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Updated: Aug 7, 2025

Author Spotlight: In Vivo Assessment of Thyroid Hormone Disruption Using the THAI Mouse Model
Published on: October 6, 2023
Thyroid Hormone Abuse Among Elite Athletes
David J Handelsman1,2, Matti Gild3,4,5, Roderick Clifton-Bligh3,4,5
1ANZAC Research Institute, University of Sydney, Sydney, NSW 2139, Australia.
Context:
Thyroid hormone (TH) abuse for performance enhancement in sport remains controversial and it is not prohibited in sports under the World Anti-Doping Code. However, the prevalence of TH usage in athletes is not known.
Objective:
We investigated TH use among Australian athletes undergoing antidoping tests for competition in World Anti-Doping Agency (WADA)-compliant sports by measuring TH in serum and surveying mandatory doping control form (DCF) declarations by athletes of all drugs used in the week prior to the antidoping test.
Methods:
Serum thyroxine (T4), triiodothyronine (T3), and reverse T3 were measured by liquid chromatography-mass spectrometry and serum thyrotropin, free T4, and free T3 by immunoassays in 498 frozen serum samples from antidoping tests together with a separate set of 509 DCFs.
Results:
Two athletes had biochemical thyrotoxicosis giving a prevalence of 4 per 1000 athletes (upper 95% confidence limit [CL] 16). Similarly, only 2 of 509 DCFs declared usage of T4 and none for T3, also giving a prevalence of 4 (upper 95% CL 16) per 1000 athletes. These estimates were consistent with DCF analyses from international competitions and lower than the estimated T4 prescription rates in the age-matched Australian population.
Conclusion:
There is minimal evidence for TH abuse among Australian athletes being tested for competing in WADA-compliant sports.
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