Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
N.E.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 oral contraceptive; ethinyl estradiol and norethindrone suppress gonadotropin (FSH and LH) release, preventing ovulation. Also cause cervical mucus thickening and endometrial changes.
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 orally once daily for 28 days; each tablet contains norethindrone 1 mg and ethinyl estradiol 35 mcg.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Ethinyl estradiol: ~15-19 hours (linear pharmacokinetics); Norethindrone: ~7-9 hours (terminal half-life; steady-state achieved within 5-7 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; undergoes sulfation and glucuronidation. Norethindrone: metabolized in the liver via reduction 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: ~50-60% (metabolites, primarily glucuronide conjugates); Fecal: ~30-40% (biliary excretion of metabolites); Unchanged drug: <5%
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: ~97-98% bound primarily to albumin; Norethindrone: ~96-97% 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: ~2.5-4 L/kg; Norethindrone: ~3.5-5 L/kg; reflects extensive tissue distribution
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); Norethindrone ~65-70% (first-pass metabolism)
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No specific dose adjustment recommended; use with caution in patients with 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 patients with acute hepatitis, severe cirrhosis, or liver tumors (benign or malignant). For Child-Pugh Class C: contraindicated. For Child-Pugh Class A or B: use with caution and monitor liver function.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Postmenarchal adolescents: same as adult dosing (one tablet orally once daily). Safety and efficacy established for use after menarche.
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 postmenopausal women due to lack of need for contraception and potential increased risk of thromboembolism and cardiovascular events.
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 contraceptives. Risk increases with age (>35 years) and heavy smoking (>15 cigarettes/day). Women over 35 who smoke should not use this product.
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),Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate/lipid effects,Ocular lesions (retinal thrombosis),Carcinoma (breast, cervical),Hereditary angioedema,Chloasma,Pregnancy (discontinue if pregnant),Lactation (may reduce milk production)
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,Cerebrovascular or coronary artery disease,Known or suspected breast carcinoma,Endometrial carcinoma or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Pregnancy,Hepatic adenoma or carcinoma,Active liver disease or impaired liver function,Known hypersensitivity to any component,Smoking if age >35 years
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 ethinyl estradiol levels but no dose adjustment needed. High-fat meals do not affect absorption.
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: No increased risk of major birth defects from combined oral contraceptives based on population data; however, inadvertent use is not recommended. Second/third trimester: Avoid use due to potential adverse fetal effects including hormonal disruption. Category X for pregnancy contraindication.
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.
Excreted in breast milk in small amounts (estrogen: M/P ratio ~0.5; progestin data limited). May reduce milk production and quality. Not recommended for nursing mothers. Alternative contraception advised.
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.
No dose adjustments applicable as the drug is contraindicated in pregnancy. Pharmacokinetic changes (e.g., increased clearance of hormones) occur but are not managed with dose changes due to risk.
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.
N. E. E. 1/35 28 is a monophasic combined oral contraceptive containing norethindrone and ethinyl estradiol. Monitor for thromboembolic events, especially in smokers over 35. Efficacy may be reduced with hepatic enzyme inducers. Bleeding irregularities are common in the first 3 cycles.
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, in the order listed on the pack.,Missed pill instructions: if one pill is missed, take it as soon as remembered; if two or more are missed, use back-up contraception for 7 days.,Common side effects include nausea, breast tenderness, and breakthrough bleeding.,Seek immediate medical attention for symptoms of blood clots: leg pain/swelling, sudden chest pain, shortness of breath, or severe headache.,Do not smoke while taking this medication, as smoking increases the risk of serious cardiovascular side effects.,Inform your healthcare provider if you are breastfeeding or have a history of migraines, hypertension, or liver disease.
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 N.E.E. 1/35 28 vs ALTAVERA, answered by our medical review team.
N.E.E. 1/35 28 is a Oral Contraceptive that works by Combination oral contraceptive; ethinyl estradiol and norethindrone suppress gonadotropin (FSH and LH) release, preventing ovulation. Also cause cervical mucus thickening and endometrial changes.. 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 N.E.E. 1/35 28 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 N.E.E. 1/35 28 is: One tablet orally once daily for 28 days; each tablet contains norethindrone 1 mg and ethinyl estradiol 35 mcg.. 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 N.E.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. N.E.E. 1/35 28 is classified as Category C. First trimester: No increased risk of major birth defects from combined oral contraceptives based on population data; however, inadvertent use is not recommended. Second/third trim. 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.