Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CRYSELLE vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Cryselle is a combination oral contraceptive containing ethinyl estradiol and norgestrel. It inhibits ovulation by suppressing gonadotropin release, primarily through estrogenic and progestogenic effects on the hypothalamic-pituitary axis. It also increases cervical mucus viscosity and alters endometrial structure, 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,Off-label: Acne vulgaris, dysmenorrhea, menorrhagia, endometriosis-associated pain, menstrual cycle regulation, emergency contraception (sometimes off-label)
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet (0.3 mg norgestrel/0.03 mg ethinyl estradiol) orally once daily at the same time each day 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.
Terminal elimination half-life approximately 24 hours (range 16-36 h), with clinical significance for once-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 undergoes first-pass metabolism in the gut wall and liver, primarily via CYP3A4, and is also involved in conjugation (glucuronidation and sulfation). Norgestrel is metabolized in the liver via reduction and conjugation, with the active isomer levonorgestrel undergoing hydroxylation by 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% as metabolites, 20% unchanged), fecal (30%), with enterohepatic recirculation.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
95-98% bound to serum albumin and sex hormone-binding globulin.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Approximately 2 L/kg (40-60 L total), indicating extensive tissue distribution.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Oral: 85-90% due to first-pass metabolism; otherwise 100% for IV.
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dose adjustment required for mild to moderate renal impairment. Contraindicated in patients with acute or chronic renal failure due to potential for fluid retention and electrolyte disturbances.
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 Child-Pugh Class B or C cirrhosis or active liver disease. Use with caution in Child-Pugh Class A; consider alternative therapy if hepatotoxicity risk outweighs benefits.
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 premenarchal girls. Postmenarchal adolescents: same dosing as adults (0.3 mg norgestrel/0.03 mg ethinyl estradiol once daily for 21 days, then 7 days placebo).
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 dosing adjustments recommended for elderly patients, but use with caution due to 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 the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age and with heavy smoking (≥15 cigarettes per day) and is marked in women over 35 years of age. 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.
Cardiovascular events (thrombophlebitis, venous thrombosis, arterial thromboembolism, myocardial infarction, stroke, pulmonary embolism),Hepatic neoplasia (benign and malignant),Gallbladder disease,Carbohydrate and lipid metabolism effects,Elevated blood pressure,Ocular lesions (retinal thrombosis),Headache (including migraine with focal symptoms),Irregular bleeding,Depression,Lactation (may decrease milk production),Hereditary angioedema exacerbation,Chloasma
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,Endometrial carcinoma or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma (current or history),Known or suspected pregnancy,Hypersensitivity to any component,Heavy smoking (≥15 cigarettes/day) and age >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 interactions; however, grapefruit juice may increase estrogen levels slightly but clinical significance is minimal. St. John's Wort reduces contraceptive efficacy. High-fat meals can increase absorption of estrogen.
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.
CRYSELLE (levonorgestrel/ethinyl estradiol) is contraindicated in pregnancy. First trimester: no increased risk of major birth defects from inadvertent use, but postmarketing data limited. Second and third trimesters: associated with increased risk of fetal harm including cardiovascular and genital anomalies, and potential feminization of male fetuses due to progestin exposure.
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 breast milk; M/P ratio approximately 0.1-0.5 for levonorgestrel and 0.02-0.1 for ethinyl estradiol. Combined hormonal contraceptives may reduce milk production and quality; use alternative contraception during breastfeeding. Not recommended while nursing.
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 dosing adjustments applicable as use is contraindicated during pregnancy. Pharmacokinetic changes of pregnancy (increased volume of distribution, altered metabolism) would require dose increase if used, but due to fetal risk, do not administer.
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.
Crysell is a combination oral contraceptive containing ethinyl estradiol and norgestrel. It is also used off-label for dysmenorrhea and endometriosis-associated pain. Monitor for hypertension, thromboembolic events, and hepatic adenoma. Smoking increases thromboembolism risk, especially in women over 35. Breakthrough bleeding common in first 3 cycles; if persistent, rule out pregnancy or missed pills. Altered efficacy with hepatic enzyme inducers (e.g., rifampin, carbamazepine).
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 tablet daily at the same time; do not skip doses.,Missed pills increase pregnancy risk; follow instructions in package insert.,Antibiotics (except rifampin) do not decrease effectiveness, but rifampin requires backup contraception.,Smoking while on this pill increases risk of blood clots, especially if over 35.,Report severe headaches, vision changes, chest pain, leg swelling or pain, or shortness of breath.,This does not protect against HIV or other STIs.,Breakthrough bleeding is common in first few months; contact provider if heavy or persistent.,If vomiting or diarrhea within 4 hours of a pill, take another pill and use backup contraception.
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 CRYSELLE vs ALTAVERA, answered by our medical review team.
CRYSELLE is a Oral Contraceptive that works by Cryselle is a combination oral contraceptive containing ethinyl estradiol and norgestrel. It inhibits ovulation by suppressing gonadotropin release, primarily through estrogenic and progestogenic effects on the hypothalamic-pituitary axis. It also increases cervical mucus viscosity and alters endometrial structure, 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 CRYSELLE 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 CRYSELLE is: One tablet (0.3 mg norgestrel/0.03 mg ethinyl estradiol) orally once daily at the same time each day 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 CRYSELLE 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. CRYSELLE is classified as Category C. CRYSELLE (levonorgestrel/ethinyl estradiol) is contraindicated in pregnancy. First trimester: no increased risk of major birth defects from inadvertent use, but postmarketing data . 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.