I suggest you read this line to your OWN benefit:
Guidelines from leading endocrinology organizations now recommend considering combination therapy for patients with persistent symptoms despite adequate LT4 dosing.
That is, if the endocrinology organization your doctor is referring to does NOT recommend the consideration of combination therapy, then they are obviously NOT a LEADING organization. They are some rather second-rate outfit that is out of date...
Shared Decisionmaking in the Treatment of Hypothyroidism.
Bianco AC 1
Author information
Clinical Endocrinology, 12 Mar 2025,
doi.org/10.1111/cen.15228 PMID: 40077932
Abstract
Hypothyroidism, a condition characterized by an underactive thyroid gland, affects millions worldwide, leading to cognitive and metabolic slowdowns. It is most prevalent in women and older adults, with causes including autoimmune thyroiditis, surgical thyroidectomy, and certain medications. The standard treatment involves synthetic levothyroxine (LT4) monotherapy, which alleviates symptoms by converting to the active hormone, T3. However, some patients continue to experience symptoms such as fatigue, mood disturbances, and poor quality of life despite normalized TSH levels. This persistence of symptoms may stem from misdiagnosis, inadequate dosing, or incomplete normalization of thyroid hormone signaling. Research suggests that LT4 monotherapy may not fully restore T3 levels, leading to suboptimal symptom control. Consequently, combination therapy with LT4 and liothyronine (LT3) has been proposed as an alternative, aiming to balance T4 and T3 levels more effectively. Although randomized controlled trials have not identified significant differences in patient-reported outcomes between LT4 monotherapy and combination therapy, they indicate that patients may prefer the latter. Guidelines from leading endocrinology organizations now recommend considering combination therapy for patients with persistent symptoms despite adequate LT4 dosing. A patient-centered approach, emphasizing shared decision-making and individualized treatment plans, is essential for optimizing outcomes in hypothyroidism management. Further research is needed to refine dosing strategies and identify the patients who would benefit most from combination therapy.
Open access:
europepmc.org/article/MED/4...
onlinelibrary.wiley.com/doi...
PS I'd use a hyphen to make it Decision-making - but I'd rather quote absolutely accurately.