GLP-1 and Fertility: What Men and Women Need to Know Before Trying to Conceive

May 24, 2026

GLP-1 and Fertility: What Men and Women Need to Know Before Trying to Conceive

By Dr. Onikepe Adegbola, MD PhD — Johns Hopkins-trained physician-scientist and founder of Casa de Sante

Key Takeaways

GLP-1 medications must be stopped before pregnancy. Semaglutide: stop 2 months before trying to conceive. Tirzepatide: stop 1 month before. These timelines are based on the drug's elimination half-life.
The "Ozempic baby" phenomenon is real: weight loss from GLP-1 can restore ovulation in women with obesity-related anovulation (especially PCOS patients). Unexpected pregnancies have occurred in women who believed they were infertile.
In women with PCOS, weight loss of 5-10% can restore ovulatory cycles. GLP-1 often achieves 10-20% loss, making previously anovulatory women suddenly fertile — sometimes before they've stopped their medication.
For men: obesity reduces testosterone and impairs sperm quality. Weight loss via GLP-1 can improve testosterone, sperm count, and sperm motility.

Women: How GLP-1 Affects Fertility

The PCOS Connection

PCOS affects 10-15% of reproductive-age women. It's the leading cause of anovulatory infertility.
Excess body fat → insulin resistance → hyperinsulinemia → excess androgen production → follicular arrest → anovulation.
GLP-1 breaks this chain: weight loss + direct insulin-sensitizing effects → lower insulin → lower androgens → follicles mature → ovulation resumes.
Studies show tirzepatide (Mounjaro/Zepbound) achieves menstrual regularity in PCOS patients at rates comparable to dedicated fertility treatments.

The Oral Contraceptive Warning

GLP-1 medications slow gastric emptying, which can delay absorption of oral contraceptive pills.
Delayed absorption = potentially reduced contraceptive efficacy.
Women on GLP-1 who rely on oral contraceptives should use backup barrier methods — especially during dose titration when gastric emptying effects are most variable.
Long-acting contraceptives (IUD, implant, injection) are not affected by GLP-1.

Stopping GLP-1 Before Conception

Semaglutide (Ozempic/Wegovy): Half-life ~7 days. FDA recommends stopping at least 2 months before planned conception.
Tirzepatide (Mounjaro/Zepbound): Half-life ~5 days. Recommended to stop at least 1 month before.
Liraglutide (Saxenda): Half-life ~13 hours. Stop at least 1 month before.
Animal studies showed some reproductive toxicity at high doses. No human fertility data is available (pregnant patients are excluded from trials). The precaution is based on the precautionary principle.

Men: How Weight Loss Improves Reproductive Health

Testosterone: Visceral fat converts testosterone to estrogen (via aromatase enzyme). More fat = lower testosterone. Weight loss of 10-15% can increase testosterone by 50-100 ng/dL.
Sperm quality: Obesity is associated with reduced sperm count, motility, and morphology. Heat from excess scrotal fat also impairs spermatogenesis.
Erectile function: Obesity → endothelial dysfunction → reduced blood flow → ED. Weight loss often improves erectile function independent of other treatments.

Nutritional Planning for Pre-Conception

Folate: Begin 400-800mcg methylfolate at least 3 months before conception (both partners — folate affects sperm quality too).
Vitamin D: Optimize to 40-60 ng/mL. Vitamin D receptors are present in ovarian and testicular tissue. Deficiency is associated with reduced fertility.
Iron: Women need adequate iron stores before pregnancy. Test ferritin and supplement if below 30 ng/mL.
Omega-3 (DHA): Critical for fetal brain development. Begin supplementation before conception.
Limit caffeine: Evidence suggests limiting to 200mg/day (one 12-oz coffee) during preconception and pregnancy.
Stop alcohol: Both partners. Alcohol impairs oocyte quality, sperm quality, and early embryo development.

🛒 Pre-Conception Nutrition

Daily Vitamin — Contains folate, iron, vitamin D, zinc, and B12 — all critical pre-conception nutrients. After months on GLP-1 with reduced food intake, nutritional stores may be depleted. Replenishing these before conception gives the best start to pregnancy. Start at least 3 months before trying to conceive.
Whey Protein — Protein adequacy supports hormonal balance, ovulation, and oocyte quality. After stopping GLP-1, appetite returns — but the habit of low protein intake may persist. Protein supplementation ensures adequate intake during the critical pre-conception period.
Collagen Peptides — Glycine is conditionally essential during pregnancy (demand exceeds the body's synthesis capacity). Building glycine stores before conception supports the massive collagen needs of pregnancy (placenta, fetal tissue, maternal tissue expansion).

Medical Disclaimer: This article is for educational purposes only. GLP-1 medications are NOT approved for use during pregnancy. If you become pregnant while on GLP-1, stop the medication immediately and contact your OB-GYN. Fertility planning should involve your prescribing physician, OB-GYN, and potentially a reproductive endocrinologist. Dr. Adegbola is the founder of Casa de Sante.

Back to blog

Keto. Paleo. No Digestive Triggers. Shop Now

No onion, no garlic – no pain. No gluten, no lactose – no bloat. Low FODMAP certified.

Stop worrying about what you can't eat and start enjoying what you can. No bloat, no pain, no problem.

Our gut friendly keto, paleo and low FODMAP certified products are gluten-free, lactose-free, soy free, no additives, preservatives or fillers and all natural for clean nutrition. Try them today and feel the difference!

Country/region

GLP-1 and Fertility: What Men and Women Need to Know Before Trying to Conceive

Key Takeaways

Women: How GLP-1 Affects Fertility

The PCOS Connection

The Oral Contraceptive Warning

Stopping GLP-1 Before Conception

Men: How Weight Loss Improves Reproductive Health

Nutritional Planning for Pre-Conception

🛒 Pre-Conception Nutrition

Keto Paleo Low FODMAP, Gut & Ozempic Friendly