Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORCEPT-E 1/35 28 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 estrogen (ethinyl estradiol) and progestin (norethindrone) contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, and alters endometrial lining.
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,Oral contraceptive
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
1 tablet orally once daily for 21 days, followed by 7 days of placebo tablets.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Norethindrone: 5-14 hours; ethinyl estradiol: 13-27 hours. The terminal half-life of norethindrone is about 10 hours, allowing once-daily dosing; ethinyl estradiol's longer half-life contributes to steady-state concentrations within 3-5 days.
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.
Ethinyl estradiol: primarily metabolized by CYP3A4; norethindrone: primarily metabolized by CYP3A4 and CYP2C9.
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 (primarily as metabolites) and fecal; approximately 50-60% excreted in urine, 30-40% in feces. Ethinyl estradiol and norethindrone are extensively metabolized via hydroxylation and conjugation; glucuronide and sulfate conjugates are eliminated in urine and bile.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Norethindrone: >97% bound to albumin and SHBG; ethinyl estradiol: >97% bound to albumin. Ethinyl estradiol also binds to SHBG with lower affinity.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Norethindrone: approximately 3.5 L/kg; ethinyl estradiol: approximately 2.5 L/kg. These values reflect extensive tissue distribution and binding to tissues such as breast, uterus, and adipose.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: Norethindrone ~64% (first-pass metabolism); ethinyl estradiol ~40-50% (extensive first-pass metabolism). Factors such as food and individual differences may affect bioavailability.
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 acute renal disease or marked renal impairment.
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 or liver tumors (benign or malignant). Use with caution in mild to moderate hepatic impairment; dose adjustment generally not required but monitor for adverse effects.
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. After menarche, use same adult dosing schedule.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
No specific dose adjustment; use with caution due to increased risk of thromboembolic disorders and cardiovascular events in women over 35 who smoke.
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 (thrombosis, stroke, myocardial infarction) from combination oral contraceptives, especially in women over 35 and heavy smokers (>15 cigarettes/day).
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 (DVT, PE, stroke, MI),Hepatic tumors,Hypertension,Gallbladder disease,Carbohydrate/lipid metabolism effects,Ocular lesions (retinal thrombosis),Hereditary angioedema,Chloasma,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 DVT/PE,Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Endometrial cancer or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma,Known or suspected pregnancy,Hypersensitivity to any component
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 does not affect ethinyl estradiol. Avoid St. John's wort (herbal supplement) as it reduces contraceptive efficacy.
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.
First trimester: Increased risk of neural tube defects, cardiovascular malformations, and limb reduction defects if inadvertently exposed to the progestin component (norethindrone) at high doses. Second and third trimesters: No evidence of teratogenicity from estrogen-progestin combinations; however, androgenic effects (pseudohermaphroditism in female fetuses) have been reported with high doses of progestins. Overall, combination oral contraceptives are contraindicated in pregnancy.
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.
Small amounts of ethinyl estradiol and norethindrone are excreted into breast milk (M/P ratio for ethinyl estradiol approximately 0.75; for norethindrone, about 0.66). Use may reduce milk production and quality, especially in early postpartum. Avoid in nursing mothers unless essential; alternative contraception recommended.
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 during pregnancy. No dose adjustments recommended as drug should be stopped immediately upon pregnancy diagnosis.
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.
NORCEPT-E 1/35 28 is a combination oral contraceptive containing ethinyl estradiol 35 mcg and norethindrone 1 mg. It is indicated for contraception and may be used off-label for menstrual disorders. Pearl: Counsel patients that missed pills increase pregnancy risk; refer to prescribing information for missed dose instructions. Monitor for thromboembolic events, especially in smokers over 35. Drug interactions: rifampin, certain anticonvulsants (e.g., phenytoin, carbamazepine), and St. John's wort reduce efficacy. Breakthrough bleeding common in first 3 cycles; if persistent, evaluate for non-compliance or alternative causes.
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 pill daily at the same time, preferably after an evening meal or at bedtime to minimize nausea.,Missed pill? Take as soon as remembered; if >48 hours, use backup contraception (condoms) for 7 days and consult the package insert.,Report immediately: severe leg pain/chest pain/sudden shortness of breath (signs of blood clot), severe headache, vision changes, or jaundice.,Smoking increases risk of serious cardiovascular side effects; avoid smoking especially if over 35.,May decrease efficacy with certain antibiotics (non-rifampin) – use backup contraception during antibiotic course and for 7 days after.,Do not take if pregnant, breastfeeding, or have history of blood clots, stroke, breast cancer, liver disease, or migraine with aura.
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 NORCEPT-E 1/35 28 vs ALTAVERA, answered by our medical review team.
NORCEPT-E 1/35 28 is a Combined Oral Contraceptive that works by Combination estrogen (ethinyl estradiol) and progestin (norethindrone) contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, and alters endometrial lining.. 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 NORCEPT-E 1/35 28 and ALTAVERA depend on the specific clinical indication. These are both Combined Oral Contraceptive agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of NORCEPT-E 1/35 28 is: 1 tablet orally once daily for 21 days, followed by 7 days of placebo tablets.. 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 NORCEPT-E 1/35 28 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. NORCEPT-E 1/35 28 is classified as Category C. First trimester: Increased risk of neural tube defects, cardiovascular malformations, and limb reduction defects if inadvertently exposed to the progestin component (norethindrone). 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.