Last reviewed 2026-04-20 · How we verify

Euthyrox

At a glance

Approved indications

No approved indications tracked.

Boxed warnings

• WARNING: NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS Thyroid hormones, including EUTHYROX, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for

Common side effects

• Weight loss
• Increased appetite
• Diarrhea
• Tremors
• Nervousness
• Irritability
• Insomnia
• Headache
• Heat intolerance
• Muscle weakness
• Palpitations
• Tachycardia

Serious adverse events

• Myocardial infarction
• Arrhythmias
• Heart failure
• Cardiac arrest
• Angina
• Seizures
• Pseudotumor cerebri
• Slipped capital femoral epiphysis
• Craniosynostosis
• Angioedema

Key clinical trials

• Novel Approaches to the Treatment of Hypothyroidism (PHASE2, PHASE3)
• Comparison of Levothyroxine Formulations in the Treatment of Congenital Hypothyroidism
• Neuroendocrine Response in Pediatric Febrile Seizures
• T4/T3 Therapy in Hypothyroidism (PHASE2)
• SNUH Immune Checkpoint Inhibitor-induced Hypothyroidism Recovery Trial (NA)
• Thyroid Hormone for Treatment of Nonalcoholic Steatohepatitis in Veterans (PHASE2)
• Dosing of LT4 in Older Individuals (PHASE4)
• A Study Evaluation the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Patients With Primary Hypothyroidism (PHASE2)

Primary sources

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