Hashi's antibodies are typically not the direct cause for any hypo symptoms. The antibodies attack the thyroid gland until over an extended period the gland is destroyed. As this is occurring the output of the thyroid gland diminishes and the pituitary secretes increasing amounts of TSH in an effort to stimulate more production of thyroid hormone. Hypothyroidism is correctly defined as "insufficient T3 effect in tissue throughout the body due to inadequate supply of, or response to, thyroid hormone. So insufficient Tissue T3 Effect results in hypothyroid symptoms. There is no biochemical test that should be used as a pass/fail decision about the thyroid status. Diagnosis should be an integrated approach starting with family medical history, evaluation for signs/ symptoms that occur more frequent;ly with hypothyroidism, and extended biochemical testing.
So please tell us about any/all symptoms you have. Also, please post the actual test results and reference ranges shown on the lab reports for those two sets of tests. Just being in range is not necessarily optimal. The ranges are far too broad, due to the erroneous assumptions used to establish ranges. Typically they are also skewed to the low end. So we need to compare actual to reference ranges.
Also, please understand that a 50 mcg dose of T4 med is not additive to your prior levels. The med causes TSH to go down, thus reducing the output of natural thyroid hormone. Since your Free T4 and Free T3 levels are the sum of both natural thyroid hormone and thyroid med, that means small starting doses like that do little/nothing for the patient. Only when the dose is enough that TSH is essentially suppressed below range will additional dose increases start to raise your FT4/FT3 levels. Dosage should be increased as needed to relieve signs/symptoms of hypothyroidism, without creating any signs/symptoms of hyperthyroidism. A recent excellent scientific paper concluded that: " Hypothyroid symptom relief was associated with both a T4 dose giving TSH-suppression below the lower reference limit and FT3 elevated further into the upper half of its reference range."
As noted above Tissue T3 Effect is determined by both the supply of, and response to, thyroid hormone. So in addition to checking FT4/FT3 levels to assess the supply, the response is also important. The response is affected by variables such as cortisol, Reverse T3, Vitamin D, B12 and ferritin. So those need to be tested and optimized as well. Have you been tested for any of those?