Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
MODEYSO vs DESOGEN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
The mechanism of action of MODEYSO (elacestrant) is not fully elucidated. Elacestrant is an estrogen receptor antagonist that binds to estrogen receptor alpha (ERα) and degrades it, inhibiting estrogen-mediated signaling and tumor growth in ER-positive breast cancer.
Progestin (desogestrel) combined with ethinyl estradiol inhibits gonadotropin release, suppressing ovulation. Also increases cervical mucus viscosity, impeding sperm penetration.
Treatment of postmenopausal women or adult men with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.
Prevention of pregnancy,Treatment of moderate acne vulgaris in females at least 15 years old who have no known contraindications, have achieved menarche, and are unresponsive to topical therapy,Treatment of heavy menstrual bleeding (off-label)
400 mg orally once daily with food
One tablet (0.15 mg desogestrel and 0.03 mg ethinyl estradiol) orally once daily for 21 consecutive days, followed by 7 hormone-free days.
Terminal half-life approximately 6 days (range 4–10 days) in healthy subjects; supports weekly dosing interval
The terminal elimination half-life of etonogestrel is approximately 30-41 hours. This long half-life supports once-daily dosing for contraceptive efficacy.
Elacestrant is metabolized primarily by CYP3A4 and CYP2C8.
Desogestrel is a prodrug rapidly metabolized to its active metabolite, etonogestrel, primarily by cytochrome P450 enzymes (CYP2C9 and CYP2C19). Ethinyl estradiol is metabolized by CYP3A4 and undergoes glucuronidation.
Renal excretion unchanged: <1%; biliary/fecal elimination: >99% as unchanged drug
Desogestrel is primarily metabolized to its active metabolite etonogestrel, which is extensively metabolized and excreted as conjugates. About 50-60% is excreted via urine and 30-40% via feces. Less than 1% is excreted unchanged.
Negligible (<2%) binding to plasma proteins
Etonogestrel is 95-98% bound to plasma proteins, primarily albumin and sex hormone-binding globulin (SHBG). Desogestrel itself is about 80% bound to albumin.
Vd approximately 0.15 L/kg, consistent with distribution primarily in blood volume
The apparent volume of distribution of etonogestrel is approximately 1.3-1.6 L/kg. This relatively large Vd indicates extensive tissue distribution.
Intravenous only; bioavailability 100%
Oral bioavailability of desogestrel is essentially complete due to rapid and extensive metabolism to etonogestrel. The absolute bioavailability of etonogestrel after oral desogestrel is about 76-80%.
No dosage adjustment required for mild to moderate renal impairment (GFR ≥30 m L/min). Not recommended in severe renal impairment (GFR <30 m L/min) or end-stage renal disease.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment (Cr Cl <30 m L/min) due to potential estrogen accumulation.
Mild hepatic impairment (Child-Pugh A): No adjustment. Moderate hepatic impairment (Child-Pugh B): Reduce to 200 mg once daily. Severe hepatic impairment (Child-Pugh C): Avoid use.
Contraindicated in Child-Pugh class B and C (moderate to severe hepatic impairment). Use with caution in Child-Pugh class A; monitor liver function.
Safety and efficacy not established in pediatric patients. No recommended dosage.
Only after menarche. Same dosing as adults: one tablet daily for 21 days, then 7 days off. No weight-based dosing; use standard adult dose.
No specific dosage adjustment recommended; monitor renal function due to age-related decline.
Not indicated for use after menopause. For perimenopausal women, same adult dosing applies; monitor for increased thromboembolic risk.
No black box warning.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives. Risk increases with age (especially >35 years) and number of cigarettes smoked. Women who use COCs should be strongly advised not to smoke.
Dysphagia and esophageal injury risk: Instruct patients to take MODEYSO with water, swallow whole, and not to crush or chew. Advise patients to report signs of esophageal injury.,Embryo-fetal toxicity: Can cause fetal harm. Advise females of reproductive potential to use effective contraception during treatment and for 1 week after the last dose.
Increased risk of thromboembolic disorders (e.g., stroke, MI, DVT, PE),Increased risk of cervical cancer and hepatocellular carcinoma,Elevated blood pressure,Gallbladder disease,Carbohydrate and lipid metabolism effects,Headache, including migraine,Altered menstrual bleeding patterns,Depression,Contact lens intolerance,Hereditary angioedema,Chloasma,Hepatic impairment,Pregnancy (discontinue if pregnancy occurs),Lactation (may decrease milk production)
None known.
Hypersensitivity to any component,Thrombophlebitis or thromboembolic disorder (current or history),Cerebrovascular or coronary artery disease,Known or suspected carcinoma of the breast,Undiagnosed abnormal genital bleeding,Known or suspected pregnancy,Benign or malignant liver tumor (current or history),Severe hepatic impairment (e.g., acute liver disease, decompensated cirrhosis),Active viral hepatitis,Uncontrolled hypertension,Diabetes mellitus with vascular involvement,Headaches with focal neurological symptoms (e.g., migraine with aura) in women >35 years,Major surgery with prolonged immobilization,Smoking in women >35 years
No specific food interactions. Grapefruit juice may increase estrogen levels due to CYP3A4 inhibition, but clinical significance is unknown. Avoid St. John's Wort as it reduces contraceptive efficacy by inducing CYP3A4.
No significant food interactions. Grapefruit juice may increase estrogen levels via CYP3A4 inhibition, but clinical relevance is minimal. Maintain consistent dietary habits to avoid fluctuations in hormone levels.
MODEYSO (mifepristone) is contraindicated in pregnancy for elective abortion. If inadvertently used during early pregnancy, there is a risk of complete abortion. In later pregnancy, it is used as part of medical abortion regimen. No known teratogenic effects if pregnancy continues after failed abortion, but data are limited.
Pregnancy category X. First trimester: Known risk of fetal harm, including cardiovascular defects and limb reduction defects. Second and third trimesters: Increased risk of fetal death, jaundice, and neurodevelopmental issues. Contraindicated in pregnancy.
Mifepristone is excreted into breast milk in low amounts; relative infant dose estimated <1%. M/P ratio approximately 0.5. Consider temporary discontinuation of breastfeeding for 1-2 days after administration.
Excreted in breast milk; M/P ratio not well-defined. May reduce milk production and quality. Use is generally not recommended during breastfeeding due to potential adverse effects on the infant.
No dose adjustment needed for mifepristone in pregnancy as it is used at standard doses for medical abortion. Pharmacokinetic changes in pregnancy (increased volume of distribution) do not necessitate dose alteration due to its single-dose regimen.
Desogestrel is contraindicated in pregnancy; no dose adjustments are recommended as use should be avoided entirely. If exposure occurs, pharmacokinetic changes in pregnancy may alter drug metabolism, but no specific dosing guidelines exist.
MODEYSO (drospirenone/estetrol) is a combined oral contraceptive containing estetrol, a fetal estrogen with unique tissue selectivity. It has a shorter half-life than ethinyl estradiol, potentially reducing thrombotic risk. Monitor potassium levels in patients with renal impairment or those on potassium-sparing diuretics due to drospirenone's antimineralocorticoid activity. Breakthrough bleeding may be more common in the first few cycles. Contraindicated in patients with liver disease, history of DVT/PE, or migraines with aura.
Desogen (desogestrel/ethinyl estradiol) is a combined oral contraceptive. For patients with a history of venous thromboembolism, avoid use. Consider progestin-only alternative if contraindication to estrogen exists. Counsel on increased risk of breakthrough bleeding with missed doses. Monitor blood pressure at baseline and annually.
Take one tablet daily at the same time, with or without food. Do not skip doses.,If you miss a dose, follow the patient leaflet instructions; use backup contraception if needed.,Smoking increases risk of serious cardiovascular side effects; avoid smoking especially if over 35 years old.,Report symptoms of blood clots: sudden leg pain/swelling, chest pain, shortness of breath, or sudden vision changes.,May cause irregular bleeding initially; consult your healthcare provider if bleeding is prolonged or heavy.,Do not take with other medications that increase potassium (e.g., NSAIDs, ACE inhibitors, potassium supplements) without medical advice.
Take one tablet daily at the same time to maintain hormone levels.,If a dose is missed, follow package instructions; use backup contraception if needed.,Report symptoms of blood clots: leg pain/swelling, chest pain, sudden shortness of breath.,Avoid smoking, especially if over 35, due to increased cardiovascular risk.,May cause nausea, breast tenderness, or mood changes; usually resolves within 3 cycles.
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 MODEYSO vs DESOGEN, answered by our medical review team.
MODEYSO is a Combination Oral Contraceptive that works by The mechanism of action of MODEYSO (elacestrant) is not fully elucidated. Elacestrant is an estrogen receptor antagonist that binds to estrogen receptor alpha (ERα) and degrades it, inhibiting estrogen-mediated signaling and tumor growth in ER-positive breast cancer.. DESOGEN is a Combination Oral Contraceptive that works by Progestin (desogestrel) combined with ethinyl estradiol inhibits gonadotropin release, suppressing ovulation. Also increases cervical mucus viscosity, impeding sperm penetration.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between MODEYSO and DESOGEN depend on the specific clinical indication. These are both Combination 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 MODEYSO is: 400 mg orally once daily with food. The standard adult dose of DESOGEN is: One tablet (0.15 mg desogestrel and 0.03 mg ethinyl estradiol) orally once daily for 21 consecutive days, followed by 7 hormone-free 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 MODEYSO and DESOGEN 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. MODEYSO is classified as Category C. MODEYSO (mifepristone) is contraindicated in pregnancy for elective abortion. If inadvertently used during early pregnancy, there is a risk of complete abortion. In later pregnancy. DESOGEN is classified as Category C. Pregnancy category X. First trimester: Known risk of fetal harm, including cardiovascular defects and limb reduction defects. Second and third trimesters: Increased risk of fetal d. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.