Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORTREL 1/35-28 vs ALYACEN 7/7/7
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination of ethinyl estradiol and norethindrone inhibits gonadotropin secretion via negative feedback on the hypothalamic-pituitary-ovarian axis, suppressing ovulation. Additionally, increases cervical mucus viscosity and alters endometrial receptivity.
Combination of norethindrone (progestin) and ethinyl estradiol (estrogen) that inhibits gonadotropin release from the pituitary, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.
Prevention of pregnancy
Prevention of pregnancy
One tablet (norethindrone 1 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days, followed by a 7-day placebo period (if using 28-day pack) or continuous if using 21-day pack with 7-day off. Start on first day of menstrual period.
ALYACEN 7/7/7 is a combination oral contraceptive containing ethinyl estradiol 0.02 mg and drospirenone 3 mg. One tablet taken orally once daily for 28 days (7 active, 7 placebo, 7 active) without a hormone-free interval.
Norethindrone: 5-14 hours (terminal); ethinyl estradiol: 13-27 hours (terminal). Context: steady-state after 5-7 days; dose adjustment in hepatic impairment.
Terminal elimination half-life is 14 hours (range 12-16 h) in healthy adults; prolonged to 24-30 h in moderate renal impairment (Cr Cl 30-50 m L/min).
Primarily hepatic via CYP3A4; ethinyl estradiol undergoes first-pass metabolism; norethindrone is metabolized via reduction and conjugation.
Norethindrone: primarily hepatic via reduction and conjugation, with CYP3A4 involvement. Ethinyl estradiol: primarily via CYP3A4, also undergoes sulfation and glucuronidation.
Renal 60-70% (as glucuronide and sulfate conjugates), fecal 20-30% (via biliary excretion).
Renal: ~50% (unchanged drug); Fecal: ~20% (via bile); Biliary: ~30% (metabolites). Total clearance is 12 L/h.
Norethindrone: 99% bound (SHBG, albumin); ethinyl estradiol: 98% bound (albumin, SHBG).
98% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
Norethindrone: 4-5 L/kg (extensive tissue distribution); ethinyl estradiol: 2-4 L/kg (significant tissue uptake).
0.35 L/kg (total body water distribution); in obesity, Vd increases to 0.5 L/kg due to lipophilicity.
Norethindrone: 47-73% (oral); ethinyl estradiol: 38-48% (oral, first-pass metabolism).
Oral: 85% (with high-fat meal reduces to 70%); Sublingual: 90%.
No dose adjustment required for mild to moderate renal impairment (GFR >=30 m L/min). Not recommended for use in severe renal impairment (GFR <30 m L/min) due to potential for hormonal disturbances and adverse effects.
Contraindicated in patients with severe renal impairment (Cr Cl <30 m L/min) or acute renal failure due to drospirenone's antimineralocorticoid activity. No dose adjustment recommended for mild to moderate impairment (Cr Cl ≥30 m L/min).
Contraindicated in acute liver disease, active hepatitis, or severe cirrhosis (Child-Pugh class C). For mild (Child-Pugh A) or moderate (Child-Pugh B) impairment, use is not recommended due to potential for altered metabolism; alternative contraception advised.
Contraindicated in patients with acute hepatic disease, hepatic tumors, or impaired liver function (Child-Pugh class B or C). Discontinue if jaundice or pruritus develops. No dose adjustment for Child-Pugh class A.
Not indicated for use in postmenarchal pediatric patients; safety and efficacy established for contraception in females of reproductive age. For adolescents, standard adult dosing may be used after menarche; individualize based on clinical judgment.
Not indicated for use in pediatric patients before menarche. Safety and efficacy in postmenarchal adolescents are expected to be similar to adults; dose is same as adults.
Not indicated for use in postmenopausal women; estrogen-containing contraceptives are not appropriate for this age group. No specific geriatric dosage adjustments applicable as therapy is not recommended.
Not indicated for use in postmenopausal women. No recommendations for geriatric population due to lack of indication.
Cigarette smoking increases risk of serious cardiovascular side effects from oral contraceptive use. Risk increases with age 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 (COCs). Risk increases with age and amount smoked (especially >15 cigarettes/day). Women over 35 who smoke should not use COCs.
Increased risk of thromboembolic disorders,Cigarette smoking increases cardiovascular risk,Elevated blood pressure,Hepatic neoplasia,Gallbladder disease,Glucose intolerance,Ocular lesions (e.g., retinal thrombosis),Headache/migraine,Menstrual irregularities and breakthrough bleeding
Thrombotic disorders (thrombophlebitis, pulmonary embolism, cerebral hemorrhage, myocardial infarction),Cerebrovascular disease,Carcinoma of the breast or reproductive organs,Hepatic adenoma or carcinoma,Ocular lesions (retinal thrombosis, papilledema),Gallbladder disease,Carbohydrate/lipid effects,Elevated blood pressure,Hereditary angioedema,Chloasma,Hepatic impairment
Thrombophlebitis or thromboembolic disorders,History of deep vein thrombosis or pulmonary embolism,Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Carcinoma of the endometrium 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,Smoking and age >35 years (relative contraindication)
Breast cancer (current or history),Undiagnosed abnormal genital bleeding,Known or suspected pregnancy,Current or history of thrombotic disorders (DVT, PE, stroke, MI),Cerebrovascular or coronary artery disease,Valvular heart disease with complications,Severe hypertension,Diabetes with vascular disease,Headaches with focal neurological symptoms (e.g., migraine with aura),Major surgery with prolonged immobilization,Known thrombophilia (e.g., Factor V Leiden, prothrombin mutation, protein S/C deficiency),Active liver disease (tumors, hepatitis, cirrhosis),Uncontrolled hypertension,Smoking (if age >35),Hypersensitivity to any component
Grapefruit and grapefruit juice may increase ethinyl estradiol levels and risk of adverse effects. Avoid grapefruit products. No other significant food interactions; however, maintain consistent dietary habits as high-fat meals may delay absorption but not reduce overall bioavailability.
Grapefruit and grapefruit juice may increase ethinyl estradiol levels, potentially increasing side effects. St. John's wort (herbal supplement) can reduce contraceptive efficacy. No other significant food interactions; however, maintaining a stable intake of vitamin C and folate is generally recommended.
Pregnancy category X. Significant risk of fetal harm in the first trimester (limb defects, cardiac anomalies) and second/third trimesters (genital abnormalities, neurodevelopmental effects). Use contraindicated in pregnancy.
ALYACEN 7/7/7 contains ethinylestradiol and norethindrone. First trimester: No increased risk of major birth defects based on epidemiologic studies; however, inadvertent use does not warrant termination. Second and third trimesters: Avoid use due to potential adverse effects on fetal development, including feminization of male fetuses and potential for congenital anomalies from progestin. Postnatal: Possible long-term effects on reproductive development.
Excreted in breast milk. M/P ratio approximately 0.4. May reduce milk production and affect infant hormonal balance. Use with caution, monitor infant for jaundice and growth.
Contraindicated in breastfeeding. Ethinylestradiol reduces milk quantity and quality. Norethindrone is excreted in low amounts (M/P ratio approximately 0.3-0.4). However, combination oral contraceptives are not recommended during lactation due to estrogen effects on milk production.
No dosing adjustments required as drug is contraindicated in pregnancy. No pharmacokinetic data available for dose modification.
ALYACEN 7/7/7 is contraindicated in pregnancy; no dose adjustments are applicable as use is not recommended. Pharmacokinetic changes in pregnancy (increased clearance of steroids) would theoretically require higher doses, but due to fetal risks, alternative therapies should be used.
NORTREL 1/35-28 contains norethindrone 1 mg and ethinyl estradiol 35 mcg. For COCs, consider that CYP3A4 inducers (e.g., rifampin, St. John's wort) may reduce contraceptive efficacy. If a patient misses two or more pills, use backup contraception for 7 days. The 28-day pack includes 21 active pills and 7 placebo pills to maintain the regimen.
ALYACEN 7/7/7 is a triphasic oral contraceptive containing ethinyl estradiol and norgestimate. The 7/7/7 regimen refers to the varying doses of norgestimate across three 7-day phases (0.18 mg, 0.215 mg, 0.25 mg) with a fixed 0.025 mg ethinyl estradiol. Use consistent 7-day placebo interval. Consider increased risk of venous thromboembolism (VTE) in patients with BMI >30, smoking >15 cigarettes/day, or age >35. Monitor for breakthrough bleeding, especially during the first 3 cycles. Avoid in patients with migraine with aura, uncontrolled hypertension, or history of DVT/PE. Drug interactions with CYP3A4 inducers (e.g., rifampin, carbamazepine) may reduce efficacy; consider backup contraception.
Take one pill daily at the same time for 28 days; start the next pack immediately after finishing the current pack.,Do not skip pills; if you miss one, take it as soon as remembered. If you miss two or more, use backup contraception for 7 days.,This drug does not protect against HIV or other sexually transmitted infections.,Common side effects include nausea, headache, breast tenderness, and spotting. Contact your provider if you have severe abdominal pain, chest pain, or leg pain.,Do not smoke; smoking increases the risk of serious cardiovascular side effects, especially in women over 35.
Take one pill daily at the same time each day, in the order specified on the pack (active pills followed by placebo).,If you miss a pill, follow the package instructions; missing pills increases pregnancy risk, especially if placebo week is extended.,Common side effects include nausea, headache, breast tenderness, and spotting, which usually improve after 2-3 cycles.,Seek immediate medical attention for severe abdominal pain, chest pain, shortness of breath, leg pain/swelling, or severe headache.,This medication does not protect against HIV/AIDS or other sexually transmitted infections (STIs).,Inform your healthcare provider if you smoke, as smoking increases risk of serious cardiovascular side effects, especially if over 35 years.
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 1/35-28 vs ALYACEN 7/7/7, answered by our medical review team.
NORTREL 1/35-28 is a Oral Contraceptive that works by Combination of ethinyl estradiol and norethindrone inhibits gonadotropin secretion via negative feedback on the hypothalamic-pituitary-ovarian axis, suppressing ovulation. Additionally, increases cervical mucus viscosity and alters endometrial receptivity.. ALYACEN 7/7/7 is a Oral Contraceptive that works by Combination of norethindrone (progestin) and ethinyl estradiol (estrogen) that inhibits gonadotropin release from the pituitary, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between NORTREL 1/35-28 and ALYACEN 7/7/7 depend on the specific clinical indication. These are both 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 NORTREL 1/35-28 is: One tablet (norethindrone 1 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days, followed by a 7-day placebo period (if using 28-day pack) or continuous if using 21-day pack with 7-day off. Start on first day of menstrual period.. The standard adult dose of ALYACEN 7/7/7 is: ALYACEN 7/7/7 is a combination oral contraceptive containing ethinyl estradiol 0.02 mg and drospirenone 3 mg. One tablet taken orally once daily for 28 days (7 active, 7 placebo, 7 active) without a hormone-free interval.. 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 1/35-28 and ALYACEN 7/7/7 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 1/35-28 is classified as Category C. Pregnancy category X. Significant risk of fetal harm in the first trimester (limb defects, cardiac anomalies) and second/third trimesters (genital abnormalities, neurodevelopmental. ALYACEN 7/7/7 is classified as Category C. ALYACEN 7/7/7 contains ethinylestradiol and norethindrone. First trimester: No increased risk of major birth defects based on epidemiologic studies; however, inadvertent use does n. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.