GILDESS 1.5/30

Clinical safety rating: caution

Comprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).

How it works

Combination of estrogen (ethinyl estradiol) and progestin (desogestrel) that inhibits gonadotropin release, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial morphology.

What the body does with it

Metabolism	Ethinyl estradiol undergoes first-pass metabolism in gut wall and liver via CYP3A4; desogestrel is metabolized by CYP2C9 and CYP2C19 to active metabolite etonogestrel.
Excretion	Renal: ~55-60% as ethinylestradiol glucuronide and sulfate conjugates; ~40% as desogestrel metabolites (largely as 3-keto-desogestrel glucuronide). Fecal: ~30-35% of desogestrel metabolites; <5% for ethinylestradiol. Biliary: minor for both.
Half-life	Ethinylestradiol: terminal half-life 13-17 hours (mean 15 h). Desogestrel active metabolite 3-keto-desogestrel: terminal half-life 23-28 hours (mean 25 h). Clinical: steady-state achieved by cycle day 7-10; missed pill instructions based on half-life.
Protein binding	Ethinylestradiol: ~97% bound to albumin (90%) and SHBG (minor). 3-Keto-desogestrel: ~95% bound: albumin (65%) and SHBG (30%).
Volume of Distribution	Ethinylestradiol: Vd ~2.5-3.0 L/kg; distributes extensively into body tissues (breast, liver). 3-Keto-desogestrel: Vd ~1.5-2.0 L/kg; moderate tissue binding.
Bioavailability	Oral: ethinylestradiol ~40-50% (due to first-pass metabolism); desogestrel ~76% (≥60% converted to active 3-keto-desogestrel after first pass).
Onset of Action	Oral: contraceptive effect requires 7 days of continuous dosing to suppress ovulation. Maximal plasma concentrations: ethinylestradiol 1.5-2 h; 3-keto-desogestrel 1-2 h.
Duration of Action	Oral: contraceptive protection persists for the 21-day active pill period; 7-day placebo interval allows withdrawal bleed. Full ovulation suppression maintained with consistent daily dosing.

Classification & Brands

Dosing & administration

One tablet orally once daily at the same time each day.

Dosage form	TABLET
Renal impairment	Contraindicated in patients with renal impairment (eGFR <60 mL/min/1.73 m2) due to increased risk of hyperkalemia and reduced efficacy.
Liver impairment	Contraindicated in patients with hepatic impairment (Child-Pugh class B or C) due to impaired hormone metabolism and potential for adverse effects.
Pediatric use	Not indicated for use in pediatric patients. Safety and efficacy have not been established in females under 18 years of age.
Geriatric use	Not indicated for use in postmenopausal women. Efficacy in women over 40 years of age has not been fully established; consider alternative contraception due to increased cardiovascular risk.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).

Breastfeeding	Ethinyl estradiol and levonorgestrel are excreted in breast milk in small amounts. M/P ratio not established. Potential for adverse effects in nursing infant, including reduced milk production and jaundice. Use not recommended in breastfeeding women.
Teratogenic Risk	First trimester: Combination oral contraceptives are not associated with a major increase in risk of birth defects. Second and third trimesters: Prolonged use may be associated with fetal harm including cardiovascular and skeletal anomalies, though data are limited. Known pregnancy contraindicates use.

Warnings & precautions

■ FDA Black Box Warning

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).

Side Effect Profile

Serious Effects

Absolute Contraindications

["Thrombophlebitis or thromboembolic disorders","History of DVT or PE","Cerebrovascular or coronary artery disease","Known or suspected breast carcinoma","Estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Pregnancy","Hepatic adenoma or carcinoma","Active liver disease with abnormal function"]

Clinical Precautions

Precautions

["Increased risk of thromboembolic disorders (e.g., DVT, PE)","Myocardial infarction and stroke risk","Hepatic neoplasia","Gallbladder disease","Hypertension","Carbohydrate/lipid effects","Ocular lesions","Dose-related risk of VTE from desogestrel-containing pills"]

Clinical Tips & Counseling

Drug interactions

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GILDESS 1.5/30

Clinical safety rating: caution

Comprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).

How it works

What the body does with it

Metabolism	Ethinyl estradiol undergoes first-pass metabolism in gut wall and liver via CYP3A4; desogestrel is metabolized by CYP2C9 and CYP2C19 to active metabolite etonogestrel.
Excretion	Renal: ~55-60% as ethinylestradiol glucuronide and sulfate conjugates; ~40% as desogestrel metabolites (largely as 3-keto-desogestrel glucuronide). Fecal: ~30-35% of desogestrel metabolites; <5% for ethinylestradiol. Biliary: minor for both.
Half-life	Ethinylestradiol: terminal half-life 13-17 hours (mean 15 h). Desogestrel active metabolite 3-keto-desogestrel: terminal half-life 23-28 hours (mean 25 h). Clinical: steady-state achieved by cycle day 7-10; missed pill instructions based on half-life.
Protein binding	Ethinylestradiol: ~97% bound to albumin (90%) and SHBG (minor). 3-Keto-desogestrel: ~95% bound: albumin (65%) and SHBG (30%).
Volume of Distribution	Ethinylestradiol: Vd ~2.5-3.0 L/kg; distributes extensively into body tissues (breast, liver). 3-Keto-desogestrel: Vd ~1.5-2.0 L/kg; moderate tissue binding.
Bioavailability	Oral: ethinylestradiol ~40-50% (due to first-pass metabolism); desogestrel ~76% (≥60% converted to active 3-keto-desogestrel after first pass).
Onset of Action	Oral: contraceptive effect requires 7 days of continuous dosing to suppress ovulation. Maximal plasma concentrations: ethinylestradiol 1.5-2 h; 3-keto-desogestrel 1-2 h.
Duration of Action	Oral: contraceptive protection persists for the 21-day active pill period; 7-day placebo interval allows withdrawal bleed. Full ovulation suppression maintained with consistent daily dosing.

Classification & Brands

Dosing & administration

One tablet orally once daily at the same time each day.

Dosage form	TABLET
Renal impairment	Contraindicated in patients with renal impairment (eGFR <60 mL/min/1.73 m2) due to increased risk of hyperkalemia and reduced efficacy.
Liver impairment	Contraindicated in patients with hepatic impairment (Child-Pugh class B or C) due to impaired hormone metabolism and potential for adverse effects.
Pediatric use	Not indicated for use in pediatric patients. Safety and efficacy have not been established in females under 18 years of age.
Geriatric use	Not indicated for use in postmenopausal women. Efficacy in women over 40 years of age has not been fully established; consider alternative contraception due to increased cardiovascular risk.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).

Breastfeeding	Ethinyl estradiol and levonorgestrel are excreted in breast milk in small amounts. M/P ratio not established. Potential for adverse effects in nursing infant, including reduced milk production and jaundice. Use not recommended in breastfeeding women.
Teratogenic Risk	First trimester: Combination oral contraceptives are not associated with a major increase in risk of birth defects. Second and third trimesters: Prolonged use may be associated with fetal harm including cardiovascular and skeletal anomalies, though data are limited. Known pregnancy contraindicates use.

Warnings & precautions

■ FDA Black Box Warning

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).