Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LO-BLISOVI 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 hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; norethindrone induces endometrial changes, increasing cervical mucus viscosity.
Combination estrogen-progestin contraceptive; suppresses gonadotropin release, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial receptivity.
Prevention of pregnancy,Treatment of heavy menstrual bleeding (off-label),Acne vulgaris (off-label)
Prevention of pregnancy
One tablet orally once daily for 21 consecutive days, followed by 7 days of placebo tablets.
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.
Terminal elimination half-life: 15-18 hours for ethinyl estradiol; clinical context: supports once-daily dosing
Ethinyl estradiol: 17.4 ± 5.6 h (terminal); norethindrone: 10.9 ± 1.6 h (terminal); clinically, steady-state achieved within 5-7 days.
Hepatic via CYP3A4 (ethinyl estradiol) and primarily conjugation (norethindrone); first-pass metabolism.
Ethinylestradiol undergoes hepatic metabolism via CYP3A4; norethindrone undergoes reduction and conjugation in the liver.
Renal (approximately 60% as metabolites, 10-15% as unchanged drug); fecal (about 20-30%)
Renal 50% (metabolites), fecal 50% (biliary elimination of conjugates).
Ethinyl estradiol: 95-98% bound to albumin and sex hormone-binding globulin (SHBG)
Ethinyl estradiol: 97-98% bound to albumin; norethindrone: 93% bound to albumin and SHBG.
Ethinyl estradiol: 2-5 L/kg; indicates extensive tissue distribution
Ethinyl estradiol: 2.3-4.3 L/kg; norethindrone: 4.4 L/kg; indicates extensive tissue distribution.
Oral: ethinyl estradiol approximately 40-50% (first-pass metabolism)
Ethinyl estradiol: 40-45% (oral; first-pass metabolism); norethindrone: 64-67% (oral).
No dose adjustment required in renal impairment. Use with caution if severe renal impairment or nephrotic syndrome due to potential fluid retention.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure.
Contraindicated in acute hepatic disease or severe cirrhosis (Child-Pugh class C). Not recommended in moderate impairment (Child-Pugh B) without specialist advice. No data for mild (Child-Pugh A); use caution.
Contraindicated in acute or chronic hepatic dysfunction, including Child-Pugh class A, B, or C. Avoid use if liver function tests are abnormal.
Not indicated in pediatric patients before menarche. For postmenarchal females, same adult dose may be used; weight-based dosing not established.
Not indicated for use before menarche. For postmenarchal adolescents, use same dosing as adults (one tablet orally once daily).
Not indicated in postmenopausal women. No specific geriatric dose adjustments; consider increased risk of thrombotic events and comorbidities.
Not indicated for use in postmenopausal women.
Cigarette smoking increases risk of serious cardiovascular events from COC use. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use COCs.
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.
Thrombotic disorders (DVT, PE, stroke, MI),Carcinoma (breast, cervical, liver),Hepatic disease (jaundice, cholestasis),Hypertension,Carbohydrate/lipid effects,Headache/migraine,Bleeding irregularities,Drug interactions (CYP3A4 inducers/inhibitors),Depression,Gallbladder disease,Hereditary angioedema
Increased risk of thromboembolic disorders,Cerebrovascular disease,Myocardial infarction,Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate/lipid effects,Headache,Uterine bleeding,Ocular lesions,Depression
Venous or arterial thrombotic/thromboembolic events (current or history),Cerebrovascular or coronary artery disease,Valvular heart disease with complications,Uncontrolled hypertension,Major surgery with prolonged immobilization,Diabetes with vascular involvement,Headache with focal neurological symptoms or migraine with aura (age ≥35),Current or history of breast cancer or other estrogen-sensitive neoplasia,Hepatic adenomas or malignant liver tumors,Acute or chronic liver disease with abnormal function,Undiagnosed abnormal uterine bleeding,Known or suspected pregnancy,Cigarette smoking in women >35 years,Hypersensitivity to any component
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
Grapefruit juice may increase estrogen levels and risk of adverse effects; avoid large quantities. Iron absorption is enhanced by vitamin C (e.g., orange juice) and inhibited by tannins (tea, coffee), calcium (dairy), and phytates (whole grains); separate iron intake from these foods by at least 2 hours. Take with food to reduce GI upset.
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.
Pregnancy category X. Combination hormonal contraceptives are contraindicated in pregnancy due to known risks to the fetus, including cardiovascular and limb defects from first-trimester exposure, and potential feminization of male fetuses from progestin exposure. Post-conception use is not indicated; if exposure occurs, evaluate for 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.
Small amounts of progestins and estrogens are excreted in breast milk; M/P ratio not established for this specific formulation. Use in breastfeeding women is generally not recommended due to potential effects on milk production and composition, and possible long-term effects on the infant. Alternative contraception methods are advised until weaning.
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.
Contraindicated in pregnancy. If pregnancy occurs, discontinue immediately. No dose adjustment is applicable as the drug should not be used in pregnancy. Pharmacokinetic changes in pregnancy (increased clearance) are irrelevant due to contraindication.
Contraindicated in pregnancy; no dose adjustment applicable. If inadvertently used, discontinue immediately.
LO-BLISOVI FE (norethindrone acetate/ethinyl estradiol/ferrous fumarate) is a combined oral contraceptive with iron supplementation. The iron component (75 mg ferrous fumarate) compensates for menstrual blood loss. Administer at the same time daily to maintain stable hormone levels. Missed doses increase risk of breakthrough bleeding and contraceptive failure. Consider non-oral contraceptives in patients with malabsorption or vomiting.
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 tablet daily at the same time with food to reduce nausea.,Missed doses: if one dose is missed >12 hours, take it immediately and continue; if two doses are missed, take two tablets and use backup contraception for 7 days.,Iron tablets may cause dark stools; this is harmless.,Report severe headache, chest pain, leg swelling, or vision changes immediately.,Do not smoke while taking this medication; smoking increases risk of blood clots.,Store in original blister pack; do not remove desiccant.
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 LO-BLISOVI FE vs DEMULEN 1/35-28, answered by our medical review team.
LO-BLISOVI FE is a Combination Oral Contraceptive that works by Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; norethindrone induces endometrial changes, increasing cervical mucus viscosity.. 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 LO-BLISOVI 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 LO-BLISOVI FE is: One tablet orally once daily for 21 consecutive days, followed by 7 days of placebo tablets.. 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 LO-BLISOVI 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. LO-BLISOVI FE is classified as Category C. Pregnancy category X. Combination hormonal contraceptives are contraindicated in pregnancy due to known risks to the fetus, including cardiovascular and limb defects from first-tri. 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.