Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORINYL 1+35 28-DAY vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Norethindrone is a progestogen that suppresses gonadotropin release, inhibiting ovulation; ethinyl estradiol is an estrogen that provides negative feedback on the hypothalamic-pituitary-ovarian axis, further suppressing ovulation and altering cervical mucus and endometrial thickness.
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,Treatment of moderate acne vulgaris in women who desire an oral contraceptive
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet orally once daily for 28 consecutive days (21 active tablets followed by 7 inert tablets).
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Norethindrone: 7-8 hours (terminal half-life); steady state achieved after 5 days. Ethinyl estradiol: biphasic with terminal half-life of 13-27 hours (mean ~17 hours). Clinical context: dosing interval of 24 hours allows stable hormone levels after first cycle.
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 primarily metabolized via reduction and conjugation; ethinyl estradiol is metabolized by CYP3A4 and undergoes conjugation. Both are hepatically eliminated.
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% (conjugates and metabolites), Fecal: 30-40% (biliary elimination of norethindrone and ethinyl estradiol conjugates); total clearance ~4-6 m L/min/kg.
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: 80-85% bound to albumin and SHBG; Ethinyl estradiol: 95-98% bound to albumin (not strongly to SHBG).
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Norethindrone: 2-4 L/kg; Ethinyl estradiol: 2.5-5 L/kg; both indicate extensive tissue distribution.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Norethindrone: 64-67% (oral, first-pass metabolism); Ethinyl estradiol: 38-48% (oral, extensive first-pass conjugation); food does not significantly alter 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. Not studied in severe renal impairment (Cr Cl <30 m L/min); contraindicated in acute renal failure or significant renal disease due to potential fluid retention.
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 Child-Pugh class B and C (moderate to severe hepatic impairment). Use with caution in Child-Pugh class A (mild hepatic impairment) as metabolism may be reduced; 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. For postmenarchal adolescents, dose is same as adults: one tablet orally once daily for 28 days.
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 after menopause. In perimenopausal women, same adult dosing applies; monitor for increased risk of thromboembolism, hypertension, and carbohydrate intolerance.
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 the risk of serious cardiovascular adverse events from combined hormonal contraceptive use. This risk increases with age, especially in women over 35, and with the number of cigarettes smoked. Women who use combined hormonal 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.
Increased risk of thromboembolic disorders; liver disease; hypertension; gallbladder disease; carbohydrate and lipid effects; headache; irregular bleeding; ectopic pregnancy; depression; cervical cancer; hereditary angioedema; chloasma; retinal thrombosis; monitoring of blood pressure, glucose, lipids, liver function.
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; undiagnosed abnormal genital bleeding; pregnancy; liver tumors or active liver disease; known hypersensitivity; concomitant use with hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir with or without dasabuvir.
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 increase estrogen levels; advise limited consumption. Take with food to reduce gastrointestinal upset. Avoid St. John's Wort as it may reduce 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: No increased risk of major birth defects from inadvertent exposure. Second and third trimesters: Avoid use due to risk of fetal harm from estrogen/progestin exposure; association with placental abruption, fetal growth restriction, and preterm delivery.
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; M/P ratio not established for norethindrone/ethinyl estradiol combination. Use with caution; may reduce milk production. Consider alternative contraception during breastfeeding.
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 in pregnancy; no dose adjustments recommended as use is not advised. Pharmacokinetic changes (increased clearance, volume of distribution) are relevant only if inadvertent exposure occurs, but no dose adjustment is standard.
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.
Norinyl 1+35 (norethindrone 1 mg/ethinyl estradiol 35 mcg) is a monophasic combined oral contraceptive. Missed pill management: if one active pill missed, take as soon as remembered; if two missed in week 1 or 2, take two pills on day remembered and two on next day; if two missed in week 3 or three missed at any time, discard remainder of pack and start new pack next day. Use backup contraception for 7 days after any miss. Advise to take at same time daily to maintain consistent hormone levels. Monitor for thromboembolic events; absolute contraindication if history of DVT/PE or migraine with aura. Prescribe with caution in smokers over 35 years old.
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, preferably after the evening meal to reduce nausea.,Start the first pill on the first day of menstrual period for immediate contraceptive protection.,If you miss a pill, refer to the package insert or call your healthcare provider.,Use a back-up contraceptive method (e.g., condoms) for the first 7 days if starting after day 5 of your cycle.,Common side effects include nausea, breast tenderness, and breakthrough bleeding, which often improve after 3 months.,Seek medical attention for severe abdominal pain, chest pain, leg swelling, or severe headache.,Do not smoke while taking this medication, especially if over 35 years old, due to increased risk of blood clots.,This medication does not protect against HIV or other sexually transmitted infections.
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 NORINYL 1+35 28-DAY vs ALTAVERA, answered by our medical review team.
NORINYL 1+35 28-DAY is a Combined Oral Contraceptive that works by Norethindrone is a progestogen that suppresses gonadotropin release, inhibiting ovulation; ethinyl estradiol is an estrogen that provides negative feedback on the hypothalamic-pituitary-ovarian axis, further suppressing ovulation and altering cervical mucus and endometrial thickness.. 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 NORINYL 1+35 28-DAY 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 NORINYL 1+35 28-DAY is: One tablet orally once daily for 28 consecutive days (21 active tablets followed by 7 inert 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 NORINYL 1+35 28-DAY 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. NORINYL 1+35 28-DAY is classified as Category C. First trimester: No increased risk of major birth defects from inadvertent exposure. Second and third trimesters: Avoid use due to risk of fetal harm from estrogen/progestin exposu. 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.