Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LO LOESTRIN FE vs DEMULEN 1/50-28
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination of ethinyl estradiol and norethindrone acetate suppresses gonadotropin-releasing hormone (Gn RH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary, thereby inhibiting ovulation. The progestin component thickens cervical mucus, impeding sperm penetration, and alters endometrial receptivity. Ferrous fumarate provides supplemental iron.
Combination oral contraceptive: Ethinyl estradiol and ethynodiol diacetate suppress gonadotropin secretion (LH, FSH) via negative feedback, inhibiting ovulation. Ethynodiol diacetate also increases cervical mucus viscosity and induces endometrial changes.
Oral contraception,Treatment of heavy menstrual bleeding (off-label),Dysmenorrhea (off-label),Acne vulgaris (off-label),Polycystic ovary syndrome (off-label)
FDA: Prevention of pregnancy,Off-label: Treatment of acne vulgaris, dysmenorrhea, endometriosis-related pain, menstrual irregularity
One tablet orally once daily. Each tablet contains norethindrone acetate 1 mg and ethinyl estradiol 10 mcg (24 active tablets) followed by ferrous fumarate 75 mg (2 inactive tablets).
One tablet orally once daily for 28 consecutive days per cycle.
Norethindrone: ~8 hours (range 5–12 h); Ethinyl estradiol: ~14 hours (range 10–20 h). Terminal half-life supports once-daily dosing with steady-state reached within 7–14 days.
Ethinylestradiol: terminal elimination half-life ~13-27 hours (mean ~17 hours); ethynodiol diacetate (as norethindrone): terminal elimination half-life ~8-11 hours; clinical context: achieved steady-state within 5-10 days; accumulation not significant due to dose interval.
Ethinyl estradiol is metabolized primarily via CYP3A4, with hydroxylation and conjugation pathways. Norethindrone acetate is rapidly hydrolyzed to norethindrone, which is metabolized via reduction and conjugation. Ferrous fumarate is absorbed and utilized for hemoglobin synthesis.
Ethinyl estradiol: CYP3A4; undergoes first-pass metabolism with sulfation and glucuronidation. Ethynodiol diacetate: Deacetylated to norethynodrel, then extensively metabolized via reduction and conjugation.
Renal (primarily as glucuronide conjugates of norethindrone and ethinyl estradiol): ~40% norethindrone metabolites, ~30% ethinyl estradiol metabolites; Fecal: ~30% norethindrone metabolites, ~40% ethinyl estradiol metabolites.
Ethinylestradiol and ethynodiol diacetate are extensively metabolized; urinary excretion accounts for ~40% of ethinylestradiol metabolites and ~50-60% of ethynodiol diacetate metabolites; fecal excretion accounts for ~30% of ethinylestradiol metabolites and ~35% of ethynodiol diacetate metabolites; biliary excretion contributes to enterohepatic circulation.
Norethindrone: ~61% bound (primarily to albumin and SHBG); Ethinyl estradiol: ~97–98% bound (primarily to albumin, with ~1–2% free).
Ethinylestradiol: >97% bound, primarily to albumin, with ~2% bound to sex hormone-binding globulin (SHBG); ethynodiol diacetate (as norethindrone): ~95% bound, primarily to albumin and SHBG.
Norethindrone: ~4 L/kg; Ethinyl estradiol: ~3–4 L/kg. Indicates extensive tissue distribution consistent with lipophilic steroids.
Ethinylestradiol: Vd ~2-4 L/kg; distributes extensively into body tissues; ethynodiol diacetate (as norethindrone): Vd ~4 L/kg; indicates wide distribution including reproductive tissues.
Norethindrone: ~64% (oral); Ethinyl estradiol: ~45% (oral) due to first-pass metabolism, with high interindividual variability.
Oral: ethinylestradiol bioavailability ~40-60% due to first-pass metabolism; ethynodiol diacetate bioavailability ~60-80% after oral administration.
No specific dosage adjustment required for renal impairment. Use with caution in patients with renal dysfunction due to potential fluid retention.
No dosage adjustment required for renal impairment. Use is not recommended in patients with severe renal impairment due to potential adverse effects.
Contraindicated in patients with hepatic impairment, including acute or chronic liver disease, hepatic adenomas, or impaired liver function. No adjustment guidelines available; do not use.
Contraindicated in patients with Child-Pugh C cirrhosis. For Child-Pugh A or B, use is generally not recommended; if used, monitor closely for adverse effects.
Not indicated for use before menarche. For post-menarchal adolescents, same dosing as adults: one tablet orally once daily.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults: one tablet orally once daily for 28 days per cycle.
Not indicated for use in postmenopausal women. No specific dosing adjustments for elderly patients as the drug is not used in this population.
Not indicated for use in postmenopausal women. No specific dose adjustment recommended for elderly, but consider increased risk of thromboembolic disorders.
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptives. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
Cigarette smoking increases risk of serious cardiovascular events (e.g., myocardial infarction, stroke, thromboembolism). Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
Increased risk of venous thromboembolism (VTE), myocardial infarction, and stroke, especially in smokers and women with hypertension or migraines,Adverse effects on bone density and potential for fractures with long-term use,Hepatic adenoma or hepatocellular carcinoma risk,Gallbladder disease,Glucose intolerance and insulin resistance,Elevated blood pressure,Cholestatic jaundice,Ocular lesions (e.g., retinal thrombosis),Depression,Iron overload in patients with hemochromatosis or chronic hemolytic anemia (due to ferrous fumarate)
Thromboembolic disorders (DVT, PE, stroke, MI),Hepatic neoplasia (benign/malignant liver tumors),Increased risk of gallbladder disease,Hypertension,Carbohydrate/lipid metabolic effects,Ocular disturbances (retinal thrombosis, optic neuritis),Depression,Fetal harm if used during pregnancy
Current or history of thrombophlebitis, DVT, or thromboembolic disorders,Cerebrovascular or coronary artery disease,Known or suspected pregnancy,Undiagnosed abnormal uterine bleeding,Breast carcinoma or other hormone-sensitive cancer,Hepatic tumor (benign or malignant) or active liver disease,Hypersensitivity to any component,Smoking in women over 35,Hemochromatosis or chronic hemolytic anemia (due to ferrous fumarate)
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease,Known or suspected breast cancer,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
No specific food interactions are known for Lo Loestrin Fe. However, grapefruit juice may increase ethinyl estradiol levels, potentially increasing side effects; it is prudent to advise against excessive grapefruit juice consumption. Iron tablets should be taken with food to reduce gastrointestinal upset; calcium-rich foods or supplements may decrease iron absorption, so separate iron intake from high-calcium meals by at least 2 hours.
No significant food interactions. Grapefruit juice may increase estrogen levels, but clinical significance is unclear. Maintain consistent intake of vitamin C-rich foods as they may increase estrogen absorption. Avoid St. John's wort, which reduces contraceptive efficacy.
Pregnancy category X. Contraindicated in pregnant women due to risk of fetal harm, including cardiovascular defects and neural tube defects. Use during first trimester associated with oral clefts; second and third trimester use may lead to fetal hyperbilirubinemia and jaundice.
Contraindicated in pregnancy. First trimester: increased risk of neural tube defects, congenital heart defects, and limb reduction defects from progestins. Second and third trimesters: association with masculinization of female fetus, adrenal suppression, and possible long-term metabolic effects. Estrogen component may increase risk of VACTERL anomalies.
Excreted in breast milk in small amounts; no reported adverse effects in infants. M/P ratio for ethinyl estradiol is approximately 0.04. Use with caution, especially during early postpartum period due to potential effects on milk production.
Contraindicated during breastfeeding. Estrogens reduce milk production and quality. M/P ratio not established; ethinyl estradiol and norgestrel are excreted in breast milk in small amounts, potentially causing adverse effects in the infant.
Not applicable; drug is contraindicated in pregnancy. No dose adjustments recommended due to absence of safe therapeutic use.
No adjustments; absolute contraindication in pregnancy. Drug should be discontinued immediately upon pregnancy diagnosis. No established safe dose in pregnancy.
Lo Loestrin Fe contains norethindrone acetate and ethinyl estradiol (1 mg/10 mcg) as the active hormonal pills, with a low iron (75 mg ferrous fumarate) supplement during the placebo week. It is the lowest-dose combination oral contraceptive available, which may minimize estrogen-related side effects. The regimen is 24 active pills, 2 placebo pills, then 2 iron pills, for a 28-day cycle. Spotting and breakthrough bleeding are common, especially in the first few cycles. It is indicated for contraception and not for emergency contraception. The iron tablets do not replace iron deficiency treatment. Contraindicated in patients with a history of thromboembolic disorders, liver disease, or known/suspected pregnancy.
Demulen 1/50-28 is a monophasic combined oral contraceptive containing ethinyl estradiol 50 mcg and ethynodiol diacetate 1 mg. Due to the 50 mcg estrogen dose, it carries an increased risk of venous thromboembolism compared to lower-dose pills; avoid in patients with migraine with aura, hypertension >160/100 mm Hg, or age >35 who smoke. The 28-day pack includes 21 active pills and 7 placebo pills; breakthrough bleeding is more common with higher estrogen. Caution with hepatic enzyme inducers like rifampin or anticonvulsants may reduce efficacy.
Take one pill daily at the same time each day, preferably after the evening meal.,The first 24 pills are light blue (hormonal), the next 2 are white (placebo), and the last 2 are brown (iron tablets).,If you miss a dose: take it as soon as remembered, and if more than 12 hours late, use backup contraception for 7 days.,Common side effects: spotting, nausea, breast tenderness, and mood changes; these often improve after 3 months.,If you experience severe abdominal or chest pain, headache, or vision changes, seek medical attention.,Iron pills do not treat anemia; they only supplement daily iron needs.,Report any jaundice, depression, or high blood pressure to your healthcare provider.,Use an additional non-hormonal method if starting for the first time after the 5th day of your period.
Take one pill daily at the same time, preferably with food to reduce nausea.,The first 7 days of the first cycle require a backup contraceptive method if not starting on day 1 of menses.,Missed pill: if one active pill is missed, take it as soon as remembered and continue; if two or more active pills are missed, take the last missed pill, skip the others, use backup for 7 days, and consider emergency contraception.,Smoking increases risk of serious cardiovascular side effects; avoid smoking, especially if over 35.,Report symptoms of blood clots: sudden leg pain/swelling, chest pain, shortness of breath, or severe headache.,The 7 placebo pills are for withdrawal bleeding; start next pack on time regardless of bleeding.
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 LOESTRIN FE vs DEMULEN 1/50-28, answered by our medical review team.
LO LOESTRIN FE is a Combination Oral Contraceptive that works by Combination of ethinyl estradiol and norethindrone acetate suppresses gonadotropin-releasing hormone (Gn RH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary, thereby inhibiting ovulation. The progestin component thickens cervical mucus, impeding sperm penetration, and alters endometrial receptivity. Ferrous fumarate provides supplemental iron.. DEMULEN 1/50-28 is a Combination Oral Contraceptive that works by Combination oral contraceptive: Ethinyl estradiol and ethynodiol diacetate suppress gonadotropin secretion (LH, FSH) via negative feedback, inhibiting ovulation. Ethynodiol diacetate also increases cervical mucus viscosity and induces endometrial changes.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between LO LOESTRIN FE and DEMULEN 1/50-28 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 LO LOESTRIN FE is: One tablet orally once daily. Each tablet contains norethindrone acetate 1 mg and ethinyl estradiol 10 mcg (24 active tablets) followed by ferrous fumarate 75 mg (2 inactive tablets).. The standard adult dose of DEMULEN 1/50-28 is: One tablet orally once daily for 28 consecutive days per cycle.. 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 LOESTRIN FE and DEMULEN 1/50-28 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. LO LOESTRIN FE is classified as Category C. Pregnancy category X. Contraindicated in pregnant women due to risk of fetal harm, including cardiovascular defects and neural tube defects. Use during first trimester associated w. DEMULEN 1/50-28 is classified as Category C. Contraindicated in pregnancy. First trimester: increased risk of neural tube defects, congenital heart defects, and limb reduction defects from progestins. Second and third trimest. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.