An imbalance of thyroid hormones, specifically hypothyroidism or thyroid hormone conversion disorders, can make it difficult or impossible to lose weight. (holtorfmed.com)
Essentially under stress response thyroid hormone conversion is going to be down regulated to peripheral tissues. (bengreenfieldfitness.com)
They suppress thyroid hormone conversion in the liver.They also increase Reverse T3 production. (forefronthealth.com)