GLP-1 agonists can slow absorption of oral medications, including birth control pills, potentially reducing their effectiveness—especially during dose escalation when GI effects are strongest. Additionally, weight loss itself can increase fertility in people with obesity-related anovulation. Multiple unplanned pregnancies have been reported in people starting GLP-1 therapy. If you rely on oral contraceptives, consider adding a backup method (condoms, IUD) during the first few months, or switch to a non-oral contraceptive method.