Levothyroxine
Also known as: synthroid
Overview
Deep dive
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Known interactions
- Compound-pair ruleCaution
Calcium reduces absorption of thyroid medication when taken together.
Separate by about 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Iron reduces absorption of thyroid medication when taken together.
Separate by about 4 hours.
Suggested separation: 4 h
- Category rule: supplement × medicationNote
Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).
Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist.
- Category rule: vitamin × medicationNote
Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).
Specific pairs are checked against a licensed source; confirm with your provider.
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Divalent cations chelate levothyroxine in the gut and reduce absorption by up to 30%.
Take levothyroxine on empty stomach; separate mineral supplements by at least 4 hours.
Suggested separation: 4 h
- Compound-pair ruleCaution
Reduced gastric acid impairs levothyroxine absorption.
Monitor TSH after starting/stopping PPI; dose adjustment may be needed.
- Compound-pair ruleCaution
Reduced gastric acid impairs levothyroxine absorption.
Monitor TSH after starting/stopping PPI; dose adjustment may be needed.
- Compound-pair ruleCaution
Reduced gastric acid impairs levothyroxine absorption.
Monitor TSH after starting/stopping PPI; dose adjustment may be needed.
- Compound-pair ruleCaution
Reduced gastric acid impairs levothyroxine absorption.
Monitor TSH after starting/stopping PPI; dose adjustment may be needed.
- Compound-pair ruleCaution
Reduced gastric acid impairs levothyroxine absorption.
Monitor TSH after starting/stopping PPI; dose adjustment may be needed.
- Compound-pair ruleNote
Ashwagandha can raise T4/T3 levels and may amplify thyroid medication effect.
Monitor TSH when starting ashwagandha on levothyroxine.
- Compound-pair ruleNote
May raise thyroid hormone; can amplify levothyroxine effect.
Monitor TSH when combining.
Frequently asked
Sources referenced
Stackwise compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician.
Related compounds
Others in the medication category or studied for the same goals.
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