Evidence-graded answer
Does GLP-1 affect fertility?
In adults with PCOS or obesity-related infertility, GLP-1-mediated weight loss often improves ovulation and fertility. There is anecdotal "Ozempic baby" reports of unplanned pregnancies after years of infertility. GLP-1 is not recommended during pregnancy and should be stopped at least 2 months before conception attempts.
Weight loss of 5-10% reliably improves ovulatory function in PCOS. GLP-1 is one of the most effective pharmacologic paths to that threshold.
Tirzepatide reduces oral contraceptive effectiveness in the first 4 weeks of each dose escalation (see related Q: "Does GLP-1 affect birth control"). Combined with improved fertility, this is the mechanism behind several reported unplanned pregnancies.
Plan ahead: stop GLP-1 at least 2 months before conception attempts (both prescribing labels recommend this).