Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CYCLAFEM 7/7/7 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. Ethinyl estradiol suppresses gonadotropin release (FSH, LH) via negative feedback on hypothalamic-pituitary axis; norethindrone induces endometrial changes that inhibit implantation and thickens cervical mucus.
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 (FDA-labeled),Treatment of moderate acne vulgaris in women ≥15 years (FDA-labeled for some triphasic formulations),Off-label: dysmenorrhea, endometriosis-associated pain, menstrual irregularity
Prevention of pregnancy
One tablet (norethindrone 0.5 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 0.75 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 1 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days. Dispensed in a 21-tablet pack with 7 placebo tablets. For contraception, take one tablet daily at same time each day for 28 days; begin next pack after 28-day cycle.
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.
Terminal half-life: 5-13 hours (mean 8 hrs); clinical context: supports every-28-day dosing interval for intramuscular depot.
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 hydroxylation and conjugation; ethinyl estradiol undergoes first-pass metabolism and enterohepatic recirculation. Norethindrone is metabolized to various reduced and conjugated metabolites.
Norethindrone: primarily hepatic via reduction and conjugation, with CYP3A4 involvement. Ethinyl estradiol: primarily via CYP3A4, also undergoes sulfation and glucuronidation.
Renal: ~50-60% as conjugated metabolites; Fecal: ~30-40% via bile; <1% unchanged.
Renal: ~50% (unchanged drug); Fecal: ~20% (via bile); Biliary: ~30% (metabolites). Total clearance is 12 L/h.
~97-99% bound, primarily to sex hormone-binding globulin (SHBG) and albumin.
98% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
2.5-4.5 L/kg; extensive tissue distribution including adipose tissue, brain, and reproductive organs.
0.35 L/kg (total body water distribution); in obesity, Vd increases to 0.5 L/kg due to lipophilicity.
Oral: ~100% (combination with ethinyl estradiol enhances absorption); IM: 100% (depot formulation).
Oral: 85% (with high-fat meal reduces to 70%); Sublingual: 90%.
No dose adjustment required for mild to moderate renal impairment. Not studied in severe renal impairment (GFR <30 m L/min); use is not recommended due to potential hormonal accumulation and increased thrombotic risk.
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 or chronic hepatic dysfunction (Child-Pugh class B or C) due to impaired metabolism of estrogen and progestin. For mild hepatic impairment (Child-Pugh class A), limited data; use alternative contraception if possible.
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.
Safety and efficacy not established in females younger than 18 years for contraception; however, postmenarchal adolescents may use standard adult dosing (after menarche). Weight-based dosing not applicable; use weight ≥45 kg with no dose adjustment. For other indications (e.g., acne), follow adult dosing in patients ≥15 years.
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 postmenopausal women (age >55 years) as no contraceptive benefit. If used off-label, no specific dose adjustment; however, consider increased risk of cardiovascular events (thrombosis, hypertension, stroke) and metabolic effects (glucose intolerance, lipid changes) in older women with additional risk factors. Use lowest effective dose if necessary.
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 (myocardial infarction, thromboembolism, stroke) from combination oral contraceptive use, especially in women >35 years and those who smoke ≥15 cigarettes/day.
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.
Thromboembolic disorders (DVT, PE, stroke, MI) – discontinue if symptoms occur,Hepatic disease (jaundice, hepatitis, cholestasis) – discontinue if develops,Hypertension – monitor blood pressure; discontinue if uncontrolled,Gallbladder disease – increased risk of cholelithiasis,Carbohydrate/lipid metabolism – monitor in diabetic or hyperlipidemic patients,Headache (including migraine) – discontinue if new or worsening,Uterine bleeding – rule out pregnancy if amenorrhea occurs,Depression – discontinue if severe,Ocular lesions (retinal thrombosis) – discontinue if 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
Smoking >15 cigarettes/day and age ≥35 years,History of DVT/PE or thromboembolic disorders,Cerebrovascular or coronary artery disease,Uncontrolled hypertension,Diabetes with vascular involvement,Migraine with focal aura (especially if >35 years),Breast cancer (current or history),Estrogen-dependent neoplasia,Liver tumors (benign or malignant) or active liver disease,Pregnancy or suspected pregnancy,Undiagnosed abnormal uterine bleeding,Use of ritonavir-boosted protease inhibitors (CYP3A4 induction reduces efficacy)
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 specific dietary restrictions are required. Grapefruit and grapefruit juice may modestly increase ethinyl estradiol levels, but this is not considered clinically relevant in most cases. Avoid excessive grapefruit intake to be cautious. The medication can be taken with or without food. High-fat meals may delay absorption of the hormones, but overall contraceptive efficacy is not affected.
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. First trimester: Major birth defects including neural tube defects, cardiovascular malformations, and oral clefts. Second/third trimester: Fetal demasculinization in males, potential for feminization. Post-natal: Long-term reproductive tract abnormalities.
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 ~0.2. Avoid breastfeeding due to potential estrogenic effects on infant. Alternative methods 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 dose adjustments applicable. Discontinue immediately if pregnancy occurs.
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.
Cyclafem 7/7/7 is a triphasic combined oral contraceptive containing ethinyl estradiol and norethindrone. The varying hormone doses across the three 7-day phases mimic the natural menstrual cycle. It is essential to start the first pack on the first day of menses for immediate contraceptive efficacy. Missed pills require specific instructions based on the week; if one pill is missed, take it as soon as remembered and continue. If two pills are missed in week 1 or 2, take two pills for two days, then resume. If two pills are missed in week 3, or three or more pills are missed at any time, use backup contraception for 7 days and consider starting a new pack. Breakthrough bleeding is common, especially in the first few cycles, and does not indicate contraceptive failure. Grapefruit juice may increase ethinyl estradiol levels, but clinical significance is minimal; still, avoid excessive intake.
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 each day, following the order of the pills in the pack (7 light yellow, 7 orange, 7 light green, then 7 white placebo).,If you miss a pill, refer to the package insert instructions based on how many pills you missed and the week you are in; use backup contraception if needed.,Common side effects include nausea, breast tenderness, and breakthrough bleeding, especially in the first 3 cycles; report severe symptoms.,Smoking increases the risk of serious cardiovascular side effects, especially in women over 35; do not smoke while on this medication.,Not all women can use combination oral contraceptives; inform your doctor if you have a history of blood clots, migraines with aura, liver disease, or certain cancers.,Use backup contraception (e.g., condoms) for the first 7 days if starting for the first time or after a break of more than 7 days.,Missed pills, vomiting, or diarrhea may reduce effectiveness; follow instructions for missed pills and use backup contraception.
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 CYCLAFEM 7/7/7 vs ALYACEN 7/7/7, answered by our medical review team.
CYCLAFEM 7/7/7 is a Oral Contraceptive that works by Combination estrogen-progestin contraceptive. Ethinyl estradiol suppresses gonadotropin release (FSH, LH) via negative feedback on hypothalamic-pituitary axis; norethindrone induces endometrial changes that inhibit implantation and thickens cervical mucus.. 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 CYCLAFEM 7/7/7 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 CYCLAFEM 7/7/7 is: One tablet (norethindrone 0.5 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 0.75 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 1 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days. Dispensed in a 21-tablet pack with 7 placebo tablets. For contraception, take one tablet daily at same time each day for 28 days; begin next pack after 28-day cycle.. 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 CYCLAFEM 7/7/7 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. CYCLAFEM 7/7/7 is classified as Category C. Pregnancy Category X. First trimester: Major birth defects including neural tube defects, cardiovascular malformations, and oral clefts. Second/third trimester: Fetal demasculiniza. 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.