Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
MODICON 28 vs DEMULEN 1/50-28
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; norethindrone induces changes in cervical mucus and endometrium, impeding sperm penetration and implantation.
Combination oral contraceptive: Ethinyl estradiol and ethynodiol diacetate suppress gonadotropin secretion (LH, FSH) via negative feedback, inhibiting ovulation. Ethynodiol diacetate also increases cervical mucus viscosity and induces endometrial changes.
Prevention of pregnancy
FDA: Prevention of pregnancy,Off-label: Treatment of acne vulgaris, dysmenorrhea, endometriosis-related pain, menstrual irregularity
One tablet orally once daily, each tablet containing 0.035 mg ethinyl estradiol and 0.4 mg norethindrone, taken at the same time each day for 21 days followed by 7 days of placebo tablets.
One tablet orally once daily for 28 consecutive days per cycle.
Terminal elimination half-life: 13-19 hours (mean 16 hours) for norethindrone; steady state achieved within 5-7 days.
Ethinylestradiol: terminal elimination half-life ~13-27 hours (mean ~17 hours); ethynodiol diacetate (as norethindrone): terminal elimination half-life ~8-11 hours; clinical context: achieved steady-state within 5-10 days; accumulation not significant due to dose interval.
Ethinyl estradiol undergoes hepatic metabolism via CYP3A4; norethindrone is metabolized primarily via reduction and conjugation, with involvement of CYP3A4.
Ethinyl estradiol: CYP3A4; undergoes first-pass metabolism with sulfation and glucuronidation. Ethynodiol diacetate: Deacetylated to norethynodrel, then extensively metabolized via reduction and conjugation.
Renal: 50-60% as metabolites, fecal: 40-50% as metabolites, with enterohepatic circulation; less than 1% unchanged in urine.
Ethinylestradiol and ethynodiol diacetate are extensively metabolized; urinary excretion accounts for ~40% of ethinylestradiol metabolites and ~50-60% of ethynodiol diacetate metabolites; fecal excretion accounts for ~30% of ethinylestradiol metabolites and ~35% of ethynodiol diacetate metabolites; biliary excretion contributes to enterohepatic circulation.
Norethindrone: 61-67% bound to SHBG and albumin (55% to SHBG, 45% to albumin); ethinyl estradiol: 97-98% bound to albumin, not bound to SHBG.
Ethinylestradiol: >97% bound, primarily to albumin, with ~2% bound to sex hormone-binding globulin (SHBG); ethynodiol diacetate (as norethindrone): ~95% bound, primarily to albumin and SHBG.
Norethindrone: Vd approximately 4 L/kg (range 2-6 L/kg), indicating extensive tissue distribution; ethinyl estradiol: Vd approximately 2-4 L/kg.
Ethinylestradiol: Vd ~2-4 L/kg; distributes extensively into body tissues; ethynodiol diacetate (as norethindrone): Vd ~4 L/kg; indicates wide distribution including reproductive tissues.
Oral norethindrone: 45-65% due to first-pass metabolism; ethinyl estradiol: 38-48% oral bioavailability.
Oral: ethinylestradiol bioavailability ~40-60% due to first-pass metabolism; ethynodiol diacetate bioavailability ~60-80% after oral administration.
No dose adjustment required for mild to moderate renal impairment. Insufficient data for severe renal impairment (Cr Cl <30 m L/min); consider alternative contraception due to potential hormonal accumulation.
No dosage adjustment required for renal impairment. Use is not recommended in patients with severe renal impairment due to potential adverse effects.
Contraindicated in acute hepatic disease or severe hepatic impairment (Child-Pugh class C). Use with caution in mild to moderate impairment (Child-Pugh A or B); monitor liver function; consider alternative contraception.
Contraindicated in patients with Child-Pugh C cirrhosis. For Child-Pugh A or B, use is generally not recommended; if used, monitor closely for adverse effects.
Not indicated for use before menarche. For post-menarche adolescents: same dosing as adults (one tablet daily). Safety and efficacy established in females of reproductive age.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults: one tablet orally once daily for 28 days per cycle.
Not indicated for use in postmenopausal women. Efficacy for contraception not applicable; no dosing recommendations for this population.
Not indicated for use in postmenopausal women. No specific dose adjustment recommended for elderly, but consider increased risk of thromboembolic disorders.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives. Risk increases with age and smoking intensity, especially in women over 35. Women should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events (e.g., myocardial infarction, stroke, thromboembolism). Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
Thrombotic disorders (thrombophlebitis, venous thromboembolism, cerebrovascular disease, myocardial infarction),Hepatic disease (jaundice, hepatic adenomas),Hypertension,Gallbladder disease,Carbohydrate and lipid effects,Ocular lesions (e.g., retinal thrombosis),Headache (including migraine),Menstrual irregularities/breakthrough bleeding,Depression,Reduced efficacy with enzyme-inducing drugs,Bone mineral density changes,Hereditary angioedema
Thromboembolic disorders (DVT, PE, stroke, MI),Hepatic neoplasia (benign/malignant liver tumors),Increased risk of gallbladder disease,Hypertension,Carbohydrate/lipid metabolic effects,Ocular disturbances (retinal thrombosis, optic neuritis),Depression,Fetal harm if used during pregnancy
Known or suspected pregnancy,Current or past history of thrombophlebitis or thromboembolic disorders,Cerebrovascular disease,Coronary artery disease,Known or suspected carcinoma of the breast,Carcinoma of the endometrium or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior oral contraceptive use,Hepatic adenomas or carcinomas,Known or suspected liver disease,Heavy smoking (≥15 cigarettes/day) and age ≥35,Hypersensitivity to any component
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease,Known or suspected breast cancer,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,Known or suspected pregnancy,Hypersensitivity to any component
Grapefruit and grapefruit juice may increase ethinyl estradiol levels by inhibiting CYP3A4, but the effect is variable; advise caution or avoid concurrent intake. No other significant food interactions are known. High-fat meals may delay absorption but do not reduce overall efficacy.
No significant food interactions. Grapefruit juice may increase estrogen levels, but clinical significance is unclear. Maintain consistent intake of vitamin C-rich foods as they may increase estrogen absorption. Avoid St. John's wort, which reduces contraceptive efficacy.
FDA Pregnancy Category X. First trimester: increased risk of neural tube defects, congenital heart defects, and other malformations due to estrogen/progestin exposure. Second and third trimesters: associated with elevated risks of preterm birth, low birth weight, and neonatal complications. Use contraindicated in pregnancy.
Contraindicated in pregnancy. First trimester: increased risk of neural tube defects, congenital heart defects, and limb reduction defects from progestins. Second and third trimesters: association with masculinization of female fetus, adrenal suppression, and possible long-term metabolic effects. Estrogen component may increase risk of VACTERL anomalies.
Safety: Small amounts of ethinyl estradiol and progestin (norethindrone) are excreted in breast milk. M/P ratio: Not established for this specific combination; ethinyl estradiol M/P ~0.2-0.4. May reduce milk production and alter milk composition. Not recommended during breastfeeding; alternative contraception advised.
Contraindicated during breastfeeding. Estrogens reduce milk production and quality. M/P ratio not established; ethinyl estradiol and norgestrel are excreted in breast milk in small amounts, potentially causing adverse effects in the infant.
No dose adjustment required as drug is contraindicated in pregnancy. Pharmacokinetic changes during pregnancy (increased hepatic metabolism, volume of distribution) are not relevant due to contraindication. If inadvertent exposure occurs, discontinue drug.
No adjustments; absolute contraindication in pregnancy. Drug should be discontinued immediately upon pregnancy diagnosis. No established safe dose in pregnancy.
MODICON 28 is a combined oral contraceptive containing ethinyl estradiol 0.035 mg and norethindrone 0.5 mg. It is crucial to counsel patients on the importance of taking the pill at the same time daily to maintain consistent hormone levels. The regimen includes 21 active pills followed by 7 placebo pills; during the placebo week, withdrawal bleeding typically occurs. For missed pills: if one pill is missed, take it as soon as remembered and continue schedule; if two or more are missed, take the most recent missed pill and use backup contraception for 7 days. Consider potential drug interactions with antibiotics, anticonvulsants (e.g., carbamazepine, phenytoin), and St. John's wort, which may reduce contraceptive efficacy. Smoking increases risk of serious cardiovascular events, especially in women over 35. Monitor blood pressure at baseline and periodically. Caution in patients with history of thromboembolic disorders, migraine with aura, hypertension, or liver disease.
Demulen 1/50-28 is a monophasic combined oral contraceptive containing ethinyl estradiol 50 mcg and ethynodiol diacetate 1 mg. Due to the 50 mcg estrogen dose, it carries an increased risk of venous thromboembolism compared to lower-dose pills; avoid in patients with migraine with aura, hypertension >160/100 mm Hg, or age >35 who smoke. The 28-day pack includes 21 active pills and 7 placebo pills; breakthrough bleeding is more common with higher estrogen. Caution with hepatic enzyme inducers like rifampin or anticonvulsants may reduce efficacy.
Take one pill daily at the same time, preferably after an evening meal or at bedtime to minimize nausea.,The pack contains 21 active (hormone) pills and 7 placebo (reminder) pills; withdrawal bleeding usually occurs during the placebo week.,If you miss a pill, refer to the package insert instructions; use backup contraception (e.g., condoms) if needed.,Use additional non-hormonal contraception during the first 7 days of starting the pill if switching from another method.,Seek immediate medical attention if you experience symptoms of a blood clot, such as sudden leg pain or swelling, chest pain, shortness of breath, or severe headache.,This medication does not protect against sexually transmitted infections (STIs); use condoms for STI prevention.,Inform your healthcare provider of all medications and supplements you take, especially antibiotics, anticonvulsants, and St. John's wort.,Avoid smoking, especially if over 35, as it increases the risk of serious side effects.
Take one pill daily at the same time, preferably with food to reduce nausea.,The first 7 days of the first cycle require a backup contraceptive method if not starting on day 1 of menses.,Missed pill: if one active pill is missed, take it as soon as remembered and continue; if two or more active pills are missed, take the last missed pill, skip the others, use backup for 7 days, and consider emergency contraception.,Smoking increases risk of serious cardiovascular side effects; avoid smoking, especially if over 35.,Report symptoms of blood clots: sudden leg pain/swelling, chest pain, shortness of breath, or severe headache.,The 7 placebo pills are for withdrawal bleeding; start next pack on time regardless of bleeding.
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 MODICON 28 vs DEMULEN 1/50-28, answered by our medical review team.
MODICON 28 is a Combination Oral Contraceptive that works by Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; norethindrone induces changes in cervical mucus and endometrium, impeding sperm penetration and implantation.. DEMULEN 1/50-28 is a Combination Oral Contraceptive that works by Combination oral contraceptive: Ethinyl estradiol and ethynodiol diacetate suppress gonadotropin secretion (LH, FSH) via negative feedback, inhibiting ovulation. Ethynodiol diacetate also increases cervical mucus viscosity and induces endometrial changes.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between MODICON 28 and DEMULEN 1/50-28 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 MODICON 28 is: One tablet orally once daily, each tablet containing 0.035 mg ethinyl estradiol and 0.4 mg norethindrone, taken at the same time each day for 21 days followed by 7 days of placebo tablets.. The standard adult dose of DEMULEN 1/50-28 is: One tablet orally once daily for 28 consecutive days per cycle.. 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 MODICON 28 and DEMULEN 1/50-28 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. MODICON 28 is classified as Category C. FDA Pregnancy Category X. First trimester: increased risk of neural tube defects, congenital heart defects, and other malformations due to estrogen/progestin exposure. Second and t. DEMULEN 1/50-28 is classified as Category C. Contraindicated in pregnancy. First trimester: increased risk of neural tube defects, congenital heart defects, and limb reduction defects from progestins. Second and third trimest. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.