T4-only medications such as Synthroid, Levothyroxine, and Tirosint do not give you all the thyroid hormones that your thyroid would normally produce. Your thyroid produces T1, T2, T3, T4 and Calcitrol, or the active form of vitamin D.
T4-only medications cause hair loss, chronic pain and may not do anything meaningful with your free t3 levels, especially if you have liver problems and/or gut problems and aren’t converting. I have yet to see anyone with optimal free T3 and optimal reverse T3 on a T4-only medication.
If you are unable to convert to free T3 effectively, especially with liver and gut problems, T4-only medications are only going to exacerbate your problems.
T4-only medications cause high reverse t3, especially in the face of past starvation diets, and low carb and vegan lifestyles. Other causes can include iron and cortisol and adrenal problems. High reverse T3 will block the free t3 from entering the cells, making you even more hypo and more symptomatic. You may experience hair loss, dry skin, dry hair, adrenal and cortisol issues, low iron, low minerals, low stomach acid, etc. The doctor may increase your meds, and it may make your symptoms even worse.
Why are doctors so reliant and driven to prescribe T4-only medications? Simplicity. They feel that they understand the precise dose and effects of T4-only medications, plus they are probably only following TSH levels, which tell us literally nothing about what is really going on with our thyroid hormones. They will also tell you that Natural Dessicated Thyroid, or NDT such as Armour Thyroid and NP and WP Thyroid, are not precise in dosage or not approved by the FDA, despite the fact that these medications have been successfully prescribed for well over a century.
