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Is biotin safe during pregnancy?

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated .

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

NIH sets the adequate intake of biotin in pregnancy at 30 mcg a day, the same as for other adults, and has set no upper limit. It reports that at least a third of pregnant women develop marginally low biotin status. No source checked tested high-dose biotin supplements in pregnant women.1,2

Key facts

  • The adequate intake of biotin is 30 mcg a day in pregnancy, the same as for other adults.1,2
  • NIH says at least a third of pregnant women develop marginal biotin deficiency despite normal intakes, and that more research is needed on what this means.1
  • The main supplement trial the sources describe gave 300 mcg of biotin a day for 14 days to 26 pregnant women. It tracked a urine marker, not pregnancy outcomes.3
  • No upper limit is set for biotin, but amounts above the recommended intake can make some blood tests read falsely high or low.1,4
  • Biotin sits in many products: NIH names multivitamins, B-complex supplements and biotin-only supplements.2

What NIH says about biotin in pregnancy

NIH's fact sheet for consumers lists pregnant women among the groups more likely to have trouble getting enough biotin. Its fact sheet for health professionals explains why that group is named, and the two entries below are quoted from the biotin file on this site.1,2

Adults need 30 mcg of biotin a day, the same amount during pregnancy, and 35 mcg while breastfeeding. These are adequate intakes, set because there was not enough evidence for a recommended dietary allowance.1,2

At least a third of pregnant women develop marginally low biotin status despite normal intakes, and biotin in blood and breast milk falls during breastfeeding even when intake is above the adequate intake. What this means for health is not yet known.1

The sources describe low biotin status in pregnancy, not harm from extra biotin. They do not say that a supplement above 30 mcg changes anything for the pregnancy, in either direction.1

Has high-dose biotin been studied in pregnancy?

The sources checked describe one randomized, placebo-controlled trial of biotin in pregnant women. It enrolled 26 women whose urine showed a marker linked to low biotin status, 10 in early pregnancy (6 to 17 weeks) and 16 in late pregnancy, and gave 300 mcg a day for 14 days. The marker fell on biotin and rose on placebo. The authors raised concern about possible human birth defects from marginal deficiency, which is a concern about too little biotin, not too much.3

A later review by the same researcher repeats that marginal deficiency may be common in normal pregnancy and may carry a risk of birth defects. It also covers the lab test errors that large biotin intakes cause.5

What is not known: none of these sources tested the large amounts sold in hair, skin and nail products in pregnant women. NIH's statement that no toxicity has been shown in humans cites studies of 10 to 50 mg a day, and it does not describe those studies as including pregnant women, so it cannot be carried over to pregnancy with certainty.1,2

Does biotin affect blood tests during pregnancy care?

The documented problem with extra biotin is wrong lab results. Many tests use biotin as part of how they work, so extra biotin in a blood sample can push a result up or down.1,4

Biotin above the recommended intake can make some lab tests read falsely high or falsely low, depending on how the test is built. Wrong results can lead to the wrong treatment or to a missed or mistaken diagnosis.1,4

A laboratory review lists estradiol, progesterone, testosterone, LH and FSH among the hormone tests biotin can affect, and describes beta hCG tests, the ones used to confirm pregnancy, as robust.6

Urine is a different sample. In a 2023 trial in 10 men, 20 mg a day of biotin lowered urine hCG readings on lab tests built on biotin-streptavidin binding. The trial did not include pregnant women or home pregnancy tests, so what it means for them is not known.7

FDA advises health care providers to ask patients about biotin when a result does not fit the clinical picture. People who take biotin and have blood work or a pregnancy-related test ahead are among those who should ask their doctor whether it could affect the result.1,4

Who should ask a doctor about biotin in pregnancy

  • People who take a biotin product above what their prenatal vitamin already contains, so they should ask their doctor how much biotin is reasonable for them.2
  • People with a blood test or scan coming up who take biotin or a B-complex product, who should ask their doctor whether to pause it first.1,4
  • People who also take levothyroxine or another thyroid medicine, because biotin can distort the thyroid tests used to adjust the dose.1,8
  • People using a product that combines biotin with other ingredients, such as a hair, skin and nail blend, who should ask a pharmacist to read the full panel.

The Supplement Facts panel of each product shows its biotin. NIH says biotin appears in multivitamin and mineral supplements and in B-complex supplements as well as in biotin-only products, so the total can add up.2

Questions people ask

Is biotin shampoo safe during pregnancy?

The sources on this page cover biotin taken by mouth. They do not address shampoos or other products used on the hair or skin, which is not a finding either way. Ask your doctor or pharmacist about a specific product.1

Is biotin safe in the first trimester?

NIH gives one adequate intake for pregnancy, 30 mcg a day, with no separate first-trimester amount. The 26-woman trial included 10 women at 6 to 17 weeks and gave 300 mcg a day for 14 days. Ask your doctor before taking more.2,3

Is collagen and biotin safe during pregnancy?

This page covers only the biotin in such a product. Collagen products also carry other ingredients, so read the full panel and ask your doctor or pharmacist about the combination.2

Is a biotin supplement okay during pregnancy?

NIH has set no upper limit for biotin, and none of the sources checked tested high-dose supplements in pregnancy. Whether a supplement is right for you is a question for your doctor.1

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Sources

  1. National Institutes of Health, Office of Dietary Supplements. Biotin: Fact Sheet for Health Professionals. Updated January 10, 2022. Opened 2026-10-07.
  2. National Institutes of Health, Office of Dietary Supplements. Biotin: Fact Sheet for Consumers. Updated January 15, 2021. Opened 2026-10-07.
  3. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. Am J Clin Nutr. 2002;75(2):295-9. A randomized, placebo-controlled trial. Opened 2026-10-11.
  4. U.S. Food and Drug Administration. Testing for Biotin Interference in In Vitro Diagnostic Devices: Guidance for Industry. October 2020. Opened 2026-10-07.
  5. Mock DM. Biotin: From Nutrition to Therapeutics. J Nutr. 2017;147(8):1487-1492. A review. Opened 2026-10-11.
  6. Moerman A, Delanghe JR. Sense and nonsense concerning biotin interference in laboratory tests. Acta Clin Belg. 2022;77(1):204-210. Opened 2026-10-07.
  7. Goodrum JM, Nair VS, Moore C, Crouch AK, Eichner D, Miller GD. Impact of Biotin Supplementation on Human Chorionic Gonadotropin Immunoassays Utilizing Biotin-Streptavidin Binding Methods in Urine. Clin Chem. 2023;69(7):754-762. A placebo-controlled trial in 10 men. Opened 2026-10-11.
  8. Levothyroxine sodium tablets: prescribing information (Cardinal Health 107, LLC). DailyMed, U.S. National Library of Medicine. Published September 24, 2026. Opened 2026-10-07.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.