone is convenient when packaged in a combination patch — one patch containing both estradiol and progestin simplifies dosing for women who want minimal regimen complexity. The trade-off is the synthetic progestin profile vs. bioidentical micronized progesterone.

Sources

External references: Wikipedia.

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