PMC7193347_01
Changes in FT4, FT3 and TSH levels after the acute ingestion of 5 mg levothyroxine. The levels of FT4 and FT3 measured using ECLIA and ultrafiltration LC-MS/MS, TSH, and the daily dose levothyroxine ingested are shown. LT4, levothyroxine; IA, Electrochemiluminescence immunoassay; MS, ultrafiltration liquid chromatography-tandem mass spectrometry. * > 100 pmol/L
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Fig1
After an additional 4 days, both FT4 and FT3 levels decreased (Fig. 1, Supplementary Table 1).