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Influence of drugs on thyroid values

Thyroid and drugs Part 1

The first of a series of three articles on the influence of drugs on the thyroid gland discusses the influence that drugs can have on the findings of laboratory assessments of thyroid values. It particularly focuses on the question whether this could lead to incorrect diagnoses and unjustified treatment. Is it possible that a lab finding suggests a thyroid disorder whereas there is no actual disorder present? Many drugs are known to influence the values of the thyroid hormones (T4 and T3), but effects on the value of thyroid stimulating hormone (TSH) are rare. Since TSH assessment is the cornerstone of diagnostic workup when a thyroid disorder is suspected, a disorder can be virtually excluded if the TSH value is within normal limits. Only amiodarone and biotin are known to be able to affect TSH values. This can lead to confusion in interpreting a lab finding. 

  • Various drugs are known to affect the values of T3 and T4. Drugs rarely cause abnormal TSH findings.
  • The use of amiodarone or biotin (vitamin B8) can result in abnormal TSH values in  the absence of disturbed thyroid function.
  • In view of possibly abnormal TSH values, it is important for doctors to be aware of a patient’s drug use, including the use of over-the-counter drugs that might affect the diagnostics.
  • Biotin is a dietary supplement that is freely available and is hence usually not listed on an overview of drugs used by a patient. 

  1. Van Lieshout J, Felix-Schollaart B, Bolsius EJM, Boer AM, Burgers JS, Bouma M, Sijbom M. NHG-Standaard Schildklieraandoeningen (M31). Nederlands Huisartsen Genootschap. Versie 2.0, juni 2013. Available from: Accessed 23-05-2021
  2. Burch HB. Drug Effects on the Thyroid. N Engl J Med. 2019 Aug 22;381(8):749-761. doi: 10.1056/NEJMra1901214. 
  3. Burch HB. Drug Effects on the Thyroid. Reply. N Engl J Med. 2019 Nov 14;381(20):1980-1981. doi: 10.1056/NEJMc1912672. 
  4. Geneesmiddel Informatie Centrum. Contra-indicatie hypothyreoïdie, hyperthyreoïdie / Interacties thyreomimetica en thyreostatica. In: KNMP G-standaard, available from: KNMP Kennisbank. Accessed 04-06-2021
  5. Stichting Health Base. Contra-indicatie hypothyreoïdie, hyperthyreoïdie/Interacties thyreomimetica en thyreostatica. In: Borgsteede SD, Pham TKL, Eimermann VM, De Klerk S, Tsoi KY. Commentaren Medicatiebewaking. Stichting Health Base. Available from: Accessed 04-06-2021.
  6. Lansbergen GW, Frasa MA, Lentjes EG. Schildklierdiagnostiek en valkuilen; oplettendheid is geboden. Ned Tijdschr Klin Chem Labgeneesk. 2017;42(3): 89-99.
  7. Ross, D.S. (2020). Euthyroid hyperthyroxinemia and hypothyroxinemia. In D.S. Cooper & J.E. Mulder (Eds.), UptoDate. Available from:
  8. Nederlandse Internisten Vereniging (NIV). Richtlijn Schildklierfunctiestoornissen. Revisie 2012. Available from:
  9. Bartalena L, Bogazzi F, Chiovato L, Hubalewska-Dydejczyk A, Links T, P, Vanderpump M. 2018 European Thyroid Association (ETA) Guidelines for the Management of Amiodarone-Associated Thyroid Dysfunction. Eur Thyroid J 2018;7:55-66. doi: 10.1159/000486957
  10. Nademanee K, Singh BN, Callahan B, Hendrickson JA, Hershman JM. Amiodarone, thyroid hormone indexes, and altered thyroid function: long-term serial effects in patients with cardiac arrhythmias. Am J Cardiol. 1986 Nov 1;58(10):981-6. doi: 10.1016/s0002-9149(86)80023-6.
  11. Voedingscentrum. Biotine. Available from: Accessed 04-06-2021.
  12. Thompson KG, Kim N. Dietary supplements in dermatology: A review of the evidence for zinc, biotin, vitamin D, nicotinamide, and Polypodium. J Am Acad Dermatol. 2021 Apr;84(4):1042-1050. doi: 10.1016/j.jaad.2020.04.123.
  13. Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017 Aug;3(3):166-169. doi: 10.1159/000462981.
  14. Li D, Rooney MR, Burmeister LA, Basta NE, Lutsey PL. Trends in Daily Use of Biotin Supplements Among US Adults, 1999-2016. JAMA. 2020 Aug 11;324(6):605-607. doi: 10.1001/jama.2020.8144.
  15. van den Berg R, Slim CL, Lutgers HL, de Heide LJM, Wolthuis A. Schijnbare thyreotoxicose door gebruik van biotine in hoge dosis. Ned Tijdschr Geneeskd. 2018 Feb 14;162:D2358.
  16. Paketçi A, Köse E, Gürsoy Çalan Ö, Acar S, Teke P, Demirci F, et al. Serum Level of Biotin Rather than the Daily Dosage Is the Main Determinant of Interference on Thyroid Function Assays. Horm Res Paediatr. 2019;92(2):92-98. doi: 10.1159/000502740.
  17. Piketty ML, Polak M, Flechtner I, Gonzales-Briceño L, Souberbielle JC. False biochemical diagnosis of hyperthyroidism in streptavidin-biotin-based immunoassays: the problem of biotin intake and related interferences. Clin Chem Lab Med. 2017 May 1;55(6):780-788. doi: 10.1515/cclm-2016-0606.
  18. Biscolla RPM, Chiamolera MI, Kanashiro I, Maciel RMB, Vieira JGH. A Single 10 mg Oral Dose of Biotin Interferes with Thyroid Function Tests. Thyroid. 2017 Aug;27(8):1099-1100. doi: 10.1089/thy.2016.0623.
  19. Erasmus MC. 1 februari 2018. Biotine interferentie. Available from: Accessed 28-07-2021


  • Suzanne de Klerk
  • Gideon Lansbergen
  • Thiemo F. Veneman
  • Sander D. Borgsteede