Estradiol and norethindrone and Fulvestrant interaction
Estradiol and norethindrone and Fulvestrant: 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 Estradiol and norethindrone (Estradiol / Norethindrone Acetate) label · effective 2026-06-26
Therefore, the relevance of the WHI findings regarding adverse cardiovascular events, dementia and breast cancer to lower CE plus other MPA doses, other routes of administration, or other estrogen plus progestogen products is not known.
Therefore, the relevance of the WHI findings regarding adverse cardiovascular events and dementia to lower CE doses, other routes of administration, or other estrogen-alone products is not known.
Exacerbation of Other Conditions Estrogen therapy, including Estradiol/Norethindrone Acetate Tablets, may cause an exacerbation of asthma, diabetes mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and hepatic hemangiomas.
From the Fulvestrant (CLIGAVYX) label · effective 2026-06-24
Interference of Fulvestrant with Serum Estradiol Immunoassays Due to structural similarity of fulvestrant and estradiol, fulvestrant can interfere with estradiol measurement by immunoassay, resulting in falsely elevated estradiol levels [see Warnings and Precautions (5.4) ] .
Immunoassay Measurement of Serum Estradiol: CLIGAVYX can interfere with estradiol measurement by immunoassay, resulting in falsely elevated estradiol levels.
Immunoassay Measurement of Serum Estradiol Due to structural similarity of fulvestrant and estradiol, fulvestrant can interfere with estradiol measurement by immunoassay, resulting in falsely elevated estradiol levels.
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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.