Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
BLISOVI FE 1/20 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 of ethinyl estradiol, an estrogen, and desogestrel, a progestin, which inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation and altering cervical mucus and endometrial lining to reduce likelihood of fertilization 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,Treatment of heavy menstrual bleeding,Treatment of acne (off-label),Treatment of dysmenorrhea (off-label)
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet orally once daily for 21 days, followed by 7 days of placebo (iron-containing) tablets. Each active tablet contains 0.1 mg levonorgestrel and 20 mcg ethinyl estradiol.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Ethinyl estradiol: ~12-14 hours; norethindrone: ~7-8 hours; both allow once-daily dosing with steady-state reached within 7-10 days.
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 is metabolized primarily by CYP3A4; desogestrel is a prodrug converted to etonogestrel, which is metabolized by CYP2C9 and 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; fecal: ~40-50% via biliary elimination; less than 10% unchanged in urine.
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 albumin); norethindrone: ~93-95% bound (primarily albumin and SHBG).
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; norethindrone: ~3.5-4.5 L/kg; large Vd indicates extensive tissue distribution.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); norethindrone ~50-70% (first-pass metabolism reduced with micronized formulation).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dose adjustment required for mild to moderate renal impairment. Not studied in severe renal impairment (e GFR <30 m L/min/1.73 m²) or end-stage renal disease; use contraindicated due to potential for fluid retention and hypertension.
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 Child-Pugh Class B or C (moderate to severe hepatic impairment) due to reduced steroid clearance. Use with caution in Child-Pugh Class A; monitor liver function.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Use post-menarche. Standard dose: one tablet orally once daily for 21 days, then 7 days of placebo. 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. No specific dose adjustment; efficacy and safety not established in geriatric population.
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. Risk increases with age and number of cigarettes smoked, particularly in women over 35 years old.
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 venous thromboembolism and arterial thrombosis,Increased risk of myocardial infarction and stroke, especially in smokers,Liver disease including hepatic adenoma and hepatocellular carcinoma,Hypertension,Gallbladder disease,Carbohydrate and lipid metabolism effects,Headache including migraine,Uterine bleeding irregularities,Depression,Hereditary angioedema,Chloasma,Ocular lesions (e.g., retinal thrombosis)
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.
Known or suspected pregnancy,Current or history of thromboembolic disorders (e.g., deep vein thrombosis, pulmonary embolism),Cerebrovascular or coronary artery disease,Known or suspected breast cancer or other estrogen-sensitive neoplasia,Undiagnosed abnormal uterine bleeding,Liver tumors or active liver disease,Migraine with aura if age ≥35,Diabetes with vascular involvement,Uncontrolled hypertension,Major surgery with prolonged immobilization,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 specific food restrictions. May be taken with or without food. Grapefruit juice may increase ethinyl estradiol levels but not clinically significant. Avoid St. John's wort (reduces efficacy). Alcohol consumption is not contraindicated but may increase side effects like nausea or dizziness.
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.
Tri 1: No increased risk of birth defects in large cohort studies; however, combined hormonal contraceptives are contraindicated in pregnancy due to potential fetal harm from estrogen. Tri 2 & 3: No known teratogenicity; continuation after confirmed pregnancy not indicated.
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.
Small amounts of ethinyl estradiol and norethindrone excreted in breast milk; no adverse effects reported. M/P ratio: Not available. Avoid use during breastfeeding if possible due to potential reduction in milk production.
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; discontinue if pregnancy occurs. No dose adjustment applicable in pregnancy.
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.
BLISOVI FE 1/20 is a combination oral contraceptive containing norethindrone acetate (1 mg) and ethinyl estradiol (20 mcg) with ferrous fumarate (75 mg) as an iron supplement in the placebo pills. The low estrogen dose may increase breakthrough bleeding risk, especially in the first few cycles. The ferrous fumarate tablets are not intended for contraceptive effect; ensure patients take active pills correctly. Missed pill management: if one active pill is missed, take as soon as remembered; if two or more active pills are missed, use backup contraception for 7 days and consider emergency contraception. Active pill color is pink; placebo pills are brown (ferrous fumarate). Contraindications: history of thromboembolic events, migraine with aura, liver disease, undiagnosed abnormal uterine bleeding, breast cancer, or pregnancy. Monitor for hypertension, depression, and cholestasis. Drug interactions: CYP3A4 inducers (e.g., rifampin, phenytoin, carbamazepine, St. John's wort) reduce efficacy; antibiotics may also reduce efficacy (except rifampin-like drugs, which are definite).
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 in the evening to reduce nausea.,The pill pack contains 21 active pink pills (hormonal) and 7 brown placebo pills (contain iron).,You will have a withdrawal bleed during the placebo week, typically starting 2-3 days after the last active pill.,If you miss a dose, refer to the package instructions: for one missed active pill, take it as soon as remembered; if more than one missed, use a backup method for 7 days.,Inform your healthcare provider if you experience severe abdominal pain, chest pain, shortness of breath, headache, visual changes, or leg pain/swelling.,Smoking increases the risk of serious cardiovascular side effects; avoid smoking, especially if over 35 years old.,This medication does not protect against sexually transmitted infections; use condoms for prevention.,The iron in placebo pills may cause dark stools; this is harmless.,Store at room temperature away from moisture and heat.
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 BLISOVI FE 1/20 vs ALTAVERA, answered by our medical review team.
BLISOVI FE 1/20 is a Oral Contraceptive that works by Combination of ethinyl estradiol, an estrogen, and desogestrel, a progestin, which inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation and altering cervical mucus and endometrial lining to reduce likelihood of fertilization 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 BLISOVI FE 1/20 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 BLISOVI FE 1/20 is: One tablet orally once daily for 21 days, followed by 7 days of placebo (iron-containing) tablets. Each active tablet contains 0.1 mg levonorgestrel and 20 mcg ethinyl estradiol.. 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 BLISOVI FE 1/20 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. BLISOVI FE 1/20 is classified as Category C. Tri 1: No increased risk of birth defects in large cohort studies; however, combined hormonal contraceptives are contraindicated in pregnancy due to potential fetal harm from estro. 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.