Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ORTHO-NOVUM 7/14-28 vs ALYACEN 1/35
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 containing ethinyl estradiol and norethindrone. Suppresses gonadotropin release (FSH, LH) via negative feedback, inhibiting ovulation. Also increases cervical mucus viscosity and alters endometrial receptivity.
Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on hypothalamic-pituitary axis; norethindrone induces progestational effects including cervical mucus thickening and endometrial changes, inhibiting ovulation and sperm penetration.
Prevention of pregnancy,Treatment of moderate acne vulgaris in women ≥15 years of age who have no known contraindications and have achieved menarche,Off-label: menstrual cycle regulation, dysmenorrhea, endometriosis-associated pain
Prevention of pregnancy
One tablet daily for 28 days; each tablet contains norethindrone 0.5 mg and ethinyl estradiol 0.035 mg (days 1-7), norethindrone 0.75 mg and ethinyl estradiol 0.035 mg (days 8-14), norethindrone 1 mg and ethinyl estradiol 0.035 mg (days 15-21), and placebo (days 22-28). Take at same time each day.
One tablet (norethindrone 1 mg and ethinyl estradiol 35 mcg) orally once daily for 21 consecutive days, followed by 7 days of placebo or no tablets.
Ethinyl estradiol: ~13-27 h (mean 17 h); Norethindrone: ~5-14 h (mean 8 h). Clinical context: steady-state achieved after ~5 days; half-life supports daily dosing.
Norethindrone: 8-11 hours (terminal); ethinyl estradiol: 10-20 hours (terminal). The half-life supports once-daily dosing for oral contraceptive efficacy.
Ethinyl estradiol: primarily metabolized via CYP3A4, undergoes first-pass metabolism and enterohepatic circulation. Norethindrone: reduced to metabolites, conjugated (glucuronidation and sulfation), and excreted in urine and feces.
Ethinyl estradiol: primarily hepatic via CYP3A4; norethindrone: hepatic reduction and sulfate conjugation.
Renal: ~50-60% (metabolites); biliary/fecal: ~30-40% (metabolites); unchanged drug <1% in urine.
Renal excretion of metabolites (primarily ethinyl estradiol and norethindrone conjugates) accounts for approximately 50-60% of elimination; fecal excretion accounts for 30-40%. Unchanged drug excretion is minimal (<5%).
Ethinyl estradiol: 97-98% bound to serum albumin; Norethindrone: 97-99% bound to albumin (major) and SHBG (minor).
Norethindrone: 61% bound to albumin and SHBG; ethinyl estradiol: 97-98% bound to albumin.
Ethinyl estradiol: 2.3-4.2 L/kg (mean 3.5 L/kg); Norethindrone: 2.5-5.0 L/kg (mean 3.8 L/kg). Clinical meaning: extensive distribution into tissues, including reproductive organs.
Norethindrone: 3.8-4.5 L/kg; ethinyl estradiol: 2.0-4.0 L/kg. Large Vd indicates extensive tissue distribution.
Oral: Ethinyl estradiol ~40-48% (first-pass metabolism); Norethindrone ~50-70% (first-pass metabolism). Food may slightly increase bioavailability.
Oral: Norethindrone ~64%, ethinyl estradiol ~38-48% (due to first-pass metabolism).
No specific dose adjustment recommended in published literature; however, use with caution in patients with severe renal impairment (e GFR <30 m L/min) due to potential fluid retention and electrolyte disturbances. No data for specific GFR-based modifications.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure due to potential fluid retention and electrolyte disturbances.
Contraindicated in patients with severe hepatic disease (Child-Pugh class C) or hepatic tumors. For Child-Pugh class A or B, use with caution; no specific dose adjustment guidelines exist. Discontinue if jaundice or signs of hepatic dysfunction develop.
Contraindicated in patients with hepatic impairment, including Child-Pugh class B or C, due to impaired metabolism of estrogen and progestin. Not recommended in patients with active liver disease or history of liver tumors.
Not indicated for use before menarche. For post-menarcheal adolescents, same dosing as adults: one tablet daily for 28 days. Use only after appropriate evaluation and counseling.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults. Safety and efficacy established for contraception; weight-based dosing not applicable.
Not indicated for use in postmenopausal women. Elderly-specific dosing not applicable.
Not indicated for use after menopause due to lack of benefit and increased risks (e.g., cardiovascular, thromboembolic events). If used, monitor for fluid retention, hypertension, and glucose intolerance.
Cigarette smoking increases risk of serious cardiovascular events. 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 and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
Increased risk of thromboembolic disorders (DVT, PE, stroke, MI),Cigarette smoking increases cardiovascular risk,Increased risk of cervical cancer (HPV-related),Hepatic neoplasia (benign/malignant) associated with long-term use,Exacerbation of migraine,Depression,Gallbladder disease,Impaired glucose tolerance,Elevated blood pressure,Hereditary angioedema
Thrombotic disorders (e.g., DVT, PE, stroke, MI),Cerebrovascular disease,Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate and lipid effects,Ocular lesions,Hereditary angioedema,Chloasma,Menstrual irregularities,Pregnancy exclusion prior to initiation
Known or suspected pregnancy,Current or past history of thromboembolic disorders (e.g., DVT, PE),Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Active liver disease or benign/malignant liver tumors,Undiagnosed abnormal genital bleeding,Hypersensitivity to any component,Age >35 and smoking cigarettes,Uncontrolled hypertension,Diabetes with vascular involvement,Migraine with focal aura at any age,Major surgery with prolonged immobilization
Venous or arterial thrombotic/thromboembolic disease (current or history),Cerebrovascular disease,Coronary artery disease,Known or suspected breast cancer,Endometrial 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 in women over 35
Grapefruit juice may increase ethinyl estradiol levels and risk of adverse effects; consider avoiding. No other significant food interactions.
No significant food interactions. Grapefruit juice may increase estrogen levels, but clinically not a concern. Avoid excessive alcohol, which may impair liver function and increase estrogen exposure. Maintain a healthy diet, as weight gain is possible.
First trimester: Post-marketing studies have not shown an increased risk of birth defects with combined oral contraceptives. However, inadvertent use during early pregnancy is not associated with teratogenicity. Second and third trimesters: Use is contraindicated due to potential adverse effects on fetal development, including estrogenic effects on female fetuses and androgenic effects on male fetuses. There is a risk of fetal genital abnormalities if exposed in utero, though absolute risk is low. Overall, category X designation for use during pregnancy.
Pregnancy category X. Use of ALYACEN 1/35 (norethindrone/ethinyl estradiol) is contraindicated during pregnancy. First trimester: Increased risk of congenital anomalies, including cardiovascular defects and limb reduction defects. Second/third trimesters: Potential for urogenital abnormalities and feminization of male fetus. Exposure is associated with subsequent development of clear cell adenocarcinoma of vagina/cervix in female offspring (DES-related).
Combined oral contraceptives, including Ortho-Novum, are generally not recommended during breastfeeding, especially in the early postpartum period, due to estrogen-induced reduction in milk production and quality. Small amounts of ethinylestradiol and norethindrone are excreted in breast milk. M/P ratio for ethinylestradiol is approximately 0.15–0.3; for norethindrone, approximately 0.5–1.2. Progestin-only methods are preferred. Use only when no alternative and with caution.
Small amounts of contraceptive steroids and/or metabolites have been identified in breast milk. M/P ratio: Not specifically determined for this combination; ethinyl estradiol M/P ratio ~0.02-0.04. Use may reduce milk production and quality. Breastfeeding not recommended during use. Alternative contraception advised.
Ortho-Novum is contraindicated in pregnancy. No dose adjustments are recommended because use during pregnancy is not indicated. Pharmacokinetic changes in pregnancy (e.g., increased volume of distribution, altered hepatic metabolism) would theoretically require dose modifications, but since the drug is contraindicated, no adjustment is applicable.
Contraindicated in pregnancy; no dose adjustments applicable. Discontinue medication immediately upon pregnancy detection.
ORTHO-NOVUM 7/14-28 is a triphasic oral contraceptive with variable doses of norethindrone and ethinyl estradiol. Bleeding irregularities are common, especially in the first few cycles; reassure patients if pregnancy is ruled out. Missed pills increase risk of breakthrough ovulation; refer to package instructions for missed doses. Concomitant use of CYP3A4 inducers (e.g., rifampin, certain anticonvulsants) may reduce contraceptive efficacy.
ALYACEN 1/35 is a combination oral contraceptive containing ethinyl estradiol 35 mcg and norgestimate 1 mg. It is indicated for the prevention of pregnancy and for the treatment of moderate acne vulgaris in females ≥15 years of age who desire an oral contraceptive. Monitor for thromboembolic events, especially in smokers over 35 or those with migraine with aura. Use with caution in patients with liver impairment or history of cholestatic jaundice. The pill-free interval should not exceed 7 days; missed pills increase ovulation risk. Consider non-hormonal backup if vomiting or diarrhea occurs within 4 hours of dosing.
Take one pill daily at the same time, starting on the first Sunday after your period begins.,Use backup contraception (e.g., condoms) for the first 7 days of the first cycle.,If you miss a pill, follow the specific instructions in the package insert based on how many you missed and the week of the cycle.,Common side effects include nausea, breast tenderness, and spotting; these often improve after 2-3 cycles.,Smoking increases the risk of serious cardiovascular side effects, especially if you are over 35 years old.,This medication does not protect against HIV or other sexually transmitted infections.
Take one tablet daily at the same time each day; do not skip doses.,Use an additional non-hormonal contraceptive (e.g., condoms) if you miss a pill, have vomiting, or diarrhea.,Smoking while on this pill increases the risk of blood clots and stroke, especially if you are over 35.,Contact your healthcare provider immediately if you have chest pain, leg pain/swelling, sudden vision changes, or severe headache.,This medication does not protect against HIV or other sexually transmitted infections.,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 ORTHO-NOVUM 7/14-28 vs ALYACEN 1/35, answered by our medical review team.
ORTHO-NOVUM 7/14-28 is a Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol and norethindrone. Suppresses gonadotropin release (FSH, LH) via negative feedback, inhibiting ovulation. Also increases cervical mucus viscosity and alters endometrial receptivity.. ALYACEN 1/35 is a Oral Contraceptive that works by Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on hypothalamic-pituitary axis; norethindrone induces progestational effects including cervical mucus thickening and endometrial changes, inhibiting ovulation and sperm penetration.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ORTHO-NOVUM 7/14-28 and ALYACEN 1/35 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 ORTHO-NOVUM 7/14-28 is: One tablet daily for 28 days; each tablet contains norethindrone 0.5 mg and ethinyl estradiol 0.035 mg (days 1-7), norethindrone 0.75 mg and ethinyl estradiol 0.035 mg (days 8-14), norethindrone 1 mg and ethinyl estradiol 0.035 mg (days 15-21), and placebo (days 22-28). Take at same time each day.. The standard adult dose of ALYACEN 1/35 is: One tablet (norethindrone 1 mg and ethinyl estradiol 35 mcg) orally once daily for 21 consecutive days, followed by 7 days of placebo or no tablets.. 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 ORTHO-NOVUM 7/14-28 and ALYACEN 1/35 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. ORTHO-NOVUM 7/14-28 is classified as Category C. First trimester: Post-marketing studies have not shown an increased risk of birth defects with combined oral contraceptives. However, inadvertent use during early pregnancy is not . ALYACEN 1/35 is classified as Category C. Pregnancy category X. Use of ALYACEN 1/35 (norethindrone/ethinyl estradiol) is contraindicated during pregnancy. First trimester: Increased risk of congenital anomalies, including . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.