Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OVRAL-28 vs ALTAVERA
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: suppresses gonadotropin release via estrogen and progestin, inhibiting ovulation, thickening cervical mucus, and altering endometrial lining.
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,Treatment of moderate acne vulgaris in females aged ≥15 years who have no known contraindications and have achieved menarche
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet (norgestrel 0.3 mg, ethinyl estradiol 0.03 mg) orally once daily for 21 consecutive days, followed by 7 days of placebo.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Ethinyl estradiol: terminal half-life 13-27 hours (mean ~17 hours); norgestrel: terminal half-life 11-45 hours (mean ~24 hours). Clinical context: steady-state reached within 5-7 days; accumulation minimal with daily dosing.
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.
Ethinyl estradiol: primarily hepatic via CYP3A4, undergoes first-pass metabolism; norgestrel: hepatic reduction and conjugation, partially via 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: ~40% as metabolites; fecal: ~60% via biliary excretion, primarily as glucuronide and sulfate conjugates.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Ethinyl estradiol: 97-98% bound, primarily to albumin; norgestrel: 93-95% bound, primarily to sex hormone-binding globulin (SHBG) and albumin.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Ethinyl estradiol: 2.5-4.0 L/kg; norgestrel: 2.0-3.5 L/kg. High Vd indicates extensive tissue distribution and binding.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: ethinyl estradiol ~40-50% (due to first-pass metabolism); norgestrel ~60-70% (variable due to presystemic metabolism).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dosage adjustment required for mild to moderate renal impairment. Insufficient data for severe renal impairment (Cr Cl <30 m L/min); use with caution due to potential fluid retention.
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 acute hepatitis, hepatic adenomas, or severe cirrhosis (Child-Pugh class C). For mild to moderate impairment (Child-Pugh A or B), consider alternative therapy; if used, monitor liver function closely and reduce dose if tolerated.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (one tablet daily).
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 after menopause. No specific dosing adjustments provided for elderly patients; consider increased risk of thromboembolic events and cardiovascular disease.
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 risk of serious cardiovascular events. Combination oral contraceptives are contraindicated in women over 35 who 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.
Increased risk of thrombotic disorders (venous thromboembolism, stroke, MI),Elevated blood pressure,Gallbladder disease,Hepatic neoplasia,Glucose intolerance,Retinal thrombosis,Depression
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.
Current or history of thrombotic disorders,Known or suspected breast carcinoma,Undiagnosed abnormal genital bleeding,Hepatic adenoma or carcinoma,Known or suspected pregnancy,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 known; however, grapefruit juice may increase ethinyl estradiol exposure. High-fat meals may slightly reduce absorption but not clinically significant. Advise consistent intake with food to minimize gastrointestinal upset.
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.
Pregnancy category X. First trimester: risk of congenital malformations (neural tube defects, cardiovascular anomalies) and spontaneous abortion. Second and third trimesters: associated with fetal adrenal suppression, hepatic impairment, and potential for masculinization of female genitalia.
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.
Contraindicated during breastfeeding. Estrogens and progestins are excreted in human milk in low concentrations (M/P ratio not established). Potential for adverse effects on the infant including jaundice and breast enlargement.
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.
Contraindicated in pregnancy; no dose adjustments applicable. Discontinue immediately upon pregnancy confirmation.
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.
Ovral-28 is a combination oral contraceptive containing norgestrel and ethinyl estradiol. It is dosed as 28-day regimen with 21 active pills and 7 placebo. Patients should be counseled about the risk of thromboembolism, especially if over 35 years old and smoking. Efficacy may be reduced with concurrent use of certain anticonvulsants (e.g., phenytoin, carbamazepine) and antibiotics (e.g., rifampin). Instruct patients to take at the same time daily to maintain consistent serum levels. Missed doses require backup contraception; refer to package insert for missed pill algorithm.
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, preferably with a meal to reduce nausea.,Do not skip pills; if a pill is missed, follow the instructions in the patient information leaflet and use backup contraception as directed.,Smoking increases the risk of serious cardiovascular side effects, especially in women over 35. Avoid smoking while on this medication.,Use backup contraception (like condoms) when starting the pill and if you miss pills or take certain other medications.,Common side effects include nausea, headache, breast tenderness, and breakthrough bleeding, which often improve after 2-3 months.,Seek medical attention immediately if you experience symptoms of blood clots: sudden chest pain, shortness of breath, leg pain/swelling, or sudden severe headache.,This medication does not protect against HIV or other sexually transmitted infections.
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 OVRAL-28 vs ALTAVERA, answered by our medical review team.
OVRAL-28 is a Oral Contraceptive that works by Combination oral contraceptive: suppresses gonadotropin release via estrogen and progestin, inhibiting ovulation, thickening cervical mucus, and altering endometrial lining.. 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 OVRAL-28 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 OVRAL-28 is: One tablet (norgestrel 0.3 mg, ethinyl estradiol 0.03 mg) orally once daily for 21 consecutive days, followed by 7 days of placebo.. 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 OVRAL-28 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. OVRAL-28 is classified as Category C. Pregnancy category X. First trimester: risk of congenital malformations (neural tube defects, cardiovascular anomalies) and spontaneous abortion. Second and third trimesters: assoc. 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.