Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LO/OVRAL 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 estrogen-progestin oral contraceptive; suppresses gonadotropin release, primarily FSH and LH, inhibiting ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial receptivity.
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,Dysfunctional uterine bleeding,Hormonal contraception
Prevention of pregnancy
One tablet (30 mcg ethinyl estradiol, 0.3 mg norgestrel) orally once daily for 28-day cycle (21 active, 7 placebo).
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 (levonorgestrel): 11-45 hours (mean ~24 hours); ethinyl estradiol: 7-21 hours (mean ~14 hours). Half-life increases slightly with repeated dosing due to saturable metabolism.
Ethinyl estradiol: 13-19 hours; Norethindrone: 7-9 hours. Steady-state achieved in ~5-7 days.
Ethinyl estradiol is primarily metabolized by CYP3A4; norgestrel is metabolized via reduction and conjugation; both undergo first-pass metabolism.
Ethinyl estradiol: primarily CYP3A4; norethindrone: primarily CYP3A4, with some reduction to active metabolites.
Urine (50-60% as conjugated metabolites), feces (30-40% as metabolites), enterohepatic recirculation present.
Renal (40% as metabolites, <10% unchanged); fecal (50% as metabolites); biliary (minor).
Levonorgestrel: 97-99% (primarily to sex hormone-binding globulin, SHBG, and albumin); ethinyl estradiol: 97-98% (primarily to albumin, increases SHBG levels).
Ethinyl estradiol: 97-98% bound to albumin; Norethindrone: 93-99% bound to SHBG and albumin.
Levonorgestrel: 1.0-1.3 L/kg; ethinyl estradiol: 2.3-3.0 L/kg. Reflects extensive tissue distribution and binding.
Ethinyl estradiol: 2.5-5 L/kg; Norethindrone: 2-4 L/kg. Indicates extensive tissue distribution.
Oral: levonorgestrel ~100% (first-pass metabolism <10%), ethinyl estradiol 38-48% due to first-pass conjugation in gut wall and liver.
Oral: Ethinyl estradiol ~40-50% (first-pass metabolism); Norethindrone ~50-60% (first-pass metabolism).
No dosage adjustment required for mild to moderate impairment. Not recommended in severe renal impairment (e GFR <30 m L/min/1.73m²) due to limited data.
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 Child-Pugh class B or C (active liver disease, jaundice, or impaired synthetic function). Use discontinued if hepatic function deteriorates.
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.
Post-menarche adolescents: Same dosing as adults (30 mcg ethinyl estradiol/0.3 mg norgestrel daily). Not indicated pre-menarche.
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 postmenopausal women. Higher risk of thromboembolism and cardiovascular events in women >40 years, especially if smoking or other risk factors.
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 oral contraceptive use; risk increases with age (especially in women over 35 years) and with heavy smoking (≥15 cigarettes/day); 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.
Increased risk of thromboembolic disorders (e.g., MI, stroke, VTE); hepatic adenoma; risk of breast cancer; hypertension; gallbladder disease; impaired glucose tolerance; cholestatic jaundice; ocular lesions (e.g., retinal thrombosis); use in pregnancy; fluid retention; 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
Thrombophlebitis or thromboembolic disorders; cerebrovascular or coronary artery disease; known or suspected breast carcinoma; estrogen-dependent neoplasia; undiagnosed abnormal genital bleeding; known or suspected pregnancy; hepatic adenoma or malignancy; cholestatic jaundice of pregnancy or jaundice with prior pill use; active liver disease; hypersensitivity to any component; cigarette smoking in women ≥35 years; uncontrolled hypertension; diabetes with vascular involvement; headaches with focal neurological symptoms; major surgery with prolonged immobilization.
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 ethinyl estradiol levels via CYP3A4 inhibition, but clinical relevance is minimal with low-dose pills. Avoid using St. John's wort, which may decrease contraceptive efficacy.
Grapefruit juice may increase ethinyl estradiol levels; avoid excessive consumption. No specific dietary restrictions; can be taken with or without food.
First trimester: No increased risk of major malformations based on epidemiological studies. Second/third trimesters: Exposure may increase risk of fetal liver tumors (rare) and possibly cardiovascular malformations; contraindicated due to feminization of male fetus. Post-market reports: Possible association with neonatal jaundice, cholestasis, and transient hormonal effects.
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 due to potential adverse effects on milk production and infant hormonal balance. M/P ratio not established; ethinyl estradiol and norgestrel are excreted into human milk in small amounts but insufficient data on infant exposure.
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 during pregnancy; drug is contraindicated after confirmed pregnancy. Pregnancy-induced changes in pharmacokinetics (increased clearance, volume of distribution) may reduce efficacy, but use is not recommended.
Contraindicated in pregnancy; no dose adjustment is applicable as the drug should be discontinued immediately upon confirmed pregnancy.
Lo/Ovral is a low-dose combined oral contraceptive containing ethinyl estradiol and norgestrel. Not recommended for use in women with BMI > 35 kg/m² due to increased thromboembolic risk. Advise consistent daily timing within a 3-hour window to maintain efficacy. Missed pill management: if one pill is missed >12 hours late, take missed pill and continue with next pill at normal time; if two or more pills are missed, take the most recent missed pill and use backup contraception for 7 days. Consider CYP3A4 inducers (e.g., rifampin, St. John's wort) that 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 tablet daily at the same time every day.,Do not skip pills; if you miss a pill, follow the missed pill instructions in the package insert.,Use backup contraception (e.g., condoms) if you vomit or have severe diarrhea within 4 hours of taking a pill.,Avoid smoking, especially if over 35 years old, as it increases risk of serious cardiovascular side effects.,Tell your healthcare provider about all medications and supplements you take, as some may interfere with birth control effectiveness.,Lo/Ovral does not protect against HIV or other sexually transmitted infections.,Store at room temperature away from moisture and heat.
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 vs LARIN 1.5/30, answered by our medical review team.
LO/OVRAL is a Combination Oral Contraceptive that works by Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release, primarily FSH and LH, inhibiting ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial receptivity.. 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 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 is: One tablet (30 mcg ethinyl estradiol, 0.3 mg norgestrel) orally once daily for 28-day cycle (21 active, 7 placebo).. 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 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 is classified as Category C. First trimester: No increased risk of major malformations based on epidemiological studies. Second/third trimesters: Exposure may increase risk of fetal liver tumors (rare) and pos. 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.