ModerateDietary supplements, plant adaptogens (local classification)×Thyroid hormones
Updated · Methodology
Mechanism
Ashwagandha stimulates thyroid function: in a trial of 50 people with subclinical hypothyroidism, 300 mg twice daily for eight weeks lowered TSH and raised T3 and T4 versus placebo. On top of an already titrated levothyroxine dose, that push adds up. A case of painless thyroiditis with thyrotoxicosis that resolved after stopping the herb has also been published.
Symptoms
Signs of hormone excess: palpitations, fine hand tremor, insomnia, weight loss, heat intolerance, diarrhoea, irritability. The published case also featured night fever and fatigue.
Management
Anyone on levothyroxine should not add ashwagandha without telling whoever titrates the dose. If it is already in use, check TSH, free T4 and T3 at 6–8 weeks and declare the herb at every test: without that detail the result reads as hormone over-replacement and the dose gets cut for the wrong reason. With palpitations or tremor, stop the ashwagandha first.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- AEMPS: Ficha técnica Levotiroxina Aristo 100 microgramos comprimidos EFG (2023)– AEMPS, CIMA, nº registro 84484, sección 4.5
- Cureus: Painless Thyroiditis Induced by Withania somnifera (Ashwagandha) (2024)– Cureus 2024, PMC10981964, клинический случай тиреотоксикоза