Low-Dose Naltrexone Is Not Recommended for Thyroid Problems
Low-dose naltrexone (LDN) is not recommended for treating thyroid problems such as hypothyroidism or hyperthyroidism as there is no reliable evidence supporting its efficacy for these conditions. The standard treatments for thyroid disorders remain levothyroxine for hypothyroidism and antithyroid medications, radioactive iodine, or surgery for hyperthyroidism 1.
Evidence on LDN for Thyroid Disorders
Lack of Supporting Evidence
A 2022 review specifically examining alternative approaches to thyroid disease management found that low-dose naltrexone has "little to no evidence of any impact on thyroid disorders" 2.
A quasi-experimental before-after study from 2020 directly investigated whether starting LDN affected thyroid hormone requirements in patients with hypothyroidism. The researchers found "no association between starting LDN and the subsequent dispensing of thyroid hormones" and concluded that their results "do not support claims of efficacy of LDN in hypothyroidism" 3.
Standard of Care for Thyroid Disorders
Hypothyroidism Management
According to clinical guidelines, the principal treatment for hypothyroidism is oral T4 monotherapy (levothyroxine sodium) 1. This is the established standard of care with proven efficacy in managing hypothyroid symptoms and normalizing thyroid function tests.
Hyperthyroidism Management
For hyperthyroidism, treatment options include:
- Antithyroid medications (such as methimazole)
- Nonreversible thyroid ablation therapy (radioactive iodine)
- Surgery
- Treatment decisions are based on TSH levels, cause of hyperthyroidism, and patient characteristics 1
Off-Label Use of Low-Dose Naltrexone
While LDN has been studied for various conditions, its use remains largely experimental:
A 2025 scoping review found that while LDN has been suggested for several conditions, there are significant "gaps in research, pointing to the need for larger clinical trials and proper dosing studies" 4.
Limited evidence supports LDN's safety and tolerability in conditions like multiple sclerosis, fibromyalgia, and Crohn's disease, but efficacy evidence is primarily limited to subjective measures 5.
A 2023 case series examining LDN in postural orthostatic tachycardia syndrome found inconsistent results, with only 3 of 6 patients reporting subjective improvement 6.
Potential Risks and Contraindications
It's worth noting that naltrexone (in standard doses) has established contraindications:
- Should not be used concomitantly with opiate medications 1
- Should be avoided in patients with seizure disorders 1
- Requires monitoring for side effects
Algorithm for Managing Thyroid Disorders
Diagnosis: Confirm thyroid dysfunction through serum TSH testing, with follow-up T4 testing for abnormal TSH results 1
For Hypothyroidism:
- Primary treatment: Levothyroxine sodium (T4) monotherapy
- Dosage adjusted based on TSH levels, aiming for normalization
- Regular monitoring of TSH levels to ensure proper dosing
For Hyperthyroidism:
- TSH < 0.1 mIU/L: Treatment generally recommended, especially for older patients (>60 years) or those with heart disease risk, osteopenia/osteoporosis 1
- TSH 0.1-0.45 mIU/L: Treatment generally not recommended for all patients 1
- Treatment options include antithyroid medications, radioactive iodine, or surgery depending on cause and severity
Conclusion
Patients seeking alternative treatments for thyroid disorders should be advised that low-dose naltrexone lacks scientific evidence for efficacy in thyroid conditions. Standard treatments (levothyroxine for hypothyroidism; antithyroid medications, radioactive iodine, or surgery for hyperthyroidism) remain the evidence-based approach to managing these conditions effectively.