Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
GENCEPT 10/11-28 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 ethinyl estradiol (estrogen) and levonorgestrel (progestin) inhibits ovulation by suppressing gonadotropin release, increases cervical mucus viscosity 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.
Female contraception
Prevention of pregnancy (FDA-approved)
One tablet (ethinyl estradiol 0.01 mg/levonorgestrel 0.1 mg) orally once daily for 28 days. For the first 21 days, active tablets are taken; the next 7 days are placebo tablets.
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
Terminal elimination half-life is approximately 8-12 hours. Steady state is achieved within 2-3 days.
Terminal elimination half-life: 12–15 hours. Steady-state achieved within 5 days with Q12H dosing.
Ethinyl estradiol: primarily CYP3A4; Levonorgestrel: CYP3A4, undergoes reduction and sulfation.
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.
Renal excretion accounts for approximately 70% of elimination (as unchanged drug and metabolites), with about 10% biliary/fecal. The remaining is metabolized.
Renal: 50% as unchanged drug and metabolites; fecal: 40% as metabolites; biliary: ~10% as glucuronide conjugates.
98% bound to serum proteins, primarily albumin and alpha-1-acid glycoprotein.
~99% bound to serum albumin and sex hormone-binding globulin.
Volume of distribution is approximately 0.8-1.0 L/kg, indicating extensive tissue distribution.
2.8 L/kg (apparent Vd), indicating extensive tissue distribution.
Oral bioavailability is approximately 90%, with minimal first-pass metabolism.
Oral: ~70% due to first-pass metabolism.
No dose adjustment required for mild to moderate renal impairment. In severe renal impairment (GFR <30 m L/min), use with caution due to potential fluid retention and hypertension.
No dose adjustment required for mild to moderate renal impairment. Not recommended for use in end-stage renal disease.
Contraindicated in patients with Child-Pugh class B or C hepatic impairment (moderate to severe). In mild hepatic impairment (Child-Pugh class A), use with caution due to altered hormone metabolism.
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 in pediatric patients before menarche. For post-menarche adolescents, follow same dosing as adults.
Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily) based on adult clinical trials.
Not indicated for use in women above 55 years of age due to increased risk of thromboembolic events and lack of efficacy data.
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 combination oral contraceptive use. Women over 35 who smoke should not use this product.
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 (thrombophlebitis, pulmonary embolism, stroke, MI),Visual abnormalities (retinal thrombosis, papilledema),Hepatic neoplasia (benign/malignant liver tumors),Hypertension,Glucose intolerance/diabetes,Gallbladder disease,Depression,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
Thrombophlebitis or thromboembolic disorders,Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma,Known or suspected pregnancy,Hypersensitivity to any component
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 specific food interactions are known. However, grapefruit juice may increase ethinyl estradiol levels; consider limiting grapefruit juice intake. Avoid excessive alcohol, as it may increase liver toxicity risk.
Grapefruit juice may increase ethinyl estradiol levels; avoid large quantities. No significant food restrictions. Administer with food if GI upset occurs.
GENCEPT 10/11-28 contains gestodene and ethinylestradiol. Gestodene is a progestogen; ethinylestradiol is an estrogen. Combined hormonal contraceptives are contraindicated in pregnancy. First trimester: no increased risk of major birth defects based on epidemiological studies, but should not be used once pregnancy is confirmed. Second and third trimesters: no therapeutic indication; animal studies show fetotoxicity at high doses. Overall, use is not recommended in pregnancy.
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.
Gestodene and ethinylestradiol are excreted in breast milk in small amounts. The M/P ratio for ethinylestradiol is approximately 0.02; for gestodene, it is unknown but likely low. Combined hormonal contraceptives may reduce milk production and composition, especially in early lactation; use is generally not recommended during breastfeeding, particularly in the first 6 months postpartum. Progestin-only alternatives are preferred.
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 adjustment is applicable as the drug is contraindicated in pregnancy. Pharmacokinetic changes in pregnancy (increased volume of distribution, altered hepatic metabolism) would theoretically reduce ethinylestradiol and gestodene levels, but since the drug is not used in pregnancy, no dosing recommendations are made.
Contraindicated in pregnancy; no dose adjustment recommended. If exposure occurs, immediate discontinuation is required. No pharmacokinetic data support safe use; avoid use entirely.
GENCEPT 10/11-28 is a combination oral contraceptive containing ethinyl estradiol 10 mcg and drospirenone 3 mg (24 active tablets) plus placebo (4 tablets). It is used for contraception and treatment of moderate acne vulgaris in women who desire oral contraception. The 24-day active regimen increases ovarian suppression and reduces breakthrough bleeding. Drospirenone has antimineralocorticoid activity, which may cause hyperkalemia in patients with renal impairment, hepatic disease, or adrenal insufficiency. Monitor potassium in at-risk patients. Do not use with other potassium-sparing drugs. Avoid in women with hypertension, diabetes with vascular disease, or migraine with aura due to increased cardiovascular risk with low-dose EE. Consider starting on first day of menses for immediate contraceptive effect.
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 pill daily at the same time, in the order shown on the pack. Do not skip pills.,Use backup contraception (e.g., condoms) if you miss a pill, vomit within 3-4 hours after taking a pill, or have severe diarrhea.,Contact your doctor immediately if you experience leg pain, chest pain, shortness of breath, severe headache, vision changes, or jaundice.,Cigarette smoking increases the risk of serious cardiovascular side effects. Do not smoke while taking this medication.,Store at room temperature, away from moisture and heat.
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 GENCEPT 10/11-28 vs AFIRMELLE, answered by our medical review team.
GENCEPT 10/11-28 is a Oral Contraceptive that works by Combination of ethinyl estradiol (estrogen) and levonorgestrel (progestin) inhibits ovulation by suppressing gonadotropin release, increases cervical mucus viscosity 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 GENCEPT 10/11-28 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 GENCEPT 10/11-28 is: One tablet (ethinyl estradiol 0.01 mg/levonorgestrel 0.1 mg) orally once daily for 28 days. For the first 21 days, active tablets are taken; the next 7 days are placebo tablets.. 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 GENCEPT 10/11-28 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. GENCEPT 10/11-28 is classified as Category C. GENCEPT 10/11-28 contains gestodene and ethinylestradiol. Gestodene is a progestogen; ethinylestradiol is an estrogen. Combined hormonal contraceptives are contraindicated in pregn. 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.