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Medicines and supplements

Can you take chromium with levothyroxine?

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

Ask your pharmacist or doctor before combining. In a small study of seven volunteers, chromium picolinate taken at the same time as levothyroxine lowered the amount of levothyroxine absorbed over 6 hours. NIH lists the interaction, and the levothyroxine label warns that some supplements reduce its absorption.1,2,3

Key facts

  • The study gave seven healthy volunteers 1 mg of levothyroxine, alone or with chromium picolinate, and measured blood thyroxine for 6 hours.1
  • A 2021 systematic review listed the chromium finding among those that need larger, well-designed studies.4
  • The levothyroxine label says iron and calcium supplements and antacids can decrease its absorption.3
  • MedlinePlus asks people on levothyroxine to tell their doctor and pharmacist about all vitamins and nutritional supplements.5

Ask your pharmacist how far apart to take them

In a small study of seven volunteers, chromium picolinate taken at the same time as levothyroxine lowered how much levothyroxine was absorbed over 6 hours. NIH lists this interaction and says it might keep you from getting the full effect of the medicine.1,2,6

Reported in studies

What is documented

Both NIH fact sheets on chromium list levothyroxine among the medicines it might interact with. They rest on one small study, in which chromium picolinate supplements taken at the same time as levothyroxine decreased levothyroxine absorption over 6 hours.2,6

The concern is absorption, the same kind of problem the label describes for calcium and iron. If less levothyroxine gets into the blood, NIH says, you might not get the full effect of the medicine.3,6

How strong the evidence is

The study was small and short: seven healthy volunteers rather than people taking levothyroxine every day, single doses, and 6 hours of blood tests. Its authors still advised people who use both not to take them at the same time.1

A 2021 systematic review of levothyroxine with food, drinks and supplements found 63 studies in all. It grouped chromium with milk, juices and aluminum products as effects that still need larger, well-designed studies.4

Other thyroid medicines

The study and NIH's warning concern levothyroxine. The sources on this page do not address other thyroid medicines. That is not a finding either way, so ask your pharmacist about yours.2

Questions for your pharmacist

  • How should I time chromium, or a multivitamin that contains it, around my levothyroxine?
  • Does my multivitamin also contain calcium or iron?
  • Should my thyroid levels be checked after I start or stop a supplement?

MedlinePlus gives specific spacing instructions for calcium carbonate and iron supplements. Ask whether chromium needs the same treatment in your case, rather than guessing.5

Questions people ask

Does chromium in a multivitamin affect levothyroxine?

The study used chromium picolinate on its own. Multivitamins usually contain 35 to 120 mcg of chromium, and some also contain calcium or iron, which the levothyroxine label says can reduce absorption, so ask your pharmacist about timing.2,3

Is it only chromium picolinate?

The study tested chromium picolinate. The sources on this page do not report on other forms, which is not evidence either way.1

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Sources

  1. John-Kalarickal J, Pearlman G, Carlson HE. New medications which decrease levothyroxine absorption. Thyroid. 2007;17(8):763-765. Opened 2026-10-07.
  2. National Institutes of Health, Office of Dietary Supplements. Chromium: Fact Sheet for Health Professionals. Updated June 2, 2022. Opened 2026-10-07.
  3. Levothyroxine sodium tablets: prescribing information (Cardinal Health 107). DailyMed, U.S. National Library of Medicine. Published September 24, 2026. Opened 2026-10-07.
  4. Wiesner A, Gajewska D, Pasko P. Levothyroxine Interactions with Food and Dietary Supplements: A Systematic Review. Pharmaceuticals (Basel). 2021;14(3):206. Opened 2026-10-07.
  5. MedlinePlus. Levothyroxine. U.S. National Library of Medicine. Last revised February 15, 2019. Opened 2026-10-07.
  6. Office of Dietary Supplements, National Institutes of Health. Chromium: Fact Sheet for Consumers. Updated March 22, 2021. Opened 2026-10-07.

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