Etonogestrel and ethinyl estradiol and Nirmatrelvir and ritonavir interaction
Etonogestrel and ethinyl estradiol and Nirmatrelvir and ritonavir: 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 Etonogestrel and ethinyl estradiol (Etonogestrel/Ethinyl Estradiol) label · effective 2025-02-26
…Etonogestrel/Ethinyl Estradiol Vaginal Ring [see Warnings and Precautions (5.6) and Adverse Reactions (6) ] Use of Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to potential for ALT elevations [see Warnings and Precautions (5.4) and Drug Interactions (7) ] A high risk of arterial or venous thrombotic…
Co-administration with Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir ( 4 )
Risk of Liver Enzyme Elevations with Concomitant Hepatitis C Treatment CHCs, such as Etonogestrel/Ethinyl Estradiol Vaginal Ring, are contraindicated for use with Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir (with or without dasabuvir) [see Contraindications (4) ].
Concomitant Use with HCV Combination Therapy – Liver Enzyme Elevation Do not co-administer Etonogestrel/Ethinyl Estradiol Vaginal Ring with HCV drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to potential for ALT elevations.
…changes in the plasma concentrations of the estrogen and /or progestin have been noted in some cases of co-administration with HIV protease inhibitors (decrease [e.g., nelfinavir, ritonavir, darunavir/ritonavir, (fos)amprenavir/ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir] or increase [e.g., indinavir and atazanavir/ritonavir]) /HCV protease inhibitors…
From the Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Hormonal contraceptive ethinyl estradiol ↓ ethinyl estradiol An additional, non-hormonal method of contraception should be considered during the 5 days of PAXLOVID treatment and until one menstrual cycle after stopping PAXLOVID.
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.