Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FEMCON FE vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination oral contraceptive containing norethindrone and ethinyl estradiol. Inhibits ovulation via suppression of gonadotropins (FSH, LH); increases cervical mucus viscosity, impairing sperm penetration; alters endometrial receptivity.
Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
Prevention of pregnancy
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet (norethindrone 0.5 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
The terminal elimination half-life of ethinyl estradiol is 13-18 hours; for norethindrone, it is 7-12 hours. Both allow once-daily dosing for contraceptive efficacy.
Levonorgestrel: terminal elimination half-life 25±10 hours; ethinyl estradiol: 13±7 hours. Clinical context: steady-state concentrations achieved within 5-7 days; contraceptive efficacy requires consistent daily dosing.
Norethindrone is metabolized primarily via reduction and sulfate conjugation; ethinyl estradiol is metabolized via CYP3A4 and glucuronidation.
Ethinyl estradiol: primarily metabolized by CYP3A4; undergoes sulfation and glucuronidation. Desogestrel: rapidly converted to active metabolite etonogestrel via CYP2C9 and CYP2C19; further metabolism by CYP3A4.
Renal excretion accounts for approximately 40-60% of the dose as metabolites; fecal excretion is about 20-30% via bile. Unchanged drug excretion is minimal.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Ethinyl estradiol is approximately 98% bound to albumin and sex hormone-binding globulin (SHBG); norethindrone is about 80% bound to albumin and SHBG.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Ethinyl estradiol: 2.3-4.1 L/kg; norethindrone: 3.6-4.5 L/kg. Indicates extensive tissue distribution, including reproductive tissues.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral bioavailability: ethinyl estradiol ~40-45% (due to first-pass metabolism); norethindrone ~60-80%. Ferrous fumarate (iron supplement) has low bioavailability but is not relevant for contraception.
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment due to potential estrogen accumulation.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal disease or acute renal failure due to potential fluid retention.
Contraindicated in severe hepatic disease (Child-Pugh class C). Use with caution in Child-Pugh class A or B; consider alternative contraception.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily).
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
Not indicated for use in postmenopausal women. No dose adjustment required for healthy elderly; consider risks of thromboembolism and metabolic effects.
Not indicated for postmenopausal women. No specific geriatric dosing; consider increased risk of thromboembolism, cardiovascular disease, and metabolic effects in older women of reproductive age.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (>35 years) and number of cigarettes smoked. Women who use combination oral contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events from combined oral contraceptives. Risk increases with age (especially >35 years) and with number of cigarettes smoked. Women who use combined hormonal contraceptives should be strongly advised not to smoke.
Thrombotic disorders (venous thromboembolism, stroke, MI),Cardiovascular disease (especially in smokers >35 years),Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate/lipid effects,Headache/migraine,Uterine bleeding irregularities,Ocular effects (retinal thrombosis),Depression
Thrombotic disorders: risk of venous thromboembolism (VTE), stroke, myocardial infarction; discontinue if thrombotic event occurs.,Hepatic disease: discontinue if jaundice or liver function abnormalities develop.,Hypertension: monitor blood pressure; discontinue if uncontrolled.,Carbohydrate metabolism: may affect glucose tolerance; monitor diabetic patients.,Depression: discontinue if significant depression occurs.,Gallbladder disease: increased risk of cholelithiasis.
Thrombophlebitis or thromboembolic disorders,History of deep vein thrombosis or pulmonary embolism,Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Undiagnosed abnormal genital bleeding,Known or suspected pregnancy,Benign or malignant liver tumor,Active liver disease or impaired liver function,Hypersensitivity to any component,>35 years and smokes ≥15 cigarettes per day
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast carcinoma,Estrogen-dependent neoplasia (known or suspected),Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma (known or suspected),Pregnancy (known or suspected),Hypersensitivity to any component
No significant food interactions. Grapefruit juice may slightly increase estrogen levels but not clinically relevant. Avoid excessive alcohol as it may increase liver enzymes and alter hormone metabolism.
No significant food interactions. Alcohol does not affect efficacy but may increase risk of adverse effects such as nausea. Grapefruit juice has no known interaction. Avoid excessive alcohol consumption due to potential hepatotoxicity.
FDA Pregnancy Category X. Contraindicated in pregnancy due to known teratogenicity. First trimester exposure is associated with cardiovascular defects, neural tube defects, and limb reduction defects. Second and third trimester exposure carries risks of fetal genital abnormalities (e.g., virilization of female fetuses from progestin component).
ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular defects (relative risk 1.2-1.4) and no consistent increase in other major malformations. Second and third trimesters: No known teratogenic effects, but theoretical risks from estrogenic effects (e.g., feminization of male fetus). Postnatal: No increased risk of long-term developmental effects from pregnancy exposure.
Contraindicated in breastfeeding. Excreted in breast milk; may suppress milk production and cause adverse effects in nursing infants (e.g., jaundice, breast enlargement). M/P ratio not established; ethinyl estradiol and norethindrone acetate are present in low levels. Use alternative contraception.
Combined oral contraceptives may reduce milk production and quality, especially in early lactation. Ethinyl estradiol transfers into breast milk at low levels (M/P ratio approximately 0.1-0.2), excluding clinical effects in term infants. Levonorgestrel transfer is minimal (M/P ratio ~0.2-0.4). Use is generally avoided in breastfeeding women, especially during the first 6 weeks postpartum. Progestin-only methods are preferred.
Contraindicated; no dosing adjustments are applicable as drug should be discontinued immediately if pregnancy occurs. No pharmacokinetic studies in pregnancy; use not recommended.
Contraindicated in pregnancy. No dose adjustment recommended because use is discontinued upon confirmed or suspected pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased hepatic clearance, altered binding proteins) are not relevant for this indication.
Monitor for thromboembolic events. Counsel on the importance of consistent daily dosing. Advise that withdrawal bleeding may be absent or lighter. Contraindicated in breastfeeding within 21 days postpartum due to estrogen effects. Use with caution in migraine with aura.
ALTAVERA is a combined oral contraceptive (COC) containing ethinylestradiol and levonorgestrel. It inhibits ovulation via suppression of gonadotropins. Counsel patients to take at the same time daily to maintain efficacy. Missed pill management: if missed within 12 hours, take immediately; if >12 hours, take last missed pill and use backup contraception for 7 days. Be aware of increased VTE risk, especially in smokers over 35. May reduce effectiveness of lamotrigine; monitor seizure control. Initiate on the first day of menses or first Sunday after onset.
Take one tablet daily at the same time each day.,If you miss a pill, follow the instructions in the package insert or ask your healthcare provider.,Femcon Fe may cause nausea; taking with food can reduce this.,Bleeding may be irregular initially; consistent use improves cycle control.,This medication does not protect against HIV or other STDs.
Take one tablet daily at the same time each day, with or without food.,If you miss a pill by less than 12 hours, take it as soon as you remember. If more than 12 hours, take the missed pill and use a backup method (e.g., condoms) for the next 7 days.,Smoking increases your risk of serious cardiovascular side effects, especially if you are over 35 years old. Do not smoke while taking this medication.,Seek immediate medical attention if you experience sudden severe headache, chest pain, leg pain/swelling, or vision changes (symptoms of blood clots).,This medication does not protect against HIV or other sexually transmitted infections.,If you are taking lamotrigine or other anticonvulsants, tell your doctor; your seizure medication may be less effective.,Store at room temperature away from moisture and heat.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about FEMCON FE vs ALTAVERA, answered by our medical review team.
FEMCON FE is a Oral Contraceptive that works by Combination oral contraceptive containing norethindrone and ethinyl estradiol. Inhibits ovulation via suppression of gonadotropins (FSH, LH); increases cervical mucus viscosity, impairing sperm penetration; alters endometrial receptivity.. ALTAVERA is a Combined Oral Contraceptive that works by Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FEMCON FE and ALTAVERA depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of FEMCON FE is: One tablet (norethindrone 0.5 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days.. The standard adult dose of ALTAVERA is: 1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between FEMCON FE and ALTAVERA in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. FEMCON FE is classified as Category C. FDA Pregnancy Category X. Contraindicated in pregnancy due to known teratogenicity. First trimester exposure is associated with cardiovascular defects, neural tube defects, and lim. ALTAVERA is classified as Category C. ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular def. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.