Patients with subclinical hypothyroidism should not be prescribed thyroid hormone therapy, new international guidelines say.

A panel of clinicians, including an Australian GP academic, issued a “strong recommendation” against the therapy in adults with only slightly elevated TSH levels, 4-10mIU/L, and free thyroxine levels within the normal range.

“Thyroid hormones do not lead to important benefits for adults with [subclinical hypothyroidism] for quality of life or thyroid-related symptoms including depressive symptoms and fatigue,” they wrote.

However, their advice does not apply to pregnant women, those trying to conceive, or those with TSH levels above 20mIU/L.