Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NORQUEST FE 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
NORQUEST FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone. Ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation. Norethindrone induces progestational changes in the endometrium, increasing cervical mucus viscosity, and also inhibits ovulation.
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
Prevention of pregnancy
One tablet orally once daily, each tablet containing 1 mg norethindrone acetate and 20 mcg ethinyl estradiol (21 active tablets) followed by 7 ferrous fumarate 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.
Terminal half-life: 6-8 hours. Clinical context: Supports once-daily dosing with sustained therapeutic effect.
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 metabolized via CYP3A4, with phase II conjugation (glucuronidation and sulfation). Norethindrone is metabolized via reduction and conjugation, primarily as sulfate and glucuronide conjugates.
Ethinyl estradiol: primarily hepatic via CYP3A4; norethindrone: hepatic reduction and sulfate conjugation.
Renal: 80% (50% unchanged, 30% as metabolites); Fecal: 19%; Biliary: <1%
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%).
97% bound to albumin and α1-acid glycoprotein.
Norethindrone: 61% bound to albumin and SHBG; ethinyl estradiol: 97-98% bound to albumin.
Vd: 3.5 L/kg (~245 L for 70 kg adult). Indicates extensive tissue distribution.
Norethindrone: 3.8-4.5 L/kg; ethinyl estradiol: 2.0-4.0 L/kg. Large Vd indicates extensive tissue distribution.
Oral: 92% (range 88-96%)
Oral: Norethindrone ~64%, ethinyl estradiol ~38-48% (due to first-pass metabolism).
No dose adjustment required for mild to moderate renal impairment. Not recommended for use in severe renal impairment (GFR <30 m L/min) due to lack of data.
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 hepatic impairment (Child-Pugh Class B or C). No specific dose adjustment for mild impairment; use with caution.
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.
Safety and efficacy not established in postmenarchal patients; dosing follows adult regimen if indicated.
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 dose adjustment recommended due to lack of data.
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 the risk of serious cardiovascular events from combination oral contraceptive use. Women over 35 years old 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, cardiovascular disease (especially in smokers over 35), hepatic neoplasia, gallbladder disease, hypertension, and glucose intolerance. Use with caution in women with risk factors for these conditions.
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
History of thrombophlebitis or thromboembolic disorders, cerebrovascular or coronary artery disease, known or suspected pregnancy, carcinoma of the breast, estrogen-dependent neoplasia, undiagnosed abnormal genital bleeding, jaundice with prior OCs, liver adenoma or carcinoma, hepatic impairment, and hypersensitivity to any component.
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
Avoid calcium-rich foods (milk, yogurt, cheese) within 2 hours of dose. Vitamin C (citrus fruits, tomatoes) enhances iron absorption. Coffee, tea, and red wine reduce iron absorption; avoid within 1 hour of dosing.
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.
Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: estrogen exposure associated with congenital anomalies including cardiovascular and neural tube defects. Second/third trimesters: linked to vaginal adenosis and cervical dysplasia in female offspring, potential for genitourinary abnormalities. Use of iron and calcium components generally safe, but hormonal components (estrogen/norethindrone) pose teratogenic risk.
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).
Not recommended during breastfeeding. Estrogen and progestin may reduce milk production and quality. Small amounts of steroids and iron are excreted in breast milk; M/P ratio not established for combined hormonal contraceptives. No specific data for NORQUEST FE; avoid use.
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.
Contraindicated in pregnancy; no dose adjustments recommended as drug should be discontinued. Pharmacokinetic changes in pregnancy (increased volume of distribution, altered hepatic metabolism) would necessitate dose increase if used, but use is contraindicated.
Contraindicated in pregnancy; no dose adjustments applicable. Discontinue medication immediately upon pregnancy detection.
Contains norethindrone acetate and ethinyl estradiol. Use for iron deficiency anemia due to menstrual blood loss; iron absorption enhanced with vitamin C. Monitor for thromboembolic events, especially in smokers over 35. May reduce menstrual flow and improve iron stores over 3-6 months.
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 with food to reduce nausea.,Iron may cause dark stools; this is harmless.,Avoid taking with dairy, calcium supplements, or antacids within 2 hours.,Report signs of blood clots: leg pain, chest pain, shortness of breath.,Continue for full course even if bleeding improves to prevent recurrence.
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 NORQUEST FE vs ALYACEN 1/35, answered by our medical review team.
NORQUEST FE is a Oral Contraceptive that works by NORQUEST FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone. Ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation. Norethindrone induces progestational changes in the endometrium, increasing cervical mucus viscosity, and also inhibits ovulation.. 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 NORQUEST FE 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 NORQUEST FE is: One tablet orally once daily, each tablet containing 1 mg norethindrone acetate and 20 mcg ethinyl estradiol (21 active tablets) followed by 7 ferrous fumarate 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 NORQUEST FE 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. NORQUEST FE is classified as Category C. Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: estrogen exposure associated with congenital anomalies including cardiovascular and n. 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.