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

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

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

Why "Ozempic Babies" Are Happening

Women who were previously infertile are getting pregnant — sometimes unexpectedly — after starting GLP-1 medications. The mechanism is straightforward:

Obesity and Infertility

• Excess body fat converts androgens to estrogens (aromatization), disrupting the hormonal feedback loop
• Obesity causes insulin resistance, which increases testosterone production in women
• PCOS (polycystic ovarian syndrome) — present in up to 70% of obese women trying to conceive — prevents regular ovulation
• Excess weight is associated with thicker endometrial lining, altered uterine receptivity, and higher miscarriage rates

How Weight Loss Restores Fertility

• Even 5-10% body weight loss can restore ovulation in anovulatory women
• Insulin sensitivity improves, reducing testosterone production
• Menstrual cycles become regular
• Women who were told they could not conceive begin ovulating — sometimes before they realize it

This is why "Ozempic baby" pregnancies often happen in the first 3-6 months of treatment — the period of most rapid weight loss and hormonal change.

Stopping GLP-1 Before Conception

Current FDA guidance: stop semaglutide at least 2 months before planned conception. Stop tirzepatide at least 1 month before.

Why: Animal studies showed potential adverse effects on fetal development at high doses. There is limited human data. The washout period ensures the drug is cleared from the body before conception. GLP-1 medications have long half-lives (semaglutide: ~1 week), so the 2-month recommendation provides ~8 half-lives of clearance.

Oral Contraceptive Interaction

This is an underappreciated risk. GLP-1 medications slow gastric emptying, which can delay and reduce the absorption of oral medications — including birth control pills. The clinical significance is debated, but:

• Novo Nordisk and Eli Lilly both note this potential interaction in prescribing information
• Women on oral contraceptives should use backup contraception (barrier methods) during the first 4-6 weeks of GLP-1 treatment and during dose increases
• Non-oral contraceptives (IUD, implant, injection) are not affected by gastric emptying changes

Male Fertility and GLP-1

Less discussed but equally important:

• Testosterone increases: Obesity reduces testosterone through aromatization (fat converts testosterone to estrogen). Weight loss reverses this.
• Sperm quality improves: Obesity is associated with lower sperm count, reduced motility, and increased DNA fragmentation. Weight loss from GLP-1 medications improves all parameters.
• Erectile function improves: Through improved blood flow, reduced inflammation, and increased testosterone.

Nutrition During Fertility and GLP-1 Use

Whether you are trying to conceive or just came off GLP-1 medication, nutritional support is critical:

• Protein intake: 80-100g daily minimum. Protein supports hormonal balance, egg/sperm quality, and prevents muscle loss. Casa de Sante Whey Protein provides 25g per shake — 2 shakes covers half your daily protein need.
• Prenatal vitamins: Start 3 months before trying to conceive. Folic acid is essential for preventing neural tube defects.
• Gut health: A healthy microbiome supports hormone metabolism, nutrient absorption, and immune function — all critical for fertility. Casa de Sante FODMAP Enzymes + Probiotics supports microbiome health.
• Digestive enzyme support: Digestive enzymes ensure you are absorbing nutrients from the food you eat — critical when you are eating less on GLP-1.

Frequently Asked Questions

I got pregnant while on Ozempic. Should I be worried?

Do not panic. While the FDA recommends stopping before conception, many women have inadvertently conceived while on semaglutide. Current evidence does not show clear evidence of harm in humans, but long-term data is limited. Stop the medication immediately and notify your OB/GYN. They will monitor your pregnancy closely. The vast majority of reported "Ozempic babies" are healthy.

Will I gain weight back after stopping GLP-1 for pregnancy?

Some weight regain is possible, and some weight gain is expected during pregnancy. Maintain the healthy eating habits established while on medication. Adequate protein, regular exercise, and continued supplement support help maintain metabolic gains.