Conjugated estrogens and Medroxyprogesterone interaction
Conjugated estrogens and Medroxyprogesterone: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Conjugated estrogens (Premarin) label · effective 2025-05-30
…Cardiovascular disorders and Probable Dementia .) The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism (PE), stroke and myocardial infarction (MI) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral CE (0.625 mg) combined with medroxyprogesterone acetate (MPA) [2.5 mg], relative to placebo.
Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer.
Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.
Estrogen Plus Progestin Therapy Cardiovascular Disorders and Probable Dementia Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia.
(See CLINICAL STUDIES and WARNINGS, Cardiovascular disorders .) The WHIMS estrogen plus progestin ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily CE (0.625 mg) combined with MPA (2.5 mg), relative to placebo.
From the Medroxyprogesterone (medroxyprogesterone acetate) label · effective 2026-02-23
Loss of Bone Mineral Density Use of MPA Injectable Suspension, USP reduces serum estrogen levels and is associated with significant loss of bone mineral density (BMD).
Cancer Risks Breast Cancer Women who have or have had a history of breast cancer should not use hormonal contraceptives, including MPA Injectable Suspension, USP, because breast cancer may be hormonally sensitive [see Contraindications (4) ].
Monitoring A woman who is taking hormonal contraceptive should have a yearly visit with her healthcare professional for a blood pressure check and for other indicated healthcare.
Drugs or herbal products that induce such enzymes may decrease the plasma concentrations of contraceptive hormones, and may decrease the effectiveness of hormonal contraceptives.
Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include: • barbiturates • bosentan • carbamazepine • felbamate • griseofulvin • oxcarbazepine • phenytoin • rifampin • St.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.