Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LARIN 24 FE vs DEMULEN 1/35-28
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 containing ethinyl estradiol (estrogen) and norethindrone (progestin). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Increases cervical mucus viscosity, impeding sperm penetration, and alters endometrial structure, reducing implantation likelihood.
Combination estrogen-progestin contraceptive; suppresses gonadotropin release, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial receptivity.
Prevention of pregnancy,Moderate acne vulgaris (in females ≥15 years who have onset of menarche and desire an oral contraceptive for contraception)
Prevention of pregnancy
One tablet (20 mcg ethinyl estradiol / 1 mg norethindrone acetate) orally once daily for 24 days, followed by 1 iron-containing placebo tablet (75 mg ferrous fumarate) orally once daily for 4 days.
One tablet (contains 1 mg ethynodiol diacetate and 35 mcg ethinyl estradiol) orally once daily at the same time each day for 21 days, followed by 7 days of placebo or no tablets.
Ethinyl estradiol: ~13 hours (range 7–20); norethindrone: ~8 hours (range 5–14). Half-life supports once-daily dosing; steady state achieved within 5–7 days.
Ethinyl estradiol: 17.4 ± 5.6 h (terminal); norethindrone: 10.9 ± 1.6 h (terminal); clinically, steady-state achieved within 5-7 days.
Ethinyl estradiol: CYP3A4; undergoes first-pass metabolism in liver and gut wall, sulfation and glucuronidation. Norethindrone: primarily hepatic reduction and conjugation; metabolized via CYP3A4 and CYP2C9.
Ethinylestradiol undergoes hepatic metabolism via CYP3A4; norethindrone undergoes reduction and conjugation in the liver.
Ethinyl estradiol: 40% renal, 60% fecal; norethindrone: 40% renal, 60% fecal.
Renal 50% (metabolites), fecal 50% (biliary elimination of conjugates).
Ethinyl estradiol: 98% bound to albumin and SHBG; norethindrone: 93% bound to albumin and SHBG.
Ethinyl estradiol: 97-98% bound to albumin; norethindrone: 93% bound to albumin and SHBG.
Ethinyl estradiol: 2.3–4.0 L/kg; norethindrone: 3.0–4.5 L/kg. Indicates extensive tissue distribution.
Ethinyl estradiol: 2.3-4.3 L/kg; norethindrone: 4.4 L/kg; indicates extensive tissue distribution.
Ethinyl estradiol: ~45% (range 38–48%); norethindrone: ~65% (range 60–70%). First-pass metabolism reduces oral bioavailability.
Ethinyl estradiol: 40-45% (oral; first-pass metabolism); norethindrone: 64-67% (oral).
No specific dose adjustment recommended; use with caution in patients with renal impairment. No GFR-based guidelines established.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure.
Contraindicated in patients with hepatic adenomas, acute hepatitis, or decompensated cirrhosis (Child-Pugh class B or C). No dose adjustment recommended in mild hepatic impairment (Child-Pugh class A) but use with caution.
Contraindicated in acute or chronic hepatic dysfunction, including Child-Pugh class A, B, or C. Avoid use if liver function tests are abnormal.
Safety and efficacy established for use after menarche; dose same as adult: one active tablet daily for 24 days then one placebo tablet daily for 4 days. No weight-based dosing.
Not indicated for use before menarche. For postmenarchal adolescents, use same dosing as adults (one tablet orally once daily).
Not indicated for postmenopausal women; no specific dose adjustment recommended, but consider increased risk of thromboembolic events and cardiovascular disease in older women.
Not indicated for use in postmenopausal women.
Cigarette smoking increases risk of serious cardiovascular events (e.g., stroke, myocardial infarction, thromboembolism) from oral contraceptive use. Risk increases with age and number of cigarettes smoked, particularly in women >35 years. Women who use oral contraceptives should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events. Risk increases with age and smoking intensity. Women over 35 who smoke should not use this product.
Thromboembolic disorders (e.g., DVT, PE, stroke, MI),Cigarette smoking (increases cardiovascular risk),Hypertension,Gallbladder disease,Hepatic neoplasia (liver tumors),Carbohydrate/lipid metabolism effects (hyperglycemia, hypertriglyceridemia),Headache (including migraine),Uterine bleeding irregularities,Ocular lesions (e.g., retinal thrombosis),Depression,Pregnancy and postpartum use,Lactation (may reduce milk production)
Increased risk of thromboembolic disorders,Cerebrovascular disease,Myocardial infarction,Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate/lipid effects,Headache,Uterine bleeding,Ocular lesions,Depression
Known or suspected pregnancy,Current or past history of thrombophlebitis or thromboembolic disorders,Cerebrovascular or coronary artery disease,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 adenomas or carcinomas,Known or suspected hypersensitivity to any component of the product,Heavy smoking (>15 cigarettes/day) and age >35 years
Known or suspected pregnancy,Current or past thrombosis,Cerebrovascular or coronary artery disease,Valvular heart disease with complications,Severe hypertension,Diabetes with vascular involvement,Headaches with focal neurological symptoms,Major surgery with prolonged immobilization,Known or suspected breast cancer,Endometrial cancer or other estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenomas or carcinomas,Active liver disease,Known hypersensitivity to any component
No significant food interactions. Grapefruit juice may increase estrogen levels, but effect is minimal. Take with food if nausea occurs.
No significant food interactions. Grapefruit juice has minimal effect on ethinyl estradiol; no restriction needed. Avoid excessive alcohol, which may impair adherence or increase liver enzymes. St. John's wort reduces contraceptive efficacy and should be avoided.
LARIN 24 FE (norethindrone/ethinyl estradiol) is contraindicated in pregnancy. First trimester exposure is not associated with major malformations based on epidemiological data, but there is a small increased risk of cardiovascular defects. Second and third trimester exposure may cause fetal harm, including feminization of male fetuses (mild hypospadias) and potential for other teratogenic effects. Use is not recommended during pregnancy.
First trimester: Increased risk of neural tube defects, cardiovascular anomalies, and oral clefts (OR ~1.3-1.6). Second/third trimester: Androgenization of female fetus (clitoromegaly, labial fusion) due to progestin component; possible association with hypospadias in males with first-trimester exposure. Avoid use in pregnancy.
Combined hormonal contraceptives like LARIN 24 FE are generally not recommended during breastfeeding due to potential suppression of milk production and excretion of small amounts of hormones into breast milk. The M/P ratio is not well established; estrogens and progestins are present in milk at low concentrations. Use in lactating women should be avoided, especially in early postpartum period. Alternative contraception methods are preferred.
Excreted in breast milk; estimated infant dose <1% of maternal dose. M/P ratio not available for ethinyl estradiol/ethynodiol diacetate. May reduce milk production and quality. Use only if benefits outweigh risks; lowest effective dose recommended.
No dose adjustments are applicable as LARIN 24 FE is contraindicated during pregnancy. Pharmacokinetic changes in pregnancy (increased clearance of steroids) are not relevant due to contraindication. Therapy should be discontinued immediately if pregnancy occurs.
Contraindicated in pregnancy; no dose adjustment applicable. If inadvertently used, discontinue immediately.
LARIN 24 FE is a combined hormonal contraceptive containing ethinyl estradiol and norethindrone. It uses a 24/4 regimen with 24 active pills and 4 iron-containing placebo pills. The iron (ferrous fumarate) in placebo pills is not contraceptive and serves to reduce iron-deficiency anemia risk. Prescribe for contraception, acne, or menstrual disorders. Monitor for VTE risk, especially in smokers over 35. Consider drug interactions with CYP3A4 inducers (e.g., rifampin, certain anticonvulsants) which reduce efficacy. Breakthrough bleeding is common in the first 3 cycles.
DEMULEN 1/35-28 (ethinyl estradiol 35 mcg + ethynodiol diacetate 1 mg) is a monophasic combined oral contraceptive. Its progestin has mild androgenic activity, which may be less favorable for acne-prone patients compared to third-generation pills. The 28-day pack includes 21 active pills and 7 inert pills. Counsel patients to take at the same time daily; missed pills increase breakthrough bleeding and pregnancy risk. It may be used off-label for cycle control in patients without contraindications.
Take one pill daily at the same time; missing pills increases pregnancy risk.,Active pills are light blue; placebo pills are brown and contain iron.,Use backup contraception for the first 7 days if starting after Day 5 of menstrual cycle.,If you miss two or more active pills, take the last missed pill and use backup contraception for 7 days.,Smoking while on this pill increases risk of serious cardiovascular side effects; do not smoke.,Report signs of blood clots: sudden leg pain/swelling, chest pain, shortness of breath, or vision changes.,Iron in placebo pills helps prevent anemia but does not provide contraception.
Take one pill daily at the same time, preferably after dinner to reduce nausea.,If you miss one pill, take it as soon as remembered; if missed more than one, use backup contraception for 7 days.,Smoking increases risk of blood clots; especially dangerous if over 35 and smokes.,Some antibiotics (e.g., rifampin) and antiseizure medications may reduce effectiveness.,Report any signs of blood clot: sudden leg pain/swelling, chest pain, shortness of breath, or sudden severe headache.,Breakthrough bleeding is common in first 3 cycles; if persistent, contact your healthcare provider.,Do not use if pregnant; if pregnancy occurs, stop immediately.
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 LARIN 24 FE vs DEMULEN 1/35-28, answered by our medical review team.
LARIN 24 FE is a Combination Oral Contraceptive that works by Combination oral contraceptive containing ethinyl estradiol (estrogen) and norethindrone (progestin). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Increases cervical mucus viscosity, impeding sperm penetration, and alters endometrial structure, reducing implantation likelihood.. DEMULEN 1/35-28 is a Combination Oral Contraceptive that works by Combination estrogen-progestin contraceptive; suppresses gonadotropin release, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial receptivity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between LARIN 24 FE and DEMULEN 1/35-28 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 LARIN 24 FE is: One tablet (20 mcg ethinyl estradiol / 1 mg norethindrone acetate) orally once daily for 24 days, followed by 1 iron-containing placebo tablet (75 mg ferrous fumarate) orally once daily for 4 days.. The standard adult dose of DEMULEN 1/35-28 is: One tablet (contains 1 mg ethynodiol diacetate and 35 mcg ethinyl estradiol) orally once daily at the same time each day for 21 days, followed by 7 days of placebo or no 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 LARIN 24 FE and DEMULEN 1/35-28 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. LARIN 24 FE is classified as Category C. LARIN 24 FE (norethindrone/ethinyl estradiol) is contraindicated in pregnancy. First trimester exposure is not associated with major malformations based on epidemiological data, bu. DEMULEN 1/35-28 is classified as Category C. First trimester: Increased risk of neural tube defects, cardiovascular anomalies, and oral clefts (OR ~1.3-1.6). Second/third trimester: Androgenization of female fetus (clitoromeg. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.