Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORTREL 7/7/7 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-progestin oral contraceptive. Suppresses gonadotropin release, inhibiting ovulation. Increases cervical mucus viscosity and 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 orally once daily, taken at the same time each day. Each tablet contains norethindrone 0.5 mg/ethinyl estradiol 35 mcg for days 1-7, norethindrone 0.75 mg/ethinyl estradiol 35 mcg for days 8-14, and norethindrone 1 mg/ethinyl estradiol 35 mcg for days 15-21, followed by 7 placebo tablets.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Norelgestromin terminal half-life is approximately 28 hours; ethinyl estradiol terminal half-life is approximately 17 hours. The extended half-life supports once-weekly dosing.
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 first-pass metabolism. Norethindrone: metabolized by reduction and conjugation; primarily via CYP3A4.
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 of metabolites (primarily ethinyl estradiol and norelgestromin conjugates) accounts for approximately 50% of elimination; fecal/biliary excretion accounts for the remainder (about 35-40% fecal, 10-15% biliary).
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Norelgestromin is 99% bound primarily to albumin and sex hormone-binding globulin; ethinyl estradiol is 98% bound primarily to albumin.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Norelgestromin apparent Vd/F is approximately 2.1 L/kg; ethinyl estradiol apparent Vd/F is approximately 5.5 L/kg, indicating extensive tissue distribution.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Transdermal bioavailability of norelgestromin and ethinyl estradiol is approximately 60-65% relative to oral administration due to avoidance of first-pass metabolism.
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dose adjustment recommended for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure due to potential for decreased drug elimination and hormonal alterations.
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 acute hepatic disease or severe hepatic insufficiency (Child-Pugh class C). For Child-Pugh class A or B, use with caution; consider alternative contraception due to possible impaired hormone metabolism. No specific dose adjustment guidelines available.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Safety and efficacy in postmenarchal pediatric patients have been established. Dose is the same as for adults: one tablet orally once daily following the 28-day regimen.
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 studies in geriatric population; use is not appropriate due to lack of need for contraception.
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. Use is contraindicated in women over 35 who 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, myocardial infarction, stroke, hepatic neoplasia, gallbladder disease. Discontinue if jaundice, visual disturbances, or migraine occurs. Blood pressure should be monitored.
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, thromboembolic disorders, cerebral vascular disease, coronary artery disease, known or suspected pregnancy, undiagnosed abnormal genital bleeding, known or suspected breast cancer, liver tumor or active liver disease, hypersensitivity to components, and women over 35 who smoke.
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 exposure but not considered clinically relevant. Avoid herbal supplements such as St. John's wort, which can 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 known association with major congenital anomalies based on population data. However, exposure to ethinyl estradiol and norethindrone acetate is not recommended during pregnancy due to theoretical risks from hormonal exposure. Second and third trimesters: Not indicated for use; hormonal contraceptives should be discontinued if pregnancy occurs. No evidence of fetal harm from inadvertent use early 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.
Combined hormonal contraceptives may reduce milk production and pass into breast milk. The M/P ratio for ethinyl estradiol is approximately 0.3-0.5; for norethindrone, minimal transfer. Use is generally not recommended during breastfeeding, especially in the early postpartum period. 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.
Contraindicated during pregnancy. No pharmacokinetic studies in pregnant women; no dose adjustments needed as drug is discontinued. Standard dosing for non-pregnant women: 7 tablets of 0.035 mg ethinyl estradiol/0.5 mg norethindrone, then 7 tablets of 0.035 mg EE/0.75 mg NE, then 7 tablets of 0.035 mg EE/1 mg NE.
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.
NORTREL 7/7/7 is a triphasic oral contraceptive. The 7/7/7 dosing (7 days of 35 mcg EE/0.5 mg norethindrone, 7 days of 35 mcg EE/0.75 mg norethindrone, 7 days of 35 mcg EE/1 mg norethindrone) mimics natural cycle. Missed dose management: if missed one active pill, take as soon as remembered; if missed two or more, use backup contraception for 7 days and consider emergency contraception. Breakthrough bleeding is common in first 3 cycles. Drug interactions: rifampin, certain anticonvulsants, and some antibiotics may reduce efficacy. Contraindicated in women with migraines with aura, history of DVT/PE, active liver disease, or breast cancer. Monitor blood pressure at baseline and follow-up.
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 each day, following the 7/7/7 sequence.,Missed pill instructions: if you miss one active pill, take it as soon as you remember and continue the pack; if you miss two or more active pills, take the most recent missed pill, discard others, use backup contraception for 7 days, and consider emergency contraception.,Common side effects include nausea, breast tenderness, breakthrough bleeding, and mood changes; these often improve after 3 cycles.,Seek emergency care if you experience leg pain/swelling, chest pain, sudden severe headache, or vision changes, which may signal a blood clot.,Smoking increases the risk of serious cardiovascular side effects, especially if you are over 35 years old.,Tell your doctor about all medications you take, including antibiotics and herbal supplements like St. John's wort.,If you miss a period, take a pregnancy test and contact your doctor.
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 NORTREL 7/7/7 vs ALTAVERA, answered by our medical review team.
NORTREL 7/7/7 is a Oral Contraceptive that works by Combination estrogen-progestin oral contraceptive. Suppresses gonadotropin release, inhibiting ovulation. Increases cervical mucus viscosity and 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 NORTREL 7/7/7 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 NORTREL 7/7/7 is: One tablet orally once daily, taken at the same time each day. Each tablet contains norethindrone 0.5 mg/ethinyl estradiol 35 mcg for days 1-7, norethindrone 0.75 mg/ethinyl estradiol 35 mcg for days 8-14, and norethindrone 1 mg/ethinyl estradiol 35 mcg for days 15-21, followed by 7 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 NORTREL 7/7/7 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. NORTREL 7/7/7 is classified as Category C. First trimester: No known association with major congenital anomalies based on population data. However, exposure to ethinyl estradiol and norethindrone acetate is not recommended . 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.