Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LO/OVRAL-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 of norgestrel, a progestin, and ethinyl estradiol, an estrogen; suppresses gonadotropin secretion (FSH and LH) primarily via progestational activity, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial development, reducing implantation likelihood.
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,Oral contraceptive
Prevention of pregnancy
One tablet orally once daily for 28 days. Each tablet contains 0.3 mg norgestrel and 0.03 mg ethinyl estradiol. Active tablets (21 days) followed by placebo tablets (7 days).
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.
Norgestrel: 20-40 hours; Ethinyl estradiol: 13-27 hours. Steady-state achieved after 3-5 half-lives.
Ethinyl estradiol: 13-19 hours; Norethindrone: 7-9 hours. Steady-state achieved in ~5-7 days.
Hepatic via CYP3A4 for ethinyl estradiol; norgestrel metabolized via reduction and conjugation.
Ethinyl estradiol: primarily CYP3A4; norethindrone: primarily CYP3A4, with some reduction to active metabolites.
Renal (approx. 50% as metabolites, <1% unchanged); biliary/fecal (approx. 50% as metabolites).
Renal (40% as metabolites, <10% unchanged); fecal (50% as metabolites); biliary (minor).
Norgestrel: 93-99% (primarily SHBG and albumin); Ethinyl estradiol: 97-98% (primarily albumin and SHBG).
Ethinyl estradiol: 97-98% bound to albumin; Norethindrone: 93-99% bound to SHBG and albumin.
Norgestrel: 3.0 L/kg; Ethinyl estradiol: 4.0 L/kg.
Ethinyl estradiol: 2.5-5 L/kg; Norethindrone: 2-4 L/kg. Indicates extensive tissue distribution.
Oral: Norgestrel 85-90%; Ethinyl estradiol 38-48% due to first-pass metabolism.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); Norethindrone ~50-60% (first-pass metabolism).
No dosage adjustment required for renal impairment. However, use with caution in patients with renal dysfunction due to potential fluid retention.
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 Class B or C cirrhosis. For Child-Pugh Class A, use with caution; limited data, but no specific dose adjustment recommended.
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-menarchal adolescents, the same dosing as adults: one tablet orally daily for 28-day cycles.
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 in postmenopausal women. No geriatric-specific dosing; not for use in elderly due to lack of need for contraception after menopause.
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 contraceptive use. 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 (e.g., venous thromboembolism, stroke, myocardial infarction); hepatic neoplasia; hypertension; gallbladder disease; carbohydrate/lipid effects; ocular lesions; breakthrough bleeding; missed periods; ectopic pregnancy risk; lactation; depression.
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; history of deep vein thrombosis or pulmonary embolism; cerebrovascular or coronary artery disease; known or suspected breast carcinoma; 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 does not notably affect ethinyl estradiol levels, but consistent intake is recommended to maintain uniform hormone levels. Avoid excessive alcohol consumption as it may impair liver function and alter hormone metabolism.
Grapefruit juice may increase ethinyl estradiol levels; avoid excessive consumption. No specific dietary restrictions; can be taken with or without food.
First trimester: No known association with major congenital anomalies, but small increased risk of cardiovascular defects and limb reduction defects reported in some studies. Second/third trimesters: Use not recommended due to potential adverse effects on fetal development including virilization of female fetus and hepatic adenoma; contraindicated in known 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.
Enters breast milk in small amounts; estrogen and progestin may reduce milk production and composition. M/P ratio not established. Generally avoided during breastfeeding due to theoretical risks; low-dose progestin-only contraception preferred.
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.
Contraindicated in pregnancy; no dose adjustments applicable as use is not recommended. Pharmacokinetic changes in pregnancy include increased clearance of ethinyl estradiol and norgestrel, but pregnancy contraindication precludes dose modification.
Contraindicated in pregnancy; no dose adjustment is applicable as the drug should be discontinued immediately upon confirmed pregnancy.
LO/OVRAL-28 is a combination oral contraceptive containing norgestrel and ethinyl estradiol. It is indicated for pregnancy prevention. The 28-day regimen includes 21 active pills and 7 placebo pills. Counsel patients to take at the same time daily. Breakthrough bleeding is common in the first few cycles. If a dose is missed, follow the specific package instructions. Anti-infectives like rifampin may reduce efficacy; additional contraception is recommended.
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 each day.,If you miss a pill, refer to the package insert for instructions; use backup contraception if needed.,Common side effects include nausea, breast tenderness, and spotting, which usually improve after a few cycles.,Smoking increases risk of serious cardiovascular side effects; do not smoke while taking this medication.,Inform your healthcare provider if you have a history of blood clots, migraines with aura, or liver disease.
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 LO/OVRAL-28 vs LARIN 1.5/30, answered by our medical review team.
LO/OVRAL-28 is a Combination Oral Contraceptive that works by Combination of norgestrel, a progestin, and ethinyl estradiol, an estrogen; suppresses gonadotropin secretion (FSH and LH) primarily via progestational activity, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial development, reducing implantation likelihood.. 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 LO/OVRAL-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 LO/OVRAL-28 is: One tablet orally once daily for 28 days. Each tablet contains 0.3 mg norgestrel and 0.03 mg ethinyl estradiol. Active tablets (21 days) followed by placebo tablets (7 days).. 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 LO/OVRAL-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. LO/OVRAL-28 is classified as Category C. First trimester: No known association with major congenital anomalies, but small increased risk of cardiovascular defects and limb reduction defects reported in some studies. Secon. 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.