Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DAYSEE vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
DAYSEE (estradiol/norethindrone acetate) is a combination hormonal contraceptive that suppresses gonadotropins (FSH and LH) via negative feedback of estrogen and progestin, thereby inhibiting ovulation. Norethindrone also increases cervical mucus viscosity and induces endometrial atrophy.
Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
FDA-approved: Prevention of pregnancy in women who elect to use an oral contraceptive.,Off-label: Treatment of dysmenorrhea, menstrual cycle regulation, and emergency contraception (off-label use of extended-cycle regimen).
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One active tablet (norgestimate 0.18 mg/ethinyl estradiol 0.025 mg) orally once daily for 21 days, followed by 7 days of placebo. Each cycle: 7 days placebo, then 21 days active.
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 approximately 24 hours (range 18-36 hours), supporting once-daily dosing for steady state within 5 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.
Estradiol is metabolized primarily via hydroxylation (CYP1A2, CYP3A4) and conjugation to glucuronides and sulfates. Norethindrone is metabolized via reduction and conjugation (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 70% (metabolites), biliary/fecal 30% (parent drug and metabolites). No active drug excreted unchanged.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
99% bound to albumin (secondary to alpha-1-acid glycoprotein).
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
10-15 L/kg (large distribution into tissues, including pancreas and liver).
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: 75% (high; food reduces rate but not extent).
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No specific dose adjustment provided. Use with caution in patients with renal impairment; monitor 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 patients with impaired liver function or active liver disease. No specific dose adjustment recommended.
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.
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 postmenopausal women; no relevant use 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 contraceptives. This risk increases with age (>35 years) and with the number of cigarettes smoked. Women who use combination hormonal 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.
Thrombotic disorders: venous thromboembolism, arterial thromboembolism (e.g., stroke, MI), especially in smokers ≥35 years.,Hepatic disease: discontinue if jaundice occurs; may cause cholestatic jaundice.,Hypertension: monitor blood pressure; discontinue if significant hypertension develops.,Gallbladder disease: increased risk of gallstones.,Carbohydrate/lipid metabolism: monitor in women with diabetes or hypertriglyceridemia.,Headache: evaluate if new or worsening migraine; discontinue if neurological signs.,Uterine bleeding: irregular bleeding may occur; rule out pregnancy.,Depression: monitor; discontinue if severe.,Hereditary angioedema: may exacerbate.,Ocular effects: discontinue if vision loss or proptosis.
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 thrombophlebitis or venous thromboembolic disorders.,Cerebrovascular or coronary artery disease.,Known or suspected breast carcinoma.,Carcinoma of the endometrium or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding.,Cholestatic jaundice of pregnancy or jaundice with prior oral contraceptive use.,Hepatic adenoma or carcinoma, or active liver disease.,Tobacco use in women ≥35 years.
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. Grapefruit juice may increase ethinyl estradiol levels; avoid large amounts. Consistent consumption of St. John's wort, certain antiepileptics (e.g., phenytoin), and rifampin can reduce contraceptive efficacy.
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.
Daysee (progestin-only pill) has a low teratogenic risk. First trimester: no increased risk of major malformations. Second and third trimesters: no known adverse fetal effects. No association with congenital anomalies.
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.
Compatible with breastfeeding. Progestin-only pills do not suppress lactation. Levonorgestrel is excreted in breast milk in small amounts; estimated infant dose <1% of maternal weight-adjusted dose. M/P ratio not available.
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.
No dose adjustment is indicated; Daysee is contraindicated during pregnancy. Pregnancy should be ruled out before initiation. No pharmacokinetic changes require dose alteration.
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.
Daysee (ethinyl estradiol/levonorgestrel) is a combined oral contraceptive (COC) with a 91-day extended cycle regimen (84 active pills, 7 placebo). It reduces the frequency of withdrawal bleeds to 4 per year. Efficacy may be reduced if active pills are missed within the first 7 days of a new cycle. Use backup contraception if vomiting or diarrhea occurs within 3-4 hours of taking a pill.
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; missing pills increases pregnancy risk.,You will have fewer periods (about 4 per year) while on Daysee.,Use a backup method (e.g., condoms) if you miss a pill or have severe GI upset.,Do not smoke while on this medication; smoking increases risk of serious cardiovascular side effects.,Inform your doctor if you experience severe headaches, chest pain, or leg swelling.
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 DAYSEE vs ALTAVERA, answered by our medical review team.
DAYSEE is a Oral Contraceptive that works by DAYSEE (estradiol/norethindrone acetate) is a combination hormonal contraceptive that suppresses gonadotropins (FSH and LH) via negative feedback of estrogen and progestin, thereby inhibiting ovulation. Norethindrone also increases cervical mucus viscosity and induces endometrial atrophy.. 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 DAYSEE 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 DAYSEE is: One active tablet (norgestimate 0.18 mg/ethinyl estradiol 0.025 mg) orally once daily for 21 days, followed by 7 days of placebo. Each cycle: 7 days placebo, then 21 days active.. 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 DAYSEE 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. DAYSEE is classified as Category C. Daysee (progestin-only pill) has a low teratogenic risk. First trimester: no increased risk of major malformations. Second and third trimesters: no known adverse fetal effects. No . 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.