Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LO/OVRAL-28 vs DEMULEN 1/50-21
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.
DEMULEN 1/50-21 is a combined oral contraceptive containing ethinyl estradiol and ethynodiol diacetate. Ethinyl estradiol and progestins inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation. Progestins also increase cervical mucus viscosity and alter endometrial receptivity, impeding sperm penetration and implantation.
Prevention of pregnancy,Oral contraceptive
Prevention of pregnancy,Treatment of moderate acne vulgaris (off-label use)
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).
1 tablet (ethinyl estradiol 50 mcg, norethindrone 1 mg) orally once daily for 21 days, followed by 7 days off.
Norgestrel: 20-40 hours; Ethinyl estradiol: 13-27 hours. Steady-state achieved after 3-5 half-lives.
Ethinylestradiol: 13 ± 3 h (biphasic; terminal phase used for dosing interval). Clinical context: steady-state achieved after ~3 days; missed dose may reduce contraceptive efficacy if >36 h.
Hepatic via CYP3A4 for ethinyl estradiol; norgestrel metabolized via reduction and conjugation.
Ethinyl estradiol undergoes first-pass metabolism in the gut wall and liver, with hydroxylation by CYP3A4 and conjugation via glucuronidation and sulfation. Ethynodiol diacetate is rapidly deacetylated to norethindrone, which is metabolized by reduction and conjugation, with CYP3A4 as a minor pathway.
Renal (approx. 50% as metabolites, <1% unchanged); biliary/fecal (approx. 50% as metabolites).
Renal (approx. 50% as metabolites, <1% unchanged), fecal (approx. 40%, largely as ethinylestradiol conjugates), biliary (minor, enterohepatic recirculation of ethinylestradiol)
Norgestrel: 93-99% (primarily SHBG and albumin); Ethinyl estradiol: 97-98% (primarily albumin and SHBG).
Ethinylestradiol: 97-98% bound to serum albumin (primarily) and SHBG; ethynodiol diacetate: >95% bound to albumin and SHBG.
Norgestrel: 3.0 L/kg; Ethinyl estradiol: 4.0 L/kg.
Ethinylestradiol: 2.8-4.3 L/kg (extensive tissue distribution, including breast and reproductive tissues); ethynodiol: 1.5-2.0 L/kg.
Oral: Norgestrel 85-90%; Ethinyl estradiol 38-48% due to first-pass metabolism.
Oral: Ethinylestradiol 38-48% (first-pass metabolism); ethynodiol diacetate ~60% (rapid hydrolysis to active norethindrone).
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 for mild-moderate renal impairment. Avoid use in severe renal impairment or dialysis due to potential fluid retention and electrolyte disturbances.
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 acute or chronic hepatic dysfunction, including Child-Pugh class A, B, or C. Use in mild hepatic impairment not recommended.
Not indicated for use before menarche. For post-menarchal adolescents, the same dosing as adults: one tablet orally daily for 28-day cycles.
Not indicated for use before menarche. For post-menarcheal adolescents, same dosing as adults. Safety and efficacy established in post-pubertal females.
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 after menopause. Risk of thromboembolic events outweighs benefits in women over 35 who smoke or have cardiovascular 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 the risk of serious cardiovascular events from oral contraceptive use. This risk increases with age and with the number of cigarettes smoked, and is quite marked in women over 35 years of age. Women who use oral contraceptives should be strongly advised not to smoke.
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.
Increased risk of thrombotic disorders (venous thromboembolism, stroke, myocardial infarction),Cigarette smoking increases cardiovascular risk, especially in women over 35,Increased risk of hypertension, gallbladder disease, and hepatic neoplasia,Risk of retinal thrombosis; discontinue if unexplained vision loss occurs,May cause fluid retention; use with caution in conditions affected by fluid retention,May induce cholestatic jaundice; discontinue if jaundice develops,May cause carbohydrate and lipid metabolism changes
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.
Known or suspected pregnancy,Current or past history of thrombophlebitis or thromboembolic disorders,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 oral contraceptive use,Hepatic adenoma or carcinoma,Active liver disease (e.g., acute viral hepatitis, decompensated cirrhosis),Hypersensitivity to any component
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.
No specific food interactions. Oral contraceptives may increase caffeine levels; limit caffeine intake if side effects like jitteriness occur. Grapefruit and grapefruit juice do not significantly affect this medication.
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: Use contraindicated due to increased risk of congenital anomalies, particularly cardiovascular defects and limb reduction defects, associated with sex hormones. Second and third trimesters: Avoid due to risk of fetal harm, including masculinization of female fetus with progestins; also associated with increased risk of neonatal jaundice and liver dysfunction.
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 ethynodiol diacetate are excreted in breast milk. M/P ratio not established. Estrogen-progestin combinations may reduce milk production and alter milk composition; use during breastfeeding is generally not recommended. Consider alternative contraception.
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.
Not applicable as use is contraindicated during pregnancy. No pharmacokinetic studies have been conducted to recommend dose adjustments.
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.
DEMULEN 1/50-21 is a monophasic oral contraceptive containing ethinyl estradiol 50 mcg and ethynodiol diacetate 1 mg. Use with caution in patients over 35 who smoke due to increased cardiovascular risk. Monitor for breakthrough bleeding, especially in the first three cycles. Consider drug interactions with rifampin, anticonvulsants, and broad-spectrum antibiotics. Administer at the same time daily to maintain efficacy. The 21-day regimen requires a 7-day pill-free interval. Instruct to start on first day of menses or first Sunday after onset.
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 daily at the same time, starting on the first day of your menstrual period or the first Sunday after your period begins.,Swallow tablet whole with water, with or without food.,After finishing all 21 tablets, wait 7 days before starting a new pack. You will have a withdrawal bleed during this time.,If you miss a tablet by less than 12 hours, take it immediately. If more than 12 hours, take the missed tablet and use backup contraception for 7 days.,Seek emergency medical care for symptoms of blood clots (sudden severe headache, chest pain, shortness of breath, leg pain/swelling), stroke (sudden numbness/weakness, slurred speech), or liver problems (yellowing skin/eyes, dark urine).,Avoid smoking while taking this medication, especially if over age 35, due to increased risk of cardiovascular events.,Inform your healthcare provider about all other medications (including over-the-counter drugs, herbal supplements like St. John's Wort) as they may reduce contraceptive efficacy.,This medication does not protect against HIV or other sexually transmitted infections.
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 DEMULEN 1/50-21, 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.. DEMULEN 1/50-21 is a Combination Oral Contraceptive that works by DEMULEN 1/50-21 is a combined oral contraceptive containing ethinyl estradiol and ethynodiol diacetate. Ethinyl estradiol and progestins inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation. Progestins also increase cervical mucus viscosity and alter endometrial receptivity, impeding sperm penetration and implantation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between LO/OVRAL-28 and DEMULEN 1/50-21 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 DEMULEN 1/50-21 is: 1 tablet (ethinyl estradiol 50 mcg, norethindrone 1 mg) orally once daily for 21 days, followed by 7 days off.. 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 DEMULEN 1/50-21 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. DEMULEN 1/50-21 is classified as Category C. First trimester: Use contraindicated due to increased risk of congenital anomalies, particularly cardiovascular defects and limb reduction defects, associated with sex hormones. Se. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.