Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DEMULEN 1/50-28 vs LARIN 1.5/30
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Combination oral contraceptive: ethinyl estradiol suppresses FSH and LH, preventing ovulation; norethindrone induces endometrial changes and increases cervical mucus viscosity, impeding sperm penetration.
FDA: Prevention of pregnancy,Off-label: Treatment of acne vulgaris, dysmenorrhea, endometriosis-related pain, menstrual irregularity
Prevention of pregnancy
One tablet orally once daily for 28 consecutive days per cycle.
One tablet (norethindrone acetate 1.5 mg, ethinyl estradiol 30 mcg) orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
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: 13-19 hours; Norethindrone: 7-9 hours. Steady-state achieved in ~5-7 days.
Ethinyl estradiol: CYP3A4; undergoes first-pass metabolism with sulfation and glucuronidation. Ethynodiol diacetate: Deacetylated to norethynodrel, then extensively metabolized via reduction and conjugation.
Ethinyl estradiol: primarily CYP3A4; norethindrone: primarily CYP3A4, with some reduction to active metabolites.
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.
Renal (40% as metabolites, <10% unchanged); fecal (50% as metabolites); biliary (minor).
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.
Ethinyl estradiol: 97-98% bound to albumin; Norethindrone: 93-99% bound to SHBG and albumin.
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.
Ethinyl estradiol: 2.5-5 L/kg; Norethindrone: 2-4 L/kg. Indicates extensive tissue distribution.
Oral: ethinylestradiol bioavailability ~40-60% due to first-pass metabolism; ethynodiol diacetate bioavailability ~60-80% after oral administration.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); Norethindrone ~50-60% (first-pass metabolism).
No dosage adjustment required for renal impairment. Use is not recommended in patients with severe renal impairment due to potential adverse effects.
No dose adjustment required in mild to moderate renal impairment (Cr Cl >=30 m L/min). Use contraindicated in severe renal impairment (Cr Cl <30 m L/min) or renal failure due to potential for fluid retention and hyperkalemia.
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.
Contraindicated in Child-Pugh class B or C (moderate to severe hepatic impairment). For Child-Pugh class A, lowest possible effective dose should be used with close monitoring of liver function.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults: one tablet orally once daily for 28 days per cycle.
Post-menarche adolescents: same dosing as adults (one tablet daily for 21 days, then 7 days placebo). Safety and efficacy in pre-menarche girls have not been established.
Not indicated for use in postmenopausal women. No specific dose adjustment recommended for elderly, but consider increased risk of thromboembolic disorders.
Not indicated for postmenopausal women. No specific geriatric dose adjustments; however, consider increased risk of thromboembolic events and cardiovascular disease in women aged >40 years who smoke or have other risk factors.
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.
Cigarette smoking increases risk of serious cardiovascular events. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
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
Cardiovascular disease risk: smoking, hypertension, diabetes, hyperlipidemia,Thromboembolic events: increased risk in surgery, postpartum, or immobilization,Liver disease: discontinue if jaundice develops,Gallbladder disease: increased risk,Glucose intolerance: monitor in diabetics,Blood pressure elevation: monitor periodically,Depression: discontinue if severe
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
Current or history of venous thromboembolism,Cerebrovascular or coronary artery disease,Uncontrolled hypertension,Diabetes with vascular involvement,Known or suspected pregnancy,Liver tumors or active liver disease,Undiagnosed abnormal uterine bleeding,Hypersensitivity to any component,Cigarette smoking in women over 35
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.
Grapefruit juice may increase ethinyl estradiol levels; avoid excessive consumption. No specific dietary restrictions; can be taken with or without food.
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.
First trimester: No consistent evidence of major malformations, but a small increased risk of cardiovascular defects and oral clefts cannot be excluded. Second and third trimesters: Associated with adverse fetal outcomes including low birth weight, preterm delivery, and neonatal withdrawal symptoms. Avoid use during pregnancy due to known risks.
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.
Small amounts of ethinyl estradiol and norethindrone transfer into breast milk, with a milk-to-plasma ratio approximately 0.2-0.3 for norethindrone and <0.1 for ethinyl estradiol. May reduce milk production and composition. Use caution and consider alternative contraception in nursing mothers.
No adjustments; absolute contraindication in pregnancy. Drug should be discontinued immediately upon pregnancy diagnosis. No established safe dose in pregnancy.
Contraindicated in pregnancy; no dose adjustment is applicable as the drug should be discontinued immediately upon confirmed pregnancy.
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.
Larin 1.5/30 is a monophasic combination oral contraceptive containing 1.5 mg norethindrone acetate and 30 mcg ethinyl estradiol. It is indicated for prevention of pregnancy and may also be used for management of acne and menstrual disorders. Advise patients to take at the same time daily to maintain consistent hormone levels. Counsel about breakthrough bleeding, especially during first cycles. Monitor for thrombotic events; use with caution in women with migraine with aura, hypertension, or smoking history over age 35. Effectiveness may be reduced with strong CYP3A4 inducers. Consider alternative contraception if patient is on chronic enzyme-inducing drugs. Use of NSAIDs can increase risk of breakthrough bleeding. Not recommended during breastfeeding or pregnancy.
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.
Take one tablet at the same time each day, with or without food.,If you miss a dose, follow the instructions in the package insert; use backup contraception if needed.,Common side effects include nausea, breast tenderness, headache, and breakthrough bleeding, especially in the first few months.,Seek medical attention if you experience leg pain, chest pain, shortness of breath, severe headache, vision changes, or jaundice.,Do not smoke while taking this medication as it increases the risk of serious cardiovascular side effects.,Inform your healthcare provider of all medications you are taking, including over-the-counter drugs and supplements.,This medication does not protect against sexually transmitted infections; use condoms for STI prevention.
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 DEMULEN 1/50-28 vs LARIN 1.5/30, answered by our medical review team.
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.. LARIN 1.5/30 is a Combination Oral Contraceptive that works by Combination oral contraceptive: ethinyl estradiol suppresses FSH and LH, preventing ovulation; norethindrone induces endometrial changes and increases cervical mucus viscosity, impeding sperm penetration.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DEMULEN 1/50-28 and LARIN 1.5/30 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 DEMULEN 1/50-28 is: One tablet orally once daily for 28 consecutive days per cycle.. The standard adult dose of LARIN 1.5/30 is: One tablet (norethindrone acetate 1.5 mg, ethinyl estradiol 30 mcg) orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.. 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 DEMULEN 1/50-28 and LARIN 1.5/30 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. 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. LARIN 1.5/30 is classified as Category C. First trimester: No consistent evidence of major malformations, but a small increased risk of cardiovascular defects and oral clefts cannot be excluded. Second and third trimesters. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.