The Food and Drug Administration approved a new once-weekly contraceptive patch on July 29, offering a low-estrogen option for women with a body mass index below 30.
Patch delivers steady hormone dose over seven days
Gwyn Lo, developed by Viatris, combines norelgestromin and ethinyl estradiol in a thin adhesive patch. It releases 220 micrograms of norelgestromin and 20 micrograms of ethinyl estradiol daily. Users replace the patch every seven days for three weeks, then take a patch-free week.
The FDA approved the product under the 505(b)(2) regulatory pathway, which lets manufacturers use existing safety data from similar products. The approval was supported by results from the phase 3 Luminous Study, which followed about 1,200 women over 13 cycles.
Effectiveness and side effects measured in year-long trial
The Pearl Index, the primary measure of efficacy, showed 4.14 pregnancies per 100 woman-years of use. While this rate aligns with other combined hormonal contraceptives, direct comparisons between studies remain challenging.
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Adhesion proved reliable in real-world conditions. Only 1.3% of nearly 40,000 patches applied during the trial fully detached. Additional studies confirmed consistent drug delivery during sauna sessions, treadmill exercise, and cold-water baths.
Unscheduled bleeding or spotting decreased over time. In the first cycle, 34.5% of participants experienced it, lasting an average of 3.2 days. By cycle 13, those rates fell to 20.0% and 2.4 days.
Common side effects included application site irritation (4.8%), intercycle bleeding (3.9%), and skin redness or itching (3.7%). Nausea and heavy withdrawal bleeding each affected 2.0% of users.
Who can use the patch—and who can’t
The product is approved for women of childbearing potential with a BMI under 30 who are suitable for combined hormonal contraception. The label excludes women over 35 who smoke due to increased cardiovascular risks. It also bars those with a BMI of 30 or higher, citing a higher risk of venous thromboembolism in that group.
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For women with a BMI between 25 and 30, the patch remained effective. The label does not impose further restrictions for this subgroup.
Viatris plans to launch the patch in pharmacies later this year but has not released pricing or insurance coverage details.
In 2019, unintended pregnancy accounted for 41.6% of pregnancies in the United States. A 2023 CDC survey found that 18.1% of women who had used a contraceptive method changed or stopped it within the previous 12 months, and of those, 42.8% reported not liking the method they had been using. A discreet, once-weekly option could reduce these frustrations.
