Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CYCLESSA vs AFIRMELLE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination of estrogen (ethinyl estradiol) and progestin (desogestrel) inhibits ovulation by suppressing gonadotropin release, increases viscosity of cervical mucus to impede sperm penetration, and alters endometrial receptivity.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial receptivity.
Prevention of pregnancy
Prevention of pregnancy (FDA-approved)
One tablet (0.15 mg desogestrel/0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
Desogestrel: 38±13 hours (terminal); ethinyl estradiol: 14±3 hours (terminal). Steady-state reached after 7-10 days.
Terminal elimination half-life: 12–15 hours. Steady-state achieved within 5 days with Q12H dosing.
Ethinyl estradiol is metabolized primarily via CYP3A4; desogestrel is converted to active metabolite etonogestrel via CYP2C9 and CYP2C19.
Ethinyl estradiol undergoes first-pass metabolism in gut and liver via CYP3A4, with conjugation to sulfate and glucuronide. Levonorgestrel is metabolized primarily by CYP3A4 to reduced and hydroxylated metabolites, then conjugated.
Urine (50-60% as metabolites, <10% unchanged); feces (30-40% as metabolites); enterohepatic circulation.
Renal: 50% as unchanged drug and metabolites; fecal: 40% as metabolites; biliary: ~10% as glucuronide conjugates.
Desogestrel: 99.7% (SHBG); ethinyl estradiol: 98.5% (albumin, SHBG).
~99% bound to serum albumin and sex hormone-binding globulin.
Desogestrel: 1.0-1.5 L/kg (extensive tissue distribution); ethinyl estradiol: 0.15-0.35 L/kg (limited).
2.8 L/kg (apparent Vd), indicating extensive tissue distribution.
Desogestrel: 76% (oral); ethinyl estradiol: 55% (oral, variable due to first-pass metabolism).
Oral: ~70% due to first-pass metabolism.
No dose adjustment required for mild to moderate renal impairment. Insufficient data for severe impairment (Cr Cl <30 m L/min); use with caution.
No dose adjustment required for mild to moderate renal impairment. Not recommended for use in end-stage renal disease.
Contraindicated in Child-Pugh class C (severe hepatic impairment). For mild to moderate (Child-Pugh A or B), use with caution: reduce estrogen dose or discontinue if intolerance occurs.
Contraindicated in acute hepatic disease or severe (Child-Pugh C) hepatic impairment. Use with caution in mild to moderate hepatic impairment; monitor liver function.
Not indicated for use before menarche. For postmenarchal adolescents, dose same as adults: 0.15 mg desogestrel/0.02 mg ethinyl estradiol daily.
Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily) based on adult clinical trials.
Not indicated for postmenopausal women. No studies in geriatric population; use not recommended due to lack of benefit and increased thromboembolic risk with age.
Not indicated for use in postmenopausal women; no specific dose adjustment required in healthy elderly, but limited data available.
Cigarette smoking increases risk of serious cardiovascular events from combined hormonal contraceptives. Risk increases with age and amount smoked (especially in women >35 years who smoke). Women should not use CYCLESSA if they smoke cigarettes and are over 35 years old.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (especially in women over 35) and with heavy smoking (15+ cigarettes/day). Women who use combination hormonal contraceptives should be strongly advised not to smoke.
Thrombotic disorders (venous thromboembolism, arterial thromboembolism),Cerebrovascular disease,Cardiovascular disease including myocardial infarction,Liver disease including hepatic adenoma,Increased blood pressure,Gallbladder disease,Carbohydrate and lipid metabolism effects,Headache,Bleeding irregularities
Thrombotic disorders (venous thromboembolism, stroke, myocardial infarction),Cigarette smoking (increases cardiovascular risk),Hypertension (especially in women with renal disease or migraines),Gallbladder disease,Hepatic neoplasia (benign and malignant),Carbohydrate and lipid metabolism effects,Ocular lesions (retinal thrombosis),Depressed mood or depression,Uterine bleeding irregularities,Reduced efficacy with hepatic enzyme inducers
Known or suspected pregnancy,Current or past breast cancer or other estrogen-sensitive cancer,Current or past deep vein thrombosis or pulmonary embolism,Current or history of thrombogenic valvular or rhythm disease,Cerebrovascular or coronary artery disease,Uncontrolled hypertension,Major surgery with prolonged immobilization,Diabetes with vascular involvement,Severe liver disease or liver tumor,Undiagnosed abnormal uterine bleeding,Age >35 years and smoking
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast cancer, endometrial cancer, or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior oral contraceptive use,Hepatic adenoma or carcinoma (current or history),Known or suspected pregnancy,Hypersensitivity to any component of the product,Heavy smoking (≥15 cigarettes/day) in women over 35
No significant food interactions. Grapefruit juice may slightly increase estrogen levels but not clinically relevant. Alcohol does not affect efficacy but may increase risk of liver damage with high doses.
Grapefruit juice may increase ethinyl estradiol levels; avoid large quantities. No significant food restrictions. Administer with food if GI upset occurs.
First trimester: The use of combined hormonal contraceptives containing desogestrel and ethinyl estradiol is not associated with an increased risk of major birth defects. Discontinuation due to first-trimester exposure is not indicated. Second and third trimesters: Prolonged exposure to estrogen-progestin combinations has been associated with rare risks such as congenital heart defects and limb reduction defects in case-control studies, but absolute risk is low. Fetal risk from inadvertent use in pregnancy is minimal; termination not recommended.
Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: exposure associated with congenital anomalies (e.g., cardiovascular, neural tube defects). Second and third trimesters: increased risk of fetal growth restriction, preterm birth, and neonatal respiratory distress. Postnatal: possible long-term developmental effects.
Small amounts of contraceptive steroids and/or metabolites have been identified in breast milk. Studies with combined oral contraceptives suggest possible effects on milk production and composition; use during lactation should be postponed until the infant is weaned or at least 6 months postpartum. M/P ratio for ethinyl estradiol and desogestrel metabolites is not well established; limited data suggest low transfer.
Contraindicated during breastfeeding. Small amounts of ethinyl estradiol and norethindrone are excreted in breast milk; M/P ratio not well defined. Potential for adverse effects on infant (e.g., jaundice, breast enlargement). May reduce milk production and quality.
No dose adjustments are applicable as CYCLESSA is contraindicated during pregnancy. In the event of inadvertent use, the drug should be discontinued as soon as pregnancy is confirmed. No pharmacokinetic-based dose changes are required because use is not recommended in pregnancy.
Contraindicated in pregnancy; no dose adjustment recommended. If exposure occurs, immediate discontinuation is required. No pharmacokinetic data support safe use; avoid use entirely.
CYCLESSA (desogestrel/ethinyl estradiol) is a monophasic oral contraceptive. It may be used off-label for acne treatment. Breakthrough bleeding is common in the first 3 cycles. CYP3A4 inducers (e.g., rifampin) reduce efficacy; consider backup contraception.
Afirmelle (levonorgestrel/ethinyl estradiol) is a combined oral contraceptive. Counsel patients to take at the same time daily to maintain consistent hormone levels. Use back-up contraception if a dose is missed. Monitor for signs of thromboembolism, especially in smokers over 35. Advise that certain antibiotics (e.g., rifampin) and anticonvulsants (e.g., phenytoin) may reduce efficacy. Consider progestin-only pill if contraindications to estrogen exist.
Take one tablet daily at the same time, even if no intercourse.,Start on the first day of menstrual period or first Sunday after period starts.,Use backup contraception for first 7 days if starting after day 5.,Missed pill: take as soon as remembered. If more than 2 missed, use backup method.,Vomiting or diarrhea may reduce effectiveness.,Report unexplained leg pain, chest pain, severe headache, or vision changes.,Smoking increases risk of serious cardiovascular side effects, especially if over 35.
Take one pill at the same time every day, even if you don't have sex.,If you miss a pill, follow the instructions in the package insert or ask your healthcare provider.,Use a backup method (like condoms) if you start late or miss pills.,This medication does not protect against HIV or other sexually transmitted infections.,Common side effects include nausea, breast tenderness, and breakthrough bleeding.,Seek medical help if you have symptoms of a blood clot: sudden chest pain, leg swelling, or shortness of breath.,Smoking while on this pill increases your risk of serious cardiovascular events.
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 CYCLESSA vs AFIRMELLE, answered by our medical review team.
CYCLESSA is a Oral Contraceptive that works by Combination of estrogen (ethinyl estradiol) and progestin (desogestrel) inhibits ovulation by suppressing gonadotropin release, increases viscosity of cervical mucus to impede sperm penetration, and alters endometrial receptivity.. AFIRMELLE is a Combined Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial receptivity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CYCLESSA and AFIRMELLE 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 CYCLESSA is: One tablet (0.15 mg desogestrel/0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.. The standard adult dose of AFIRMELLE is: One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.. 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 CYCLESSA and AFIRMELLE 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. CYCLESSA is classified as Category C. First trimester: The use of combined hormonal contraceptives containing desogestrel and ethinyl estradiol is not associated with an increased risk of major birth defects. Discontin. AFIRMELLE is classified as Category C. Pregnancy category X. Contraindicated in pregnancy due to risk of fetal harm. First trimester: exposure associated with congenital anomalies (e.g., cardiovascular, neural tube defe. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.