Research · PMID 38260143
Reviewed by Neal Rouzier, MD, Preventive Medicine · Sep 2026
Natural desiccated thyroid for the treatment of hypothyroidism?
Frontiers in endocrinology · January 2023 · Adrian H Heald, Peter Taylor, Lakdasa Premawardhana, Mike Stedman, Colin Dayan
What this study found
Primary hypothyroidism affects about 3% of the general population in Europe. Early treatments in the late 19 th Century involved subcutaneous as well as oral administration of thyroid extract.
How RAGMD uses this study
Clinical questions this paper informs
Synthesis lives on the evidence question — this page shows where the study sits in that analysis.
Core study
Is desiccated thyroid extract superior to levothyroxine for hypothyroidism?
Levothyroxine is standard first-line therapy with the strongest outcome evidence. Desiccated thyroid extract lacks modern RCT data demonstrating superiority and has variable hormone content between batches.
Open evidence analysisSupporting literature
Does combination T3/T4 therapy improve symptoms versus levothyroxine alone?
Randomized trials and meta-analyses show inconsistent symptom benefit from adding liothyronine to levothyroxine compared with levothyroxine monotherapy. Guidelines generally recommend levothyroxine as first-line therapy.
Open evidence analysisSupporting literature
Should subclinical hypothyroidism be treated with levothyroxine?
The TRUST trial found no meaningful symptom or quality-of-life benefit from levothyroxine in older adults with subclinical hypothyroidism. Treatment may still be considered with very high TSH, pregnancy plans, or specific clinical contexts.
Open evidence analysisSupporting literature
What TSH target is appropriate for treated hypothyroidism?
Most guidelines suggest maintaining TSH within the reference range on levothyroxine, often near the lower half for many patients. Pregnancy and specific comorbidities require tighter targets.
Open evidence analysisSupporting literature
Does treated hypothyroidism fully explain difficulty losing weight?
Hypothyroidism can contribute to weight gain, but levothyroxine normalization typically yields modest weight loss rather than resolving obesity. Persistent weight difficulty usually involves additional metabolic and behavioral factors.
Open evidence analysisSupporting literature
What factors interfere with levothyroxine absorption?
Levothyroxine absorption is reduced by concurrent iron, calcium, PPIs, and some foods including coffee and fiber. Consistent fasting dosing separated from interfering substances improves TSH stability.
Open evidence analysis