Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
MODICON 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 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 suppresses FSH and LH, preventing ovulation; norethindrone induces endometrial changes and increases cervical mucus viscosity, impeding sperm penetration.
Prevention of pregnancy
Prevention of pregnancy
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 (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.
Terminal elimination half-life: 13-19 hours (mean 16 hours) for norethindrone; steady state achieved within 5-7 days.
Ethinyl estradiol: 13-19 hours; Norethindrone: 7-9 hours. Steady-state achieved in ~5-7 days.
Ethinyl estradiol undergoes hepatic metabolism via CYP3A4; norethindrone is metabolized primarily via reduction and conjugation, with involvement of CYP3A4.
Ethinyl estradiol: primarily CYP3A4; norethindrone: primarily CYP3A4, with some reduction to active metabolites.
Renal: 50-60% as metabolites, fecal: 40-50% as metabolites, with enterohepatic circulation; less than 1% unchanged in urine.
Renal (40% as metabolites, <10% unchanged); fecal (50% as metabolites); biliary (minor).
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.
Ethinyl estradiol: 97-98% bound to albumin; Norethindrone: 93-99% bound to SHBG and albumin.
Norethindrone: Vd approximately 4 L/kg (range 2-6 L/kg), indicating extensive tissue distribution; ethinyl estradiol: Vd approximately 2-4 L/kg.
Ethinyl estradiol: 2.5-5 L/kg; Norethindrone: 2-4 L/kg. Indicates extensive tissue distribution.
Oral norethindrone: 45-65% due to first-pass metabolism; ethinyl estradiol: 38-48% oral bioavailability.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); Norethindrone ~50-60% (first-pass metabolism).
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 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 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 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 post-menarche adolescents: same dosing as adults (one tablet daily). Safety and efficacy established in females of reproductive age.
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. Efficacy for contraception not applicable; no dosing recommendations for this population.
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 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. 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
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
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
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
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.
Grapefruit juice may increase ethinyl estradiol levels; avoid excessive consumption. No specific dietary restrictions; can be taken with or without food.
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.
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.
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.
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 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.
Contraindicated in pregnancy; no dose adjustment is applicable as the drug should be discontinued immediately upon confirmed 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.
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 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 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 MODICON 28 vs LARIN 1.5/30, 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.. 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 MODICON 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 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 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 MODICON 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. 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. 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.