Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ENOVID 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 estrogen-progestin contraceptive; suppresses gonadotropins (LH, FSH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases viscosity of cervical mucus and alters endometrial lining to impair implantation.
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.
Oral contraception,Treatment of endometriosis,Dysfunctional uterine bleeding,Postponement of menstruation
Prevention of pregnancy
Oral, 5 mg daily for 20 days starting on day 5 of menstrual cycle for ovulation inhibition; for endometriosis, 5 mg daily for 15 days increasing to 10 mg daily if breakthrough bleeding occurs.
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.
Norethynodrel: 5-12 hours; mestranol: 7-20 hours. Terminal half-life of ethinyl estradiol from mestranol conversion: 10-30 hours. Clinical context: steady-state achieved after 3-5 half-lives (3-5 days).
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).
Hepatic via CYP3A4; norethynodrel is metabolized to norethindrone; mestranol is demethylated to ethinyl estradiol; metabolites undergo glucuronidation and sulfation.
Norethindrone: primarily hepatic via reduction and conjugation, with CYP3A4 involvement. Ethinyl estradiol: primarily via CYP3A4, also undergoes sulfation and glucuronidation.
Renal (30-50% as metabolites, <5% unchanged) and fecal (40-60% via bile, mostly as glucuronide conjugates).
Renal: ~50% (unchanged drug); Fecal: ~20% (via bile); Biliary: ~30% (metabolites). Total clearance is 12 L/h.
Norethynodrel: 95-97% bound to albumin; mestranol: >95% bound to albumin and sex hormone-binding globulin (SHBG).
98% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
Norethynodrel: ~2.0 L/kg; mestranol: ~3.5 L/kg. High Vd indicates extensive tissue distribution.
0.35 L/kg (total body water distribution); in obesity, Vd increases to 0.5 L/kg due to lipophilicity.
Oral: 80-100% for norethynodrel; mestranol: 40-60% (first-pass metabolism to ethinyl estradiol).
Oral: 85% (with high-fat meal reduces to 70%); Sublingual: 90%.
No specific dose adjustment guidelines; use with caution in severe renal impairment (GFR <30 m L/min) due to potential fluid retention.
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 severe hepatic impairment (Child-Pugh C); in mild to moderate impairment (Child-Pugh A or B), reduce dose by 50% or use alternative therapy.
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 recommended for use in pediatric patients for contraception; for endometriosis in adolescents, dose same as adult adjusted for weight (0.1-0.2 mg/kg/day norethynodrel equivalent, max 5 mg/day).
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 contraception in postmenopausal women; if used for other indications, monitor for thromboembolic events and electrolyte disturbances; initiate at lowest effective dose (2.5 mg/day).
Not indicated for use in postmenopausal women. No recommendations for geriatric population due to lack of indication.
Cigarette smoking increases risk of serious cardiovascular events; contraindicated in women over 35 who smoke.
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 (stroke, MI, DVT, PE), hepatic neoplasia, gallbladder disease, hypertension, glucose intolerance, and depression. Discontinue if jaundice or visual disturbances occur.
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, cerebrovascular or coronary artery disease, known or suspected breast carcinoma, undiagnosed abnormal genital bleeding, pregnancy, known or suspected estrogen-dependent neoplasia, impaired liver function, history of cholestatic jaundice of pregnancy, heavy smoking (>15 cigarettes/day) in women over 35.
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
No significant food interactions. Grapefruit juice may increase estrogen levels; avoid large amounts. Maintain consistent dietary habits to avoid fluctuations in hormone levels.
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.
First trimester: Risk of fetal cardiovascular defects, neural tube defects, and cleft lip/palate. Second and third trimesters: Possible feminization of male fetuses (hypospadias) and clitoral enlargement in females. Postnatal: Vaginal adenosis and clear cell adenocarcinoma of the vagina/cervix in females exposed in utero.
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.
Excretion into breast milk occurs; M/P ratio not established. Avoid use during breastfeeding due to potential hormonal effects on infant. Alternative contraception recommended.
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.
Contraindicated in pregnancy. No dosing adjustments applicable; if inadvertent exposure occurs, immediately discontinue the drug and provide counseling regarding risks.
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.
Monitor for thromboembolic events, especially in women over 35 who smoke. Use lowest effective dose for shortest duration. Discontinue 4 weeks before elective surgery to reduce clotting risk. Not recommended for contraception due to high estrogen dose.
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 at same time daily with food to reduce nausea.,Report symptoms of blood clots: chest pain, sudden shortness of breath, leg pain/swelling, severe headache, vision changes.,Do not use if pregnant or breastfeeding; seek alternative contraception.,Smoking increases risk of serious cardiovascular side effects.,Use backup contraception if vomiting occurs within 4 hours of dose.
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 ENOVID vs ALYACEN 7/7/7, answered by our medical review team.
ENOVID is a Oral Contraceptive that works by Combination estrogen-progestin contraceptive; suppresses gonadotropins (LH, FSH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases viscosity of cervical mucus and alters endometrial lining to impair implantation.. 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 ENOVID 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 ENOVID is: Oral, 5 mg daily for 20 days starting on day 5 of menstrual cycle for ovulation inhibition; for endometriosis, 5 mg daily for 15 days increasing to 10 mg daily if breakthrough bleeding occurs.. 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 ENOVID 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. ENOVID is classified as Category C. First trimester: Risk of fetal cardiovascular defects, neural tube defects, and cleft lip/palate. Second and third trimesters: Possible feminization of male fetuses (hypospadias) a. 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.