Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CRYSELLE vs ALYACEN 7/7/7
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 norethindrone (progestin) and ethinyl estradiol (estrogen) that inhibits gonadotropin release from the pituitary, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.
Prevention of pregnancy,Off-label: Acne vulgaris, dysmenorrhea, menorrhagia, endometriosis-associated pain, menstrual cycle regulation, emergency contraception (sometimes off-label)
Prevention of pregnancy
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.
ALYACEN 7/7/7 is a combination oral contraceptive containing ethinyl estradiol 0.02 mg and drospirenone 3 mg. One tablet taken orally once daily for 28 days (7 active, 7 placebo, 7 active) without a hormone-free interval.
Terminal elimination half-life approximately 24 hours (range 16-36 h), with clinical significance for once-daily dosing.
Terminal elimination half-life is 14 hours (range 12-16 h) in healthy adults; prolonged to 24-30 h in moderate renal impairment (Cr Cl 30-50 m L/min).
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.
Norethindrone: primarily hepatic via reduction and conjugation, with CYP3A4 involvement. Ethinyl estradiol: primarily via CYP3A4, also undergoes sulfation and glucuronidation.
Renal (50% as metabolites, 20% unchanged), fecal (30%), with enterohepatic recirculation.
Renal: ~50% (unchanged drug); Fecal: ~20% (via bile); Biliary: ~30% (metabolites). Total clearance is 12 L/h.
95-98% bound to serum albumin and sex hormone-binding globulin.
98% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
Approximately 2 L/kg (40-60 L total), indicating extensive tissue distribution.
0.35 L/kg (total body water distribution); in obesity, Vd increases to 0.5 L/kg due to lipophilicity.
Oral: 85-90% due to first-pass metabolism; otherwise 100% for IV.
Oral: 85% (with high-fat meal reduces to 70%); Sublingual: 90%.
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.
Contraindicated in patients with severe renal impairment (Cr Cl <30 m L/min) or acute renal failure due to drospirenone's antimineralocorticoid activity. No dose adjustment recommended for mild to moderate impairment (Cr Cl ≥30 m L/min).
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 patients with acute hepatic disease, hepatic tumors, or impaired liver function (Child-Pugh class B or C). Discontinue if jaundice or pruritus develops. No dose adjustment for Child-Pugh class A.
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 in pediatric patients before menarche. Safety and efficacy in postmenarchal adolescents are expected to be similar to adults; dose is same as adults.
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 use in postmenopausal women. No recommendations for geriatric population due to lack of indication.
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 (COCs). Risk increases with age and amount smoked (especially >15 cigarettes/day). Women over 35 who smoke should not use COCs.
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 (thrombophlebitis, pulmonary embolism, cerebral hemorrhage, myocardial infarction),Cerebrovascular disease,Carcinoma of the breast or reproductive organs,Hepatic adenoma or carcinoma,Ocular lesions (retinal thrombosis, papilledema),Gallbladder disease,Carbohydrate/lipid effects,Elevated blood pressure,Hereditary angioedema,Chloasma,Hepatic impairment
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
Breast cancer (current or history),Undiagnosed abnormal genital bleeding,Known or suspected pregnancy,Current or history of thrombotic disorders (DVT, PE, stroke, MI),Cerebrovascular or coronary artery disease,Valvular heart disease with complications,Severe hypertension,Diabetes with vascular disease,Headaches with focal neurological symptoms (e.g., migraine with aura),Major surgery with prolonged immobilization,Known thrombophilia (e.g., Factor V Leiden, prothrombin mutation, protein S/C deficiency),Active liver disease (tumors, hepatitis, cirrhosis),Uncontrolled hypertension,Smoking (if age >35),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.
Grapefruit and grapefruit juice may increase ethinyl estradiol levels, potentially increasing side effects. St. John's wort (herbal supplement) can reduce contraceptive efficacy. No other significant food interactions; however, maintaining a stable intake of vitamin C and folate is generally recommended.
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.
ALYACEN 7/7/7 contains ethinylestradiol and norethindrone. First trimester: No increased risk of major birth defects based on epidemiologic studies; however, inadvertent use does not warrant termination. Second and third trimesters: Avoid use due to potential adverse effects on fetal development, including feminization of male fetuses and potential for congenital anomalies from progestin. Postnatal: Possible long-term effects on reproductive development.
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.
Contraindicated in breastfeeding. Ethinylestradiol reduces milk quantity and quality. Norethindrone is excreted in low amounts (M/P ratio approximately 0.3-0.4). However, combination oral contraceptives are not recommended during lactation due to estrogen effects on milk production.
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.
ALYACEN 7/7/7 is contraindicated in pregnancy; no dose adjustments are applicable as use is not recommended. Pharmacokinetic changes in pregnancy (increased clearance of steroids) would theoretically require higher doses, but due to fetal risks, alternative therapies should be used.
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).
ALYACEN 7/7/7 is a triphasic oral contraceptive containing ethinyl estradiol and norgestimate. The 7/7/7 regimen refers to the varying doses of norgestimate across three 7-day phases (0.18 mg, 0.215 mg, 0.25 mg) with a fixed 0.025 mg ethinyl estradiol. Use consistent 7-day placebo interval. Consider increased risk of venous thromboembolism (VTE) in patients with BMI >30, smoking >15 cigarettes/day, or age >35. Monitor for breakthrough bleeding, especially during the first 3 cycles. Avoid in patients with migraine with aura, uncontrolled hypertension, or history of DVT/PE. Drug interactions with CYP3A4 inducers (e.g., rifampin, carbamazepine) may reduce efficacy; consider backup contraception.
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 pill daily at the same time each day, in the order specified on the pack (active pills followed by placebo).,If you miss a pill, follow the package instructions; missing pills increases pregnancy risk, especially if placebo week is extended.,Common side effects include nausea, headache, breast tenderness, and spotting, which usually improve after 2-3 cycles.,Seek immediate medical attention for severe abdominal pain, chest pain, shortness of breath, leg pain/swelling, or severe headache.,This medication does not protect against HIV/AIDS or other sexually transmitted infections (STIs).,Inform your healthcare provider if you smoke, as smoking increases risk of serious cardiovascular side effects, especially if over 35 years.
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 ALYACEN 7/7/7, 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.. ALYACEN 7/7/7 is a Oral Contraceptive that works by Combination of norethindrone (progestin) and ethinyl estradiol (estrogen) that inhibits gonadotropin release from the pituitary, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CRYSELLE and ALYACEN 7/7/7 depend on the specific clinical indication. These are both Oral Contraceptive agents 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 ALYACEN 7/7/7 is: ALYACEN 7/7/7 is a combination oral contraceptive containing ethinyl estradiol 0.02 mg and drospirenone 3 mg. One tablet taken orally once daily for 28 days (7 active, 7 placebo, 7 active) without a hormone-free interval.. 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 ALYACEN 7/7/7 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 . ALYACEN 7/7/7 is classified as Category C. ALYACEN 7/7/7 contains ethinylestradiol and norethindrone. First trimester: No increased risk of major birth defects based on epidemiologic studies; however, inadvertent use does n. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.