Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OVULEN vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Ovulen is a combination oral contraceptive containing ethynodiol diacetate (a progestin) and mestranol (an estrogen). It inhibits ovulation by suppressing gonadotropin-releasing hormone (Gn RH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion from the pituitary. It also increases cervical mucus viscosity and alters endometrial development, impeding sperm penetration and implantation.
Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
Prevention of pregnancy (FDA-approved indication)
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
1 tablet (1 mg ethynodiol diacetate, 50 mcg mestranol) orally once daily for 21 days, followed by 7 days of placebo or no medication.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Ethinylestradiol: 10-20 hours (mean 17 hours); Dimethisterone: 10-15 hours. Clinical context: Steady state achieved after 3-5 days; elimination prolonged in hepatic impairment.
Levonorgestrel: terminal elimination half-life 25±10 hours; ethinyl estradiol: 13±7 hours. Clinical context: steady-state concentrations achieved within 5-7 days; contraceptive efficacy requires consistent daily dosing.
Ethynodiol diacetate is rapidly metabolized to norethindrone, primarily via hydrolysis, then undergoes reduction, hydroxylation, and conjugation. Mestranol is metabolized to ethinyl estradiol via demethylation, followed by further hydroxylation and conjugation. Both are metabolized by cytochrome P450 enzymes, including CYP3A4.
Ethinyl estradiol: primarily metabolized by CYP3A4; undergoes sulfation and glucuronidation. Desogestrel: rapidly converted to active metabolite etonogestrel via CYP2C9 and CYP2C19; further metabolism by CYP3A4.
Renal: 50-60% as metabolites (glucuronide and sulfate conjugates), biliary/fecal: 40-50% (enterohepatic circulation).
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Ethinylestradiol: 97-98% bound to albumin and sex hormone-binding globulin (SHBG); Dimethisterone: ~90% bound to albumin and SHBG.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Ethinylestradiol: 2-4 L/kg (large Vd indicating extensive tissue distribution, including reproductive tissues and fat); Dimethisterone: 1.5-2.5 L/kg.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: Ethinylestradiol 40-60% (first-pass metabolism); Dimethisterone ~70% (oral bioavailability).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No specific dose adjustment guidelines available; use caution in severe renal impairment (Cr Cl <30 m L/min) due to potential hormonal accumulation.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal disease or acute renal failure due to potential fluid retention.
Contraindicated in severe hepatic impairment (Child-Pugh class C). In mild to moderate impairment (Child-Pugh A or B), use with caution; no specific dose reduction established.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Approved only for postmenarchal adolescents; same dosing as adults (1 tablet daily for 21 days with 7-day break). Not indicated before menarche.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
Not indicated for use in postmenopausal women. Efficacy and safety in elderly (age >65 years) have not been established.
Not indicated for postmenopausal women. No specific geriatric dosing; consider increased risk of thromboembolism, cardiovascular disease, and metabolic effects in older women of reproductive age.
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. The risk increases with age, especially in women over 35 years, and with the number of cigarettes smoked. Women who use combination oral contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events from combined oral contraceptives. Risk increases with age (especially >35 years) and with number of cigarettes smoked. Women who use combined hormonal contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of cardiovascular events; avoid in women over 35 who smoke.,Increased risk of thromboembolic disorders (e.g., deep vein thrombosis, pulmonary embolism, stroke, myocardial infarction). Discontinue if thrombotic events occur or are suspected.,Elevated blood pressure; monitor regularly.,Gallbladder disease; may worsen or precipitate.,Hepatic neoplasia; rare cases of benign and malignant liver tumors reported.,Carcinoma of breast and reproductive organs; increased risk with long-term use; monitor if history.,Ocular lesions; discontinue if sudden partial or complete loss of vision, proptosis, diplopia, or papilledema occurs.,Glucose intolerance; use with caution in diabetics.,Unscheduled bleeding; rule out pregnancy or other causes.,Depression; discontinue if severe or recurrent.
Thrombotic disorders: risk of venous thromboembolism (VTE), stroke, myocardial infarction; discontinue if thrombotic event occurs.,Hepatic disease: discontinue if jaundice or liver function abnormalities develop.,Hypertension: monitor blood pressure; discontinue if uncontrolled.,Carbohydrate metabolism: may affect glucose tolerance; monitor diabetic patients.,Depression: discontinue if significant depression occurs.,Gallbladder disease: increased risk of cholelithiasis.
Thrombophlebitis or thromboembolic disorders (current or history).,Cerebrovascular or coronary artery disease (current or history).,Known or suspected breast carcinoma.,Estrogen-dependent neoplasia (known or suspected).,Undiagnosed abnormal genital bleeding.,Pregnancy (known or suspected).,Benign or malignant liver tumor (current or history).,Jaundice or liver disease (acute or chronic) with abnormal liver function, unless improving.,Hypersensitivity to any component.
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast carcinoma,Estrogen-dependent neoplasia (known or suspected),Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma (known or suspected),Pregnancy (known or suspected),Hypersensitivity to any component
No significant food interactions. Grapefruit juice may alter estrogen metabolism but clinical relevance is minimal. Maintain regular diet; no restrictions.
No significant food interactions. Alcohol does not affect efficacy but may increase risk of adverse effects such as nausea. Grapefruit juice has no known interaction. Avoid excessive alcohol consumption due to potential hepatotoxicity.
FDA Pregnancy Category X. Contraindicated in pregnancy due to risk of fetal harm, including cardiovascular anomalies and limb defects. First trimester exposure associated with major congenital malformations; second and third trimester exposure may cause feminization of male fetuses.
ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular defects (relative risk 1.2-1.4) and no consistent increase in other major malformations. Second and third trimesters: No known teratogenic effects, but theoretical risks from estrogenic effects (e.g., feminization of male fetus). Postnatal: No increased risk of long-term developmental effects from pregnancy exposure.
Excreted in human milk; M/P ratio not established. May reduce milk production and affect infant hormonal development. Contraindicated during breastfeeding.
Combined oral contraceptives may reduce milk production and quality, especially in early lactation. Ethinyl estradiol transfers into breast milk at low levels (M/P ratio approximately 0.1-0.2), excluding clinical effects in term infants. Levonorgestrel transfer is minimal (M/P ratio ~0.2-0.4). Use is generally avoided in breastfeeding women, especially during the first 6 weeks postpartum. Progestin-only methods are preferred.
Not applicable; contraindicated in pregnancy. No dose adjustments recommended as medication should be discontinued immediately if pregnancy occurs.
Contraindicated in pregnancy. No dose adjustment recommended because use is discontinued upon confirmed or suspected pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased hepatic clearance, altered binding proteins) are not relevant for this indication.
Ovulen (ethynodiol diacetate 1 mg + mestranol 0.1 mg) is a first-generation combined oral contraceptive. Monitor for thromboembolic events, especially in smokers over 35. Use with caution in patients with hypertension, migraine with aura, or liver disease. Breakthrough bleeding is common in the first 3 cycles.
ALTAVERA is a combined oral contraceptive (COC) containing ethinylestradiol and levonorgestrel. It inhibits ovulation via suppression of gonadotropins. Counsel patients to take at the same time daily to maintain efficacy. Missed pill management: if missed within 12 hours, take immediately; if >12 hours, take last missed pill and use backup contraception for 7 days. Be aware of increased VTE risk, especially in smokers over 35. May reduce effectiveness of lamotrigine; monitor seizure control. Initiate on the first day of menses or first Sunday after onset.
Take one pill daily at the same time, even if no sexual activity.,Use backup contraception (e.g., condoms) for the first 7 days of starting the pill.,Report sudden severe headache, chest pain, leg swelling, or vision changes immediately.,Smoking increases risk of serious cardiovascular side effects; avoid smoking.,Missed pills increase pregnancy risk; follow missed pill instructions in the patient leaflet.
Take one tablet daily at the same time each day, with or without food.,If you miss a pill by less than 12 hours, take it as soon as you remember. If more than 12 hours, take the missed pill and use a backup method (e.g., condoms) for the next 7 days.,Smoking increases your risk of serious cardiovascular side effects, especially if you are over 35 years old. Do not smoke while taking this medication.,Seek immediate medical attention if you experience sudden severe headache, chest pain, leg pain/swelling, or vision changes (symptoms of blood clots).,This medication does not protect against HIV or other sexually transmitted infections.,If you are taking lamotrigine or other anticonvulsants, tell your doctor; your seizure medication may be less effective.,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 OVULEN vs ALTAVERA, answered by our medical review team.
OVULEN is a Oral Contraceptive that works by Ovulen is a combination oral contraceptive containing ethynodiol diacetate (a progestin) and mestranol (an estrogen). It inhibits ovulation by suppressing gonadotropin-releasing hormone (Gn RH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion from the pituitary. It also increases cervical mucus viscosity and alters endometrial development, impeding sperm penetration and implantation.. ALTAVERA is a Combined Oral Contraceptive that works by Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OVULEN and ALTAVERA depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of OVULEN is: 1 tablet (1 mg ethynodiol diacetate, 50 mcg mestranol) orally once daily for 21 days, followed by 7 days of placebo or no medication.. The standard adult dose of ALTAVERA is: 1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.. 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 OVULEN and ALTAVERA 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. OVULEN is classified as Category C. FDA Pregnancy Category X. Contraindicated in pregnancy due to risk of fetal harm, including cardiovascular anomalies and limb defects. First trimester exposure associated with majo. ALTAVERA is classified as Category C. ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular def. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.