This study examined the effects of a single 50-mcg dose of liothyronine (T3) on thyroid hormones, thyroid-stimulating hormone (TSH), and vital signs over four days in 12 healthy euthyroid participants. Triiodothyronine levels peaked at 2.5 hours post-administration, while heart rate significantly increased within 5 hours (p=0.009). TSH suppression was observed
