Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
GILDESS FE 1.5/30 vs ALTAVERA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Combination oral contraceptive: ethinyl estradiol (estrogen) and levonorgestrel (progestin) suppress gonadotropin secretion (FSH and LH) via negative feedback, inhibiting ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.
Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.
Prevention of pregnancy
Prevention of pregnancy,Treatment of moderate acne vulgaris (in females ≥15 years with no contraindications)
One tablet orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.
Ethinyl estradiol: terminal elimination half-life approximately 13-27 hours (mean ~17 hours); clinical context: supports daily dosing with steady state achieved in ~1 week. Gestodene: terminal elimination half-life approximately 12-15 hours; clinical context: allows for maintaining stable serum concentrations with once-daily dosing.
Levonorgestrel: terminal elimination half-life 25±10 hours; ethinyl estradiol: 13±7 hours. Clinical context: steady-state concentrations achieved within 5-7 days; contraceptive efficacy requires consistent daily dosing.
Ethinyl estradiol: primarily metabolized by CYP3A4; undergoes conjugation (glucuronidation and sulfation). Levonorgestrel: metabolized by reduction and conjugation; CYP3A4 involved.
Ethinyl estradiol: primarily metabolized by CYP3A4; undergoes sulfation and glucuronidation. Desogestrel: rapidly converted to active metabolite etonogestrel via CYP2C9 and CYP2C19; further metabolism by CYP3A4.
Ethinyl estradiol (EE) is primarily excreted in urine (40-45%) and feces (40-45%) as glucuronide and sulfate conjugates; less than 8% is excreted unchanged. Gestodene is extensively metabolized; its metabolites are excreted in urine (50-60%) and feces (30-40%), with less than 1% unchanged.
Renal excretion of metabolites and unchanged drug: ~30% (levonorgestrel) and ~20% (ethinyl estradiol) in urine; biliary/fecal elimination: ~40-50% as conjugates and metabolites.
Ethinyl estradiol: 97-98% bound to albumin; gestodene: 65-75% bound to sex hormone-binding globulin (SHBG) and 25-35% bound to albumin; total binding ~99%.
Levonorgestrel: 98-99% bound to sex hormone-binding globulin (SHBG) and albumin; ethinyl estradiol: 98% bound to albumin.
Ethinyl estradiol: apparent Vd ~2.5-4.0 L/kg (mean ~3 L/kg); indicates extensive tissue distribution beyond plasma volume. Gestodene: apparent Vd ~0.7-1.0 L/kg; suggests moderate distribution to tissues.
Levonorgestrel: Vd ~1.8 L/kg (suggesting extensive tissue distribution). Ethinyl estradiol: Vd ~2.4 L/kg.
Ethinyl estradiol: oral bioavailability approximately 40-45% due to first-pass metabolism (sulfation and glucuronidation in gut wall and liver); interindividual variability significant. Gestodene: oral bioavailability nearly 100% (99-100%) due to minimal first-pass metabolism; high and consistent absorption.
Oral bioavailability: levonorgestrel ~100% (nearly complete); ethinyl estradiol ~45-50% (first-pass hepatic metabolism).
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment (e GFR <30 m L/min/1.73 m²) due to potential estrogen-related fluid retention and hypertension.
No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal disease or acute renal failure due to potential fluid retention.
Contraindicated in Child-Pugh class B and C (moderate to severe hepatic impairment). Use with caution in Child-Pugh class A; closely monitor liver function.
Contraindicated in severe hepatic dysfunction (Child-Pugh class B or C). Use caution in mild to moderate impairment (Child-Pugh A); monitor liver enzymes.
Not indicated for use before menarche. Post-menarche: same as adult dosing; one tablet orally once daily.
Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (1 tablet daily, 21/7 regimen) after evaluation of risks.
Not indicated for use in postmenopausal women due to lack of efficacy for contraception and potential increased thromboembolic risk.
Not indicated for postmenopausal women. No specific geriatric dosing; consider increased risk of thromboembolism, cardiovascular disease, and metabolic effects in older women of reproductive age.
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (especially >35 years) and number of cigarettes smoked. Women >35 years who smoke should not use this product.
Cigarette smoking increases risk of serious cardiovascular events from combined oral contraceptives. Risk increases with age (especially >35 years) and with number of cigarettes smoked. Women who use combined hormonal contraceptives should be strongly advised not to smoke.
Thrombotic disorders (venous thromboembolism, arterial thromboembolism, stroke, myocardial infarction),Carcinoma of the breast and reproductive organs,Hepatic neoplasia,Gallbladder disease,Carbohydrate and lipid metabolism effects,Elevated blood pressure,Headache,Bleeding irregularities,Ocular lesions (e.g., retinal thrombosis),Depression
Thrombotic disorders: risk of venous thromboembolism (VTE), stroke, myocardial infarction; discontinue if thrombotic event occurs.,Hepatic disease: discontinue if jaundice or liver function abnormalities develop.,Hypertension: monitor blood pressure; discontinue if uncontrolled.,Carbohydrate metabolism: may affect glucose tolerance; monitor diabetic patients.,Depression: discontinue if significant depression occurs.,Gallbladder disease: increased risk of cholelithiasis.
Thrombophlebitis or thromboembolic disorders,Cerebrovascular or coronary artery disease,Known or suspected breast cancer,Estrogen-dependent neoplasia,Undiagnosed abnormal genital bleeding,Pregnancy,Benign or malignant liver tumor,Hepatic impairment,Hypersensitivity to components,Women >35 years who smoke
Thrombophlebitis or thromboembolic disorders (current or history),Cerebrovascular or coronary artery disease (current or history),Known or suspected breast carcinoma,Estrogen-dependent neoplasia (known or suspected),Undiagnosed abnormal genital bleeding,Cholestatic jaundice of pregnancy or jaundice with prior pill use,Hepatic adenoma or carcinoma (known or suspected),Pregnancy (known or suspected),Hypersensitivity to any component
No significant food interactions. Grapefruit juice may slightly increase ethinyl estradiol levels but not clinically relevant. The iron component may cause gastrointestinal discomfort; taking with food can reduce this, but avoid taking with dairy (calcium) or caffeine as they may reduce iron absorption. Iron tablets should be taken with water or vitamin C source to enhance absorption, but not with tea, coffee, or milk.
No significant food interactions. Alcohol does not affect efficacy but may increase risk of adverse effects such as nausea. Grapefruit juice has no known interaction. Avoid excessive alcohol consumption due to potential hepatotoxicity.
Pregnancy category X. Use contraindicated in pregnancy due to estrogenic effects on fetal development. First trimester: increased risk of congenital anomalies (cardiovascular, limb defects). Second and third trimesters: potential for fetal harm, including jaundice and liver dysfunction.
ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular defects (relative risk 1.2-1.4) and no consistent increase in other major malformations. Second and third trimesters: No known teratogenic effects, but theoretical risks from estrogenic effects (e.g., feminization of male fetus). Postnatal: No increased risk of long-term developmental effects from pregnancy exposure.
Contraindicated in breastfeeding. Estrogen and progestin components reduce milk production and quality. Limited data; M/P ratio not established. Alternative contraception recommended.
Combined oral contraceptives may reduce milk production and quality, especially in early lactation. Ethinyl estradiol transfers into breast milk at low levels (M/P ratio approximately 0.1-0.2), excluding clinical effects in term infants. Levonorgestrel transfer is minimal (M/P ratio ~0.2-0.4). Use is generally avoided in breastfeeding women, especially during the first 6 weeks postpartum. Progestin-only methods are preferred.
No dose adjustment due to contraindication in pregnancy. Pharmacokinetic changes in pregnancy (increased clearance) are not applicable as drug is not used.
Contraindicated in pregnancy. No dose adjustment recommended because use is discontinued upon confirmed or suspected pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased hepatic clearance, altered binding proteins) are not relevant for this indication.
GILDESS FE 1.5/30 is a combination oral contraceptive containing ethinyl estradiol 30 mcg and gestodene 1.5 mg. Gestodene is a third-generation progestin with high progestational activity and minimal androgenic effects. The iron component (ferrous fumarate) is included to counteract menstrual blood loss. This formulation is associated with a lower risk of venous thromboembolism compared to second-generation pills but still carries a risk, particularly in smokers over 35. It should be taken at the same time daily to maintain efficacy. Breakthrough bleeding is common in the first few cycles; if persistent, rule out other causes. The iron tablets are not for contraceptive use and should be taken daily during the placebo week.
ALTAVERA is a combined oral contraceptive (COC) containing ethinylestradiol and levonorgestrel. It inhibits ovulation via suppression of gonadotropins. Counsel patients to take at the same time daily to maintain efficacy. Missed pill management: if missed within 12 hours, take immediately; if >12 hours, take last missed pill and use backup contraception for 7 days. Be aware of increased VTE risk, especially in smokers over 35. May reduce effectiveness of lamotrigine; monitor seizure control. Initiate on the first day of menses or first Sunday after onset.
Take one tablet daily at the same time, preferably after an evening meal to minimize nausea.,If you miss a dose, follow the package instructions: if missed by less than 12 hours, take it immediately; if more than 12 hours, take the last missed pill and use backup contraception for 7 days.,Use additional barrier contraception for the first 7 days of starting the pill, or if starting after day 5 of cycle, for the first cycle.,Smoking increases the risk of serious cardiovascular side effects, especially if you are over 35 years old. Do not smoke while taking this medication.,Seek immediate medical attention if you experience symptoms of a blood clot: sudden leg pain/swelling, chest pain, shortness of breath, or sudden severe headache.,The iron tablets are not for contraception; they help replace iron lost during menstruation.,Do not use this medication if you are pregnant, have a history of blood clots, certain migraines, liver disease, or hormone-sensitive cancer.,Antibiotics (except rifampin) generally do not affect efficacy, but always consult your doctor if you are prescribed any new medication.
Take one tablet daily at the same time each day, with or without food.,If you miss a pill by less than 12 hours, take it as soon as you remember. If more than 12 hours, take the missed pill and use a backup method (e.g., condoms) for the next 7 days.,Smoking increases your risk of serious cardiovascular side effects, especially if you are over 35 years old. Do not smoke while taking this medication.,Seek immediate medical attention if you experience sudden severe headache, chest pain, leg pain/swelling, or vision changes (symptoms of blood clots).,This medication does not protect against HIV or other sexually transmitted infections.,If you are taking lamotrigine or other anticonvulsants, tell your doctor; your seizure medication may be less effective.,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 GILDESS FE 1.5/30 vs ALTAVERA, answered by our medical review team.
GILDESS FE 1.5/30 is a Oral Contraceptive that works by Combination oral contraceptive: ethinyl estradiol (estrogen) and levonorgestrel (progestin) suppress gonadotropin secretion (FSH and LH) via negative feedback, inhibiting ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.. ALTAVERA is a Combined Oral Contraceptive that works by Combination of ethinyl estradiol and desogestrel: ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; desogestrel (progestin) causes cervical mucus thickening and endometrial atrophy, preventing implantation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between GILDESS FE 1.5/30 and ALTAVERA depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of GILDESS FE 1.5/30 is: One tablet orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.. The standard adult dose of ALTAVERA is: 1 tablet (ethinyl estradiol 0.03 mg / levonorgestrel 0.15 mg) orally once daily for 21 days, followed by 7 placebo days.. 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 GILDESS FE 1.5/30 and ALTAVERA 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. GILDESS FE 1.5/30 is classified as Category C. Pregnancy category X. Use contraindicated in pregnancy due to estrogenic effects on fetal development. First trimester: increased risk of congenital anomalies (cardiovascular, limb. ALTAVERA is classified as Category C. ALTAVERA contains ethinyl estradiol and levonorgestrel. First trimester: Inadvertent exposure during organogenesis is associated with a very low absolute risk of cardiovascular def. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.