Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
HAILEY FE 1/20 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 (FSH and LH) release via negative feedback on the hypothalamic-pituitary-ovarian axis, inhibiting ovulation. Also alters cervical mucus and endometrial lining to impair sperm penetration and implantation.
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.
FDA-approved for prevention of pregnancy.
Prevention of pregnancy
One tablet orally once daily for 21 consecutive days followed by 7 days of placebo tablets.
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: approximately 17 ± 5 hours (terminal); Norethindrone: approximately 8 ± 2 hours (terminal). Clinical context: Steady-state reached within 7-10 days; once-daily dosing maintains effective concentrations for contraceptive efficacy.
Norethindrone: 8-11 hours (terminal); ethinyl estradiol: 10-20 hours (terminal). The half-life supports once-daily dosing for oral contraceptive efficacy.
Ethinyl estradiol is primarily metabolized via CYP3A4 hydroxylation and conjugation (glucuronidation/sulfation). Norethindrone is metabolized by reduction, hydroxylation, and conjugation, primarily via CYP3A4.
Ethinyl estradiol: primarily hepatic via CYP3A4; norethindrone: hepatic reduction and sulfate conjugation.
Renal (approximately 50-60% as metabolites, including glucuronide conjugates of ethinyl estradiol and norethindrone, and about 20% as unchanged norethindrone); Fecal (approximately 30-40% as metabolites); Biliary (minor, with enterohepatic circulation of ethinyl estradiol conjugates).
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: approximately 97-98% bound to albumin (primarily) and sex hormone-binding globulin (SHBG); Norethindrone: approximately 93-95% bound to albumin and SHBG.
Norethindrone: 61% bound to albumin and SHBG; ethinyl estradiol: 97-98% bound to albumin.
Ethinyl estradiol: approximately 2-4 L/kg; Norethindrone: approximately 4-6 L/kg. Clinical meaning: Extensive tissue distribution, with accumulation in adipose tissue and 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 ~40-45% (first-pass metabolism); Norethindrone ~60-65% (first-pass metabolism).
Oral: Norethindrone ~64%, ethinyl estradiol ~38-48% (due to first-pass metabolism).
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure due to risk of hyperkalemia.
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 active liver disease or Child-Pugh class B or C cirrhosis. For Child-Pugh class A, use with caution and monitor liver function.
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-menarchal adolescents, same dosing as adults: one tablet orally once daily for 21 days, then 7 days of placebo.
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. No specific geriatric dosing adjustments; consider increased risk of thromboembolic events and cardiovascular disease.
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 (e.g., stroke, myocardial infarction, thromboembolism) from combination oral contraceptives. Risk increases with age (>35 years) and heavy smoking (≥15 cigarettes/day). Women who are >35 years old and 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 thrombotic disorders including venous thromboembolism, stroke, and myocardial infarction.,Discontinue if sudden partial or complete loss of vision or onset of proptosis, diplopia, migraine.,Elevated blood pressure; use caution in hypertension.,Gallbladder disease; increased risk of gallstones.,Carbohydrate and lipid metabolism effects; use caution in diabetes and hyperlipidemia.,Hepatic neoplasia; discontinue if jaundice or liver dysfunction.,Chloasma; avoid sun or UV exposure.,Bleeding irregularities; may cause breakthrough bleeding and spotting.,Possible decreased efficacy with concomitant enzyme-inducing drugs.
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
Thrombophlebitis or thromboembolic disorders (current or history).,Cerebrovascular or coronary artery disease (current or history).,Known or suspected breast carcinoma or estrogen-dependent neoplasia.,Undiagnosed abnormal genital bleeding.,Pregnancy (known or suspected).,Benign or malignant liver tumor (active or history).,Active liver disease with abnormal liver function.,Hypersensitivity to any component.,Age >35 years with cigarette smoking.
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
No specific food interactions. Grapefruit juice may increase estrogen levels; avoid excessive consumption. St. John's Wort may reduce efficacy. Consistent intake with or without food is recommended to maintain steady-state levels.
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: No increased risk of major birth defects in large epidemiological studies. Second and third trimesters: Use is not recommended due to potential adverse effects on fetal development, including possible estrogenic effects and association with congenital anomalies in animal studies. Fetal risk cannot be ruled out.
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).
Excreted in breast milk in small amounts. Estrogen and progestin levels may affect milk composition and reduce milk production. M/P ratio not reported; use caution, especially in the immediate postpartum period. Avoid use in breastfeeding women if possible.
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.
No dose adjustment established; use is contraindicated during pregnancy. If inadvertent exposure occurs, discontinue immediately. Pharmacokinetic changes in pregnancy (increased clearance, volume of distribution) do not warrant dose adjustment because the drug is contraindicated.
Contraindicated in pregnancy; no dose adjustments applicable. Discontinue medication immediately upon pregnancy detection.
Contains ethinyl estradiol 20 mcg and norethindrone 1 mg. Consider lower estrogen dose for patients with estrogen-sensitive migraines or history of thromboembolism. Monitor for breakthrough bleeding, especially in first 3 cycles. CYP3A4 inducers like rifampin may reduce efficacy. Check pregnancy test before initiating if delayed menses. Use with caution in patients with hypertriglyceridemia.
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 tablet daily at the same time, in the order listed on the pack.,If you miss a dose, take it as soon as remembered; if more than 24 hours late, use backup contraception.,Common side effects: nausea, breast tenderness, spotting, and headache.,Report signs of blood clots: sudden leg pain, chest pain, or shortness of breath.,Smoking increases risk of serious cardiovascular side effects, especially if over 35 years old.,Antibiotics (except rifampin) do not reduce effectiveness; inform your provider about all medications.
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 HAILEY FE 1/20 vs ALYACEN 1/35, answered by our medical review team.
HAILEY FE 1/20 is a Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol and norethindrone. Suppresses gonadotropin (FSH and LH) release via negative feedback on the hypothalamic-pituitary-ovarian axis, inhibiting ovulation. Also alters cervical mucus and endometrial lining to impair sperm penetration and implantation.. 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 HAILEY FE 1/20 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 HAILEY FE 1/20 is: One tablet orally once daily for 21 consecutive days followed by 7 days of placebo tablets.. 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 HAILEY FE 1/20 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. HAILEY FE 1/20 is classified as Category C. First trimester: No increased risk of major birth defects in large epidemiological studies. Second and third trimesters: Use is not recommended due to potential adverse effects on . 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.