FDA Approval

FDA Approves Gwyn Lo Once-Weekly Contraceptive Patch for Pregnancy Prevention

Anthony Calabro, MA

Key Highlights

  • The norelgestromin and ethinyl estradiol transdermal patch is approved to prevent pregnancy in women with a BMI below 30 kg/m² who are appropriate candidates for combined hormonal contraception.
  • Approval was granted through the FDA’s 505(b)(2) pathway and supported by the phase 3 Luminous Study.
  • The Pearl Index was 4.14 pregnancies per 100 woman-years of exposure among efficacy-evaluable participants aged 18 to 35 years.
  • Common adverse reactions included application-site irritation, erythema, and pruritus, as well as intercycle bleeding, heavy withdrawal bleeding, and nausea.

On July 29, 2026, the FDA approved norelgestromin and ethinyl estradiol transdermal system (Gwyn Lo, Viatris Inc.) for the prevention of pregnancy in women with a BMI below 30 kg/m² for whom a combined hormonal contraceptive is appropriate.

The contraceptive patch is applied once weekly for 3 consecutive weeks, followed by 1 patch-free week. Each patch provides controlled transdermal delivery of norelgestromin and ethinyl estradiol throughout the 7-day wear interval.¹ The once-weekly, low-dose estrogen contraceptive patch delivers norelgestromin 220 mcg/day and ethinyl estradiol 20 mcg/day. Approval was granted under the FDA’s 505(b)(2) regulatory pathway.¹

The approval was supported by the phase 3 Luminous Study (NCT05139121), which evaluated contraceptive efficacy, safety, cycle control, and patch adhesion during a year-long trial. The primary efficacy endpoint was the Pearl Index, defined as the number of pregnancies per 100 woman-years of exposure in the efficacy-evaluable population of women aged 18 to 35 years. The Pearl Index was 4.14 (95% CI, 2.77-5.95).

Among 39,790 transdermal systems applied during the study, 1.3% fully detached. Rates of unscheduled bleeding or spotting decreased from 34.5% in cycle 1 to 20% by cycle 13, while the mean duration declined from 3.2 to 2.4 days. Four phase 1 studies also reported consistent drug delivery across application sites and under conditions including sauna use, whirlpool exposure, treadmill exercise, and a cold-water bath.¹

The most common adverse reactions occurring in at least 2% of participants were application-site irritation (4.8%), intercycle bleeding (3.9%), application-site erythema (3.7%), application-site pruritus (3.7%), heavy withdrawal bleeding (2%), and nausea (2%).

The norelgestromin and ethinyl estradiol transdermal patch is contraindicated in women who smoke and are older than 35 years because of an increased risk of serious cardiovascular events. The patch is also contraindicated in women with a BMI of 30 kg/m² or higher. Additionally, the risk of venous thromboembolism may be greater in women with a BMI above 30 kg/m² than in women with a lower BMI.¹

Reference

  1. Viatris Inc. Viatris receives US FDA approval for Gwyn Lo, a once-weekly contraceptive patch. Published July 29, 2026. Accessed August 5, 2026. https://newsroom.viatris.com/2026-07-29-Viatris-Receives-U-S-FDA-Approval-for-Gwyn-Lo-TM-,-a-Once-Weekly-Contraceptive-Patch