The Study
Adding L-Carnitine and Selenium to Methimazole in Graves’ Disease: A Prospective Randomized Trial on Thyroid Markers and Quality of Life
This study is like a fair test where half the people got a special vitamin mix with their medicine, and half didn’t. The results show the vitamin mix helped some things—like lowering harmful antibodies faster—but didn’t help everything, like overall energy or mood. We can’t say it definitely caused these changes because people knew who got the vitamins, which might have influenced how they felt.
Analysis score
Maximum 45 for a randomized controlled trial.
Where the score came from
Doctors gave some patients with an overactive thyroid a daily pill with L-carnitine and selenium along with their regular medicine, and others got just the regular medicine.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 545 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — patients needed less long-term medication, recovered faster, and had fewer troubling symptoms, which could mean fewer side effects and better quality of life.
- 2The group with the extra pills had 63% chance of getting better without surgery (vs.
- 313% without), cleared harmful antibodies 2.3x faster (9 vs.
- 414 months), used 36% less medicine, and felt better in specific ways like less shaking and heat sensitivity.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2025
Authors
M. Rossi, Letizia Meomartino, M. Zavattaro, Gloria Selvatico, Ruth Rossetto Giaccherino, Loredana Pagano
Related Content
Claims (6)
In adults newly diagnosed with Graves' disease, adding 500 mg of L-carnitine and 83 mcg of selenium to methimazole reduces the severity of specific symptoms including tremor, irritability, mood swings, heat intolerance, and shortness of breath during exertion, without changing the total number of symptoms experienced.
Adults with newly diagnosed Graves' disease who take L-carnitine and selenium along with methimazole experience spontaneous remission at a rate of 63.3%, while those taking methimazole alone experience remission at a rate of 13.3%.
In people newly diagnosed with Graves' disease, taking L-carnitine and selenium along with methimazole does not change how quickly their thyroid hormone levels return to normal compared to taking methimazole alone.
In adults newly diagnosed with Graves' disease, adding 500 mg L-carnitine and 83 mcg selenium to methimazole shortens the time for harmful antibodies to become undetectable from 13.6 months to 9.1 months, leading to a 2.35-fold faster reduction in these antibodies and a lower rate of disease recurrence and eye complications.
In adults newly diagnosed with Graves' disease, taking 500 mg of L-carnitine and 83 mcg of selenium along with methimazole results in a 36% reduction in total methimazole exposure over time, without affecting the normalization of thyroid hormone levels.
Taking 2,000 to 4,000 milligrams of L-carnitine per day reduces the amount of thyroid hormones entering cells, which lowers the metabolic activity driven by these hormones.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.