Evidence explainerFertility & Prenatal

Trying to Conceive? Medicines and Supplements to Stop or Review First

A few things need to stop well before you try: semaglutide at least 2 months ahead, isotretinoin at least 1 month ahead, and high-dose vitamin A. The CDC says alcohol has no known safe amount; ACOG says under 200 mg of caffeine a day is not a major miscarriage risk factor.

By Kymata Health editorial teamPublished October 10, 2026Last verified October 10, 2026

Medical review pending. Written by our editorial team from the studies and documents cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • Wegovy's label says to stop semaglutide at least 2 months before a planned pregnancy because of its long half-life [1].
  • Zepbound's label says to stop tirzepatide when a pregnancy is recognized, and that it can make birth-control pills less reliable [2].
  • Experts advise women who are or might be pregnant not to take more than 3,000 mcg RAE (10,000 IU) of preformed vitamin A a day from supplements [3]; beta-carotene is not known to cause birth defects [3].
  • Isotretinoin users must avoid pregnancy for 1 month before, during and 1 month after treatment [5].
  • The CDC says there is no known safe amount of alcohol when trying to get pregnant [6]; ACOG says under 200 mg of caffeine a day does not appear to be a major factor in miscarriage or preterm birth [7].

GLP-1 weight-loss drugs

Because of the potential for fetal harm, Wegovy's label says to stop semaglutide at least 2 months before you plan to become pregnant, to allow for its long half-life [1]. Zepbound's label says weight loss offers no benefit in pregnancy and may cause fetal harm, and to stop tirzepatide when a pregnancy is recognized [2].

Tirzepatide also slows stomach emptying enough to make birth-control pills less reliable, so its label advises a non-oral method or a backup barrier method for 4 weeks after starting and after each dose increase [2]. Our GLP-1 and pregnancy guide has the details.

Vitamin A and retinoids

In a study of 22,748 pregnant women, those taking more than 10,000 IU of preformed vitamin A a day from supplements had 4.8 times the rate of certain birth defects of those taking 5,000 IU or less, with the excess concentrated in exposure before the seventh week [4]. Experts now advise women who are or might be pregnant not to take more than 3,000 mcg RAE (10,000 IU) a day of vitamin A supplements [3].

Check supplement labels for the form and amount of vitamin A; beta-carotene is not known to be teratogenic [3]. The acne drug isotretinoin requires avoiding pregnancy for 1 month before, during and 1 month after treatment, under the iPLEDGE program [5]. See our vitamin A monograph.

Alcohol and caffeine

The CDC says there is no known safe amount of alcohol use during pregnancy or when you are trying to get pregnant, and that alcohol can cause problems before a woman knows she is pregnant [6].

For caffeine, ACOG's committee opinion concludes that moderate intake, under 200 mg a day, does not appear to be a major contributing factor in miscarriage or preterm birth [7].

Review everything else with your clinician

The FDA advises talking to a doctor or pharmacist before using any dietary supplement, partly because some interact with medicines [8]. Supplements, including fertility blends, are not FDA-approved before they are sold [8]. Bring a list of:

  • Every prescription medicine you take.
  • Herbal products and fertility or hormone-balancing blends, which the FDA does not approve before sale [8].
  • High-dose single nutrients, especially vitamin A [3].
  • Your prenatal vitamin, to confirm it has 400 to 800 mcg of folic acid; see our prenatal vitamin guide.

Partners we link to

Paid links: we earn a commission if you buy through these, at no extra cost to you. It never changes what the evidence sections say. Affiliate disclosure.

  • Natural CyclesPaid linkAn app the FDA authorized in 2018 for women 18 and older to monitor their fertility, for preventing a pregnancy or planning one; it reads your temperature data to flag fertile days. It does not protect against STIs.See Natural Cycles

Quick answers

How long before trying to conceive should I stop semaglutide?

At least 2 months, according to Wegovy's prescribing information [1].

Is my multivitamin's vitamin A a problem?

Check the form and dose: experts advise against more than 3,000 mcg RAE (10,000 IU) a day of preformed vitamin A from supplements, while beta-carotene is not known to cause birth defects [3].

More in Fertility & Prenatal

References

  1. [1]WEGOVY (semaglutide) injection and tablets: prescribing information. U.S. Food and Drug Administration (Drugs@FDA), 2026.
  2. [2]ZEPBOUND (tirzepatide) injection: prescribing information. U.S. Food and Drug Administration (Drugs@FDA), 2026.
  3. [3]Vitamin A and Carotenoids: Fact Sheet for Health Professionals (accessed October 2026). NIH Office of Dietary Supplements, 2026.
  4. [4]Teratogenicity of high vitamin A intake. N Engl J Med, 1995. PMID 7477116
  5. [5]Isotretinoin (MedlinePlus drug information, accessed October 2026). U.S. National Library of Medicine, 2026.
  6. [6]About Alcohol Use During Pregnancy (reviewed August 14, 2026). Centers for Disease Control and Prevention, 2026.
  7. [7]Moderate Caffeine Consumption During Pregnancy (Committee Opinion No. 462, reaffirmed 2026). American College of Obstetricians and Gynecologists, 2010.
  8. [8]Questions and Answers on Dietary Supplements. U.S. Food and Drug Administration, 2026.

Dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Prescription options need a licensed clinician. Talk to your clinician or pharmacist before starting anything new, especially if you take prescription medicines, are pregnant or breastfeeding.

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