Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ENPRESSE-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
ENPRESSE-28 is a combined hormonal contraceptive containing ethinyl estradiol and desogestrel. It acts by suppressing gonadotropin release (FSH and LH) from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering the endometrium.
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 in women who elect to use oral contraceptives
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
1 tablet (ethinyl estradiol 0.035 mg / norgestimate 0.25 mg) orally once daily for 21 days, followed by 7 placebo days.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Terminal elimination half-life is 18-24 hours, allowing once-daily dosing; steady-state achieved within 5-7 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 primarily metabolized by CYP3A4; desogestrel is a prodrug converted to its active metabolite etonogestrel, which is further metabolized by CYP3A4, CYP2C9, and CYP2C19. Both undergo extensive first-pass metabolism.
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.
Primarily renal excretion as unchanged drug (70-80%) and glucuronide conjugate (15-20%); biliary/fecal elimination accounts for <5%.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
98% bound primarily to albumin and alpha-1 acid glycoprotein.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
0.2 L/kg; indicates distribution primarily in extracellular fluid with minimal tissue binding.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: 40-50%; reduced by high-fat meal (10-20% decrease).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dosage adjustment required for mild to moderate renal impairment. Not studied in severe renal impairment; contraindicated in patients with renal disease.
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 hepatic disease or history of cholestatic jaundice with prior oral contraceptive use. No adjustment provided for mild impairment; avoid use in Child-Pugh B or C.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Safety and efficacy not established in females before menarche. Post-menarche: use same dosing as adults (1 tablet daily for 21 days, then 7 placebo days).
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 geriatric dosing considerations.
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. This risk increases with age and with the number of cigarettes smoked, and is quite marked in women over 35 years of age. Women over 35 who smoke should not use combination oral contraceptives.
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.
Thromboembolic disorders: Venous and arterial thrombotic events, including pulmonary embolism, stroke, and myocardial infarction, especially in smokers and women with risk factors.,Hepatic disease: Discontinue if jaundice or hepatotoxicity develops.,Hypertension: Monitor blood pressure; discontinue if hypertension occurs.,Carcinoma of the breast and reproductive organs: Use with caution in women with a history of breast cancer or hormone-sensitive tumors.,Gallbladder disease: Increased risk of gallbladder disease.,Carbohydrate and lipid metabolism: May impair glucose tolerance and affect lipid levels.,Headache: Evaluate new or worsening migraine patterns.,Hereditary angioedema: Can trigger or exacerbate symptoms.,Depression: Monitor for development or worsening of 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.
Hypersensitivity to any component,Current or history of deep vein thrombosis or pulmonary embolism,Cerebrovascular or coronary artery disease (current or history),Thrombogenic valvular or rhythm disorders (e.g., atrial fibrillation),Uncontrolled hypertension (BP >160/100 mm Hg),Major surgery with prolonged immobilization,Diabetes mellitus with vascular involvement,Headaches with focal neurological symptoms or migraine with aura (age ≥35),Current or history of breast cancer or other estrogen-sensitive neoplasia,Active liver disease or history of liver tumors (benign or malignant),Undiagnosed abnormal uterine bleeding,Pregnancy (known or suspected),Cocarcinogenicity with hepatitis C drugs containing ombitasvir/paritaprevir/ritonavir (increased ALT elevations)
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
Grapefruit and grapefruit juice should be avoided as they inhibit CYP3A4 and can increase ethinylestradiol levels, potentially increasing the risk of estrogen-related adverse effects (e.g., thromboembolism, hypertension). No other specific food interactions are clinically significant.
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. First trimester: High risk of fetal malformations including craniofacial defects, cardiac anomalies, and neural tube defects. Second and third trimesters: Continued risk of teratogenicity; contraindicated in pregnancy.
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. Small amounts excreted into breast milk; M/P ratio approximately 0.62. Potential for serious adverse effects in nursing infants, including cardiovascular and renal effects.
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 as drug is contraindicated during pregnancy. No dose adjustment recommendations due to lack of safe use.
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.
ENPRESSE-28 is a combined oral contraceptive containing ethinylestradiol 0.035 mg and norgestimate 0.18/0.215/0.25 mg in a triphasic regimen. For missed pills, follow the CDC/USMEC guidelines: if one active pill is missed, take it as soon as remembered and continue schedule; if two or more are missed, take the most recent missed pill, discard others, use backup contraception for 7 days, and consider emergency contraception if unprotected intercourse occurred. Monitor for thromboembolic events, especially in smokers over 35, and counsel on increased risk. Concomitant use of certain anticonvulsants (e.g., phenytoin, carbamazepine), rifampin, or St. John's Wort may reduce contraceptive efficacy; consider alternative contraception. Assess for contraindications including migraine with aura, hypertension (>160/100), or history of DVT/PE.
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 each day, starting on the first day of your menstrual period or the Sunday after your period begins as directed.,If you miss a pill, refer to the package insert for instructions; use backup contraception (condoms) if needed and consider emergency contraception if unprotected sex occurred.,Common side effects include nausea, breast tenderness, headache, and breakthrough bleeding; these often improve within a few months.,This medication does not protect against sexually transmitted infections (STIs); use condoms for STI prevention.,Seek medical attention immediately for symptoms of blood clots such as sudden leg pain/swelling, chest pain, shortness of breath, severe headache, or vision changes.,Avoid grapefruit and grapefruit juice while taking this medication as it may increase estrogen levels and side effects.,Inform your healthcare provider of all medications and supplements you take, including St. John's Wort, antibiotics, and anticonvulsants, as they may reduce effectiveness.,Smoking while using this pill increases the risk of serious cardiovascular side effects; do not smoke, especially if you are over 35 years old.
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 ENPRESSE-28 vs ALTAVERA, answered by our medical review team.
ENPRESSE-28 is a Oral Contraceptive that works by ENPRESSE-28 is a combined hormonal contraceptive containing ethinyl estradiol and desogestrel. It acts by suppressing gonadotropin release (FSH and LH) from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering the endometrium.. 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 ENPRESSE-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 ENPRESSE-28 is: 1 tablet (ethinyl estradiol 0.035 mg / norgestimate 0.25 mg) orally once daily for 21 days, followed by 7 placebo days.. 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 ENPRESSE-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. ENPRESSE-28 is classified as Category C. FDA Pregnancy Category X. First trimester: High risk of fetal malformations including craniofacial defects, cardiac anomalies, and neural tube defects. Second and third trimesters:. 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.