Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DEMULEN 1/35-21 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 oral contraceptive containing ethinyl estradiol (estrogen) and ethynodiol diacetate (progestin). Inhibits gonadotropin secretion (FSH, LH) via negative feedback on hypothalamic-pituitary axis, suppressing ovulation. Additionally, thickens cervical mucus and alters endometrial receptivity.
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,Treatment of moderate acne vulgaris in women at least 15 years old who have achieved menarche and are seeking contraception,Oral contraceptive for women over 35 who smoke (off-label: not recommended due to increased cardiovascular risk)
Prevention of pregnancy
One tablet orally once daily for 21 days, followed by 7 days off. Each tablet contains 1 mg ethynodiol diacetate and 35 mcg ethinyl estradiol.
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.
Ethinyl estradiol: 13±3 hours (terminal); norethindrone: 8±3 hours. Steady-state achieved after ~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).
Ethinyl estradiol: primarily metabolized by CYP3A4 hydroxylation and conjugation; undergoes enterohepatic recirculation. Ethynodiol diacetate: rapidly deacetylated to norethindrone, which is metabolized by CYP3A4 and CYP2C9; undergoes reduction, hydroxylation, and conjugation.
Norethindrone: primarily hepatic via reduction and conjugation, with CYP3A4 involvement. Ethinyl estradiol: primarily via CYP3A4, also undergoes sulfation and glucuronidation.
Renal (primarily as glucuronide and sulfate conjugates): ~60%; fecal: ~40%
Renal: ~50% (unchanged drug); Fecal: ~20% (via bile); Biliary: ~30% (metabolites). Total clearance is 12 L/h.
Ethinyl estradiol: 97–98% bound to albumin; norethindrone: 93–97% bound to albumin and SHBG
98% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
Ethinyl estradiol: 2.5–4 L/kg; norethindrone: 3.5–5 L/kg. Indicates extensive tissue distribution.
0.35 L/kg (total body water distribution); in obesity, Vd increases to 0.5 L/kg due to lipophilicity.
Ethinyl estradiol: ~45% (first-pass metabolism); norethindrone: ~65% (first-pass metabolism). Oral administration only.
Oral: 85% (with high-fat meal reduces to 70%); Sublingual: 90%.
No dose adjustment required for renal impairment. However, caution in severe renal impairment 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 Child-Pugh class B and C (moderate to severe hepatic impairment). Use with caution in mild impairment (Child-Pugh A) with monitoring.
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 indicated for use before menarche. Post-menarche: use same dosing as adults; monitor for bone health and growth.
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 use in postmenopausal women due to lack of efficacy and increased thromboembolic risk.
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 from combination oral contraceptive use. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
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 (e.g., stroke, DVT, PE),Increased risk of myocardial infarction, especially in smokers and women with hypertension or hyperlipidemia,Hepatic neoplasia (benign/malignant),Gallbladder disease,Hypertension,Carbohydrate and lipid metabolism changes,Ocular lesions (e.g., retinal thrombosis),Depression,Fluid retention,Irregular bleeding,Possible reduced efficacy with enzyme-inducing drugs (e.g., rifampin, anticonvulsants),Chloasma,Pregnancy (should be ruled out before use)
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 (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast carcinoma,Known or suspected estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Known or suspected pregnancy,Benign or malignant liver tumor (current or history),Severe hepatic impairment or acute liver disease,Hypersensitivity to any component,Age over 35 and smoking (≥15 cigarettes/day),Uncontrolled hypertension (systolic ≥160 mm Hg or diastolic ≥100 mm Hg),Diabetes with vascular involvement,Migraine with focal aura (if age ≥35),Major surgery with prolonged immobilization
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 slightly increase estrogen levels but not clinically relevant. Avoid St. John's Wort as it reduces contraceptive efficacy. No dietary restrictions.
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: increased risk of cardiovascular defects (RR ~1.3) and oral clefts (RR ~1.1) with exposure; second and third trimesters: no proven association with major malformations, but may cause masculinization of female genitalia if high doses of progestins (ethynodiol diacetate is a weak progestin, risk low). Postnatal: potential for neonatal jaundice (due to estrogen).
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 in small amounts (estrogen and progestin levels ~1% of maternal dose; M/P ratio not well defined). May reduce milk quality and quantity; use only if benefits outweigh risks, preferably after weaning.
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.
No dose adjustments; contraindicated during pregnancy due to fetal risks. If used inadvertently, discontinue immediately.
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.
Demulen 1/35-21 (ethinyl estradiol 35 mcg, ethynodiol diacetate 1 mg) is a monophasic combined oral contraceptive. It has lower estrogen dose than many older pills but still carries thromboembolic risk. Advise patients to take at same time daily. Missed pill protocols: if missed >12 hours, take pill ASAP and continue; if missed 2 or more pills, use backup contraception for 7 days. Consider non-contraceptive benefits: improved cycle regularity, reduced dysmenorrhea, decreased acne. Monitor blood pressure and liver function. Contraindications: history of DVT/PE, active liver disease, breast cancer, pregnancy, migraine with aura. Smoking increases thromboembolic risk significantly, especially in women >35.
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 for 21 days, then no pills for 7 days; you will have withdrawal bleeding during the free week.,If you miss a pill by less than 12 hours, take it immediately and continue on schedule. If more than 12 hours, take the missed pill and use backup contraception (condoms) for the next 7 days.,Common side effects include nausea, headache, breast tenderness, breakthrough bleeding, and mood changes; these often improve after the first few months.,Seek medical help for symptoms of blood clots: sudden leg pain/swelling, chest pain, shortness of breath, sudden severe headache or vision changes.,Do not smoke while taking this medication; smoking increases risk of serious cardiovascular side effects, especially if over 35.,This pill does not protect against sexually transmitted infections; use condoms for STI prevention.
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 DEMULEN 1/35-21 vs ALYACEN 7/7/7, answered by our medical review team.
DEMULEN 1/35-21 is a Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol (estrogen) and ethynodiol diacetate (progestin). Inhibits gonadotropin secretion (FSH, LH) via negative feedback on hypothalamic-pituitary axis, suppressing ovulation. Additionally, thickens cervical mucus and alters endometrial receptivity.. 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 DEMULEN 1/35-21 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 DEMULEN 1/35-21 is: One tablet orally once daily for 21 days, followed by 7 days off. Each tablet contains 1 mg ethynodiol diacetate and 35 mcg ethinyl estradiol.. 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 DEMULEN 1/35-21 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. DEMULEN 1/35-21 is classified as Category C. First trimester: increased risk of cardiovascular defects (RR ~1.3) and oral clefts (RR ~1.1) with exposure; second and third trimesters: no proven association with major malformat. 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.