Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
BEYAZ vs ALYACEN 1/35
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 drospirenone suppresses gonadotropins (FSH and LH) from the pituitary, inhibiting ovulation, altering cervical mucus, and inducing endometrial changes. Drospirenone is a spironolactone analogue with antimineralocorticoid and antiandrogenic activity.
Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on hypothalamic-pituitary axis; norethindrone induces progestational effects including cervical mucus thickening and endometrial changes, inhibiting ovulation and sperm penetration.
Contraception,Treatment of premenstrual dysphoric disorder (PMDD),Treatment of moderate acne vulgaris in women at least 14 years old who have achieved menarche and desire contraception
Prevention of pregnancy
One tablet (drospirenone 3 mg / ethinyl estradiol 0.02 mg) orally once daily for 24 days, followed by 4 days of placebo.
One tablet (norethindrone 1 mg and ethinyl estradiol 35 mcg) orally once daily for 21 consecutive days, followed by 7 days of placebo or no tablets.
Drospirenone: approximately 30 hours (terminal). Ethinyl estradiol: approximately 13-15 hours (terminal). Steady-state reached within 10 days. Clinical context: once-daily dosing maintains therapeutic levels with minimal accumulation after 3-4 cycles.
Norethindrone: 8-11 hours (terminal); ethinyl estradiol: 10-20 hours (terminal). The half-life supports once-daily dosing for oral contraceptive efficacy.
Primarily hepatic via CYP3A4. Ethinyl estradiol undergoes first-pass metabolism in the liver and gut wall. Drospirenone is metabolized via CYP3A4 and also undergoes reduction and sulfation. Metabolites are excreted in urine and feces.
Ethinyl estradiol: primarily hepatic via CYP3A4; norethindrone: hepatic reduction and sulfate conjugation.
Urine (45-55% as metabolites), feces (30-40% as metabolites), with enterohepatic recirculation of ethinyl estradiol metabolites.
Renal excretion of metabolites (primarily ethinyl estradiol and norethindrone conjugates) accounts for approximately 50-60% of elimination; fecal excretion accounts for 30-40%. Unchanged drug excretion is minimal (<5%).
Drospirenone: 95-97% bound (primarily to albumin). Ethinyl estradiol: approximately 98% bound (mostly to albumin).
Norethindrone: 61% bound to albumin and SHBG; ethinyl estradiol: 97-98% bound to albumin.
Drospirenone: approximately 3.7 L/kg (suggests moderate tissue distribution). Ethinyl estradiol: approximately 3.6 L/kg (consistent with distribution into body water). Clinical meaning: not extensively stored in tissues.
Norethindrone: 3.8-4.5 L/kg; ethinyl estradiol: 2.0-4.0 L/kg. Large Vd indicates extensive tissue distribution.
Oral: Drospirenone ~76% (relative to IV). Ethinyl estradiol ~55% (due to first-pass metabolism).
Oral: Norethindrone ~64%, ethinyl estradiol ~38-48% (due to first-pass metabolism).
Contraindicated in patients with renal impairment (creatinine clearance < 50 m L/min). No dose adjustment is recommended for mild impairment (Cr Cl >= 50 m L/min); however, careful monitoring is advised.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment or acute renal failure due to potential fluid retention and electrolyte disturbances.
Contraindicated in patients with hepatic impairment (Child-Pugh class A, B, or C). Do not use in acute or chronic liver disease.
Contraindicated in patients with hepatic impairment, including Child-Pugh class B or C, due to impaired metabolism of estrogen and progestin. Not recommended in patients with active liver disease or history of liver tumors.
Not indicated for use before menarche. For postmenarchal adolescents, dose is same as adults: one tablet daily following the 24/4 regimen.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults. Safety and efficacy established for contraception; weight-based dosing not applicable.
Not indicated for use in postmenopausal women. No specific geriatric dosing is established; use not recommended in this population.
Not indicated for use after menopause due to lack of benefit and increased risks (e.g., cardiovascular, thromboembolic events). If used, monitor for fluid retention, hypertension, and glucose intolerance.
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptives (COCs). This risk increases with age, especially in women over 35 years, and with the number of cigarettes smoked. Women who use COCs should be strongly advised not to smoke.
Cigarette smoking increases risk of serious cardiovascular events from combined oral contraceptives. Risk increases with age and heavy smoking (≥15 cigarettes/day). Women over 35 who smoke should not use this product.
Thrombotic disorders: venous thromboembolism, arterial thromboembolism, stroke, myocardial infarction,Hepatic disease: jaundice, cholestasis, hepatic adenomas,Hypertension: monitor blood pressure,Hyperkalemia: risk in patients with renal impairment, hepatic impairment, or adrenal insufficiency; avoid use with potassium-sparing diuretics or potassium supplements,Gallbladder disease,Carbohydrate and lipid metabolic effects,Headache/migraine,Bleeding irregularities,Depression,Carcinoma: breast and cervical,Ocular lesions: retinal thrombosis
Thrombotic disorders (e.g., DVT, PE, stroke, MI),Cerebrovascular disease,Hepatic neoplasia,Gallbladder disease,Hypertension,Carbohydrate and lipid effects,Ocular lesions,Hereditary angioedema,Chloasma,Menstrual irregularities,Pregnancy exclusion prior to initiation
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast cancer,Carcinoma of the endometrium or other known or suspected estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenomas or carcinomas (current or history),Known or suspected pregnancy,Hypersensitivity to any component of the product,Renal impairment,Adrenal insufficiency,Hyperkalemia,Use with potassium-sparing diuretics, potassium supplements, or other drugs that increase potassium
Venous or arterial thrombotic/thromboembolic disease (current or history),Cerebrovascular disease,Coronary artery disease,Known or suspected breast cancer,Endometrial 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,Smoking in women over 35
Grapefruit and grapefruit juice should be avoided as they inhibit CYP3A4, potentially increasing ethinyl estradiol levels and risk of adverse effects. No other specific food interactions are documented, but consider that high potassium foods (e.g., bananas, oranges, spinach) may theoretically contribute to hyperkalemia in susceptible patients, though routine avoidance is not required. Alcohol may increase the risk of liver toxicity, but moderate use is not contraindicated.
No significant food interactions. Grapefruit juice may increase estrogen levels, but clinically not a concern. Avoid excessive alcohol, which may impair liver function and increase estrogen exposure. Maintain a healthy diet, as weight gain is possible.
Pregnancy category X. Contraindicated in pregnancy due to known teratogenic effects, including cardiovascular and skeletal anomalies, particularly during first trimester. Use during second and third trimesters is associated with feminization of male fetuses and potential hepatic adenoma. Discontinue immediately if pregnancy occurs.
Pregnancy category X. Use of ALYACEN 1/35 (norethindrone/ethinyl estradiol) is contraindicated during pregnancy. First trimester: Increased risk of congenital anomalies, including cardiovascular defects and limb reduction defects. Second/third trimesters: Potential for urogenital abnormalities and feminization of male fetus. Exposure is associated with subsequent development of clear cell adenocarcinoma of vagina/cervix in female offspring (DES-related).
Excreted in human breast milk. M/P ratio not determined. Can reduce milk production and composition. Use is generally contraindicated during breastfeeding due to potential adverse effects in the infant, including jaundice and fluid retention.
Small amounts of contraceptive steroids and/or metabolites have been identified in breast milk. M/P ratio: Not specifically determined for this combination; ethinyl estradiol M/P ratio ~0.02-0.04. Use may reduce milk production and quality. Breastfeeding not recommended during use. Alternative contraception advised.
Not applicable: contraindicated during pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased clearance) are irrelevant as drug should be discontinued.
Contraindicated in pregnancy; no dose adjustments applicable. Discontinue medication immediately upon pregnancy detection.
BEYAZ (drospirenone/ethinyl estradiol) is a combined oral contraceptive (COC) with a 24/4 regimen. The drospirenone component has antimineralocorticoid activity, which can be beneficial for patients with fluid retention or acne. Monitor potassium levels in patients on concomitant medications that increase potassium (e.g., ACE inhibitors, ARBs, NSAIDs). BEYAZ is contraindicated in patients with renal impairment (Cr Cl <30 m L/min) due to risk of hyperkalemia. The 24 active pill regimen provides a longer window of ovulation suppression and may reduce breakthrough bleeding compared to 21-day regimens. Use with caution in patients with a history of depression; drospirenone may affect mood.
ALYACEN 1/35 is a combination oral contraceptive containing ethinyl estradiol 35 mcg and norgestimate 1 mg. It is indicated for the prevention of pregnancy and for the treatment of moderate acne vulgaris in females ≥15 years of age who desire an oral contraceptive. Monitor for thromboembolic events, especially in smokers over 35 or those with migraine with aura. Use with caution in patients with liver impairment or history of cholestatic jaundice. The pill-free interval should not exceed 7 days; missed pills increase ovulation risk. Consider non-hormonal backup if vomiting or diarrhea occurs within 4 hours of dosing.
Take one pill at the same time each day, preferably in the evening to minimize nausea.,If you miss a pill, follow the package insert instructions: for one missed pill, take it as soon as remembered; for two or more missed pills, use backup contraception (e.g., condoms) for at least 7 days.,Avoid eating grapefruit or drinking grapefruit juice while taking this medication because it can increase estrogen levels and risk of side effects.,Do not smoke while using BEYAZ, especially if you are over 35, as smoking increases the risk of serious cardiovascular events.,Side effects may include nausea, breast tenderness, headache, and mood changes; report persistent symptoms to your provider.,Seek immediate medical attention if you experience signs of a blood clot: sudden leg swelling, chest pain, shortness of breath, or sudden severe headache.,BEYAZ does not protect against HIV or other sexually transmitted infections; use condoms for protection.
Take one tablet daily at the same time each day; do not skip doses.,Use an additional non-hormonal contraceptive (e.g., condoms) if you miss a pill, have vomiting, or diarrhea.,Smoking while on this pill increases the risk of blood clots and stroke, especially if you are over 35.,Contact your healthcare provider immediately if you have chest pain, leg pain/swelling, sudden vision changes, or severe headache.,This medication does not protect against HIV or other sexually transmitted infections.,Store at room temperature, away from moisture and heat.
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 BEYAZ vs ALYACEN 1/35, answered by our medical review team.
BEYAZ is a Oral Contraceptive that works by Combination of ethinyl estradiol and drospirenone suppresses gonadotropins (FSH and LH) from the pituitary, inhibiting ovulation, altering cervical mucus, and inducing endometrial changes. Drospirenone is a spironolactone analogue with antimineralocorticoid and antiandrogenic activity.. ALYACEN 1/35 is a Oral Contraceptive that works by Combination hormonal contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on hypothalamic-pituitary axis; norethindrone induces progestational effects including cervical mucus thickening and endometrial changes, inhibiting ovulation and sperm penetration.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between BEYAZ and ALYACEN 1/35 depend on the specific clinical indication. These are both 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 BEYAZ is: One tablet (drospirenone 3 mg / ethinyl estradiol 0.02 mg) orally once daily for 24 days, followed by 4 days of placebo.. The standard adult dose of ALYACEN 1/35 is: One tablet (norethindrone 1 mg and ethinyl estradiol 35 mcg) orally once daily for 21 consecutive 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 BEYAZ and ALYACEN 1/35 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. BEYAZ is classified as Category C. Pregnancy category X. Contraindicated in pregnancy due to known teratogenic effects, including cardiovascular and skeletal anomalies, particularly during first trimester. Use durin. ALYACEN 1/35 is classified as Category C. Pregnancy category X. Use of ALYACEN 1/35 (norethindrone/ethinyl estradiol) is contraindicated during pregnancy. First trimester: Increased risk of congenital anomalies, including . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.