Summary
Levothyroxine Sodium has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Hypothyroidism would be drug repurposing rather than first-in-human development. This does not mean it is approved for Hypothyroidism. ClinicalTrials.gov lists 8 registered trials linking Levothyroxine Sodium to Hypothyroidism: 4 have completed; 4 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT01769157). The largest enrolment is 490 participants (NCT05412979). Registration activity spans 2006 to 2022. The literature layer holds 9 publications for this pair: 2 Cochrane reviews, 1 systematic review, 1 randomised controlled trial publication and 5 clinical trial publications. Publication years run from 2002 to 2025. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.
The RepurpOS disease-intelligence file for Hypothyroidism ranks 81 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Hashimoto's (most common cause) is irreversible in majority; spontaneous recovery in <5%; subclinical hypothyroidism spontaneously normalizes in ~30-40% of cases within 2 years without treatment.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 66.0 (trials 20.0, literature 26.0, tier 15, approved bonus 5.0) |
| Registered trials | 8 total: 0 recruiting, 0 active / not yet recruiting, 4 completed, 4 other |
| Linked publications | 9 (5 clinical trial publications, 2 Cochrane reviews, 1 systematic review, 1 randomised controlled trial publication) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | Open Targets, ChEMBL |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT01769157 | Effects of L-carnitine on Hypothyroidism 2012 | completed | Phase 4 | 60 |
| NCT01486667 | Thyroxin Treatment in Sub Clinical Hypothyroidism, on the Apnea Hypopnea Index Score, Lipids and Highly Sensitive CRP 2011 | status unknown | Phase 3 | 200 |
| NCT04124705 | A Study of Armour® Thyroid Compared to Synthetic T4 (Levothyroxine) in Previously Hypothyroid Participants 2019 | completed | Phase 2 | 284 |
| NCT05412979 | A Study Evaluating the Safety and Efficacy of Hormone Replacement Therapy With ST-1891 Compared to Levothyroxine in Patients With Primary Hypothyroidism 2022 | completed | Phase 2 | 490 |
| NCT03106935 | Recurrent Pregnancy Loss and Thyroid Disease 2015 | status unknown | Early Phase 1 | 300 |
| NCT01574859 | Central Hypothyroidism and Cardiovascular Risk 2012 | completed | Not applicable | 200 |
| NCT00488644 | Combined Levothyroxine/Liothyronine Supplementation in Hypothyroid Patients With Brain Tumors 2006 | terminated | Not applicable | 12 |
| NCT05240911 | Individual Dosing of Levothyroxine After Thyroidectomy 2022 | status unknown | Not applicable | 202 |
Published literature
- Clinical trial publication Phase 1 Study Evaluating the Pharmacokinetics, Dose Proportionality, Bioavailability, and Tolerability of Subcutaneous Levothyroxine Sodium (XP-8121)Fitch R, Mould DR, Conoscenti V et al. · Clinical and translational science · 2025 · PMID 40348586
- Clinical trial publication Metaverse Clinic for Pregnant Women With Subclinical Hypothyroidism: Prospective Randomized StudyZheng Y, Chen Y, Chen Y et al. · Journal of medical Internet research · 2025 · PMID 39908543
- Cochrane review Effect of Levothyroxine Therapy on Gestational Hypertension and Pre-eclampsia in Pregnant Women with Subclinical Hypothyroidism, Hypothyroidism, and Thyroid Autoimmunity: A Systematic Review and Meta-analysisGoodarzi-Khoigani M, Aminorroaya A, Mohammadi R · Cardiovascular & hematological disorders drug targets · 2025 · PMID 39976090
- Cochrane review Systematic review and meta-analysis of the efficacy and pregnancy outcomes of levothyroxine sodium tablet administration in pregnant women complicated with hypothyroidismGeng X, Chen Y, Wang W et al. · Annals of palliative medicine · 2022 · PMID 35523752
- Clinical trial publication A Pivotal Field Study to Support the Registration of Levothyroxine Sodium Tablets for Canine HypothyroidismLewis VA, Morrow CMK, Jacobsen JA et al. · Journal of the American Animal Hospital Association · 2018 · PMID 29757661
- Clinical trial publication Are multisource levothyroxine sodium tablets marketed in Egypt interchangeable?Abou-Taleb BA, Bondok M, Nounou MI et al. · Annales d'endocrinologie · 2018 · PMID 29289332
- Clinical trial publication [Treatment of thirty primary hypothyroidism patients by fuzheng fujia mixture ]Chun-hong L, Wen-hui C, Lin-na Z · Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine · 2012 · PMID 23359970
- Randomized controlled trial Effects of evening vs morning levothyroxine intake: a randomized double-blind crossover trialBolk N, Visser TJ, Nijman J et al. · Archives of internal medicine · 2010 · PMID 21149757
- Systematic review Starting dose of levothyroxine for the treatment of congenital hypothyroidism: a systematic reviewHrytsiuk I, Gilbert R, Logan S et al. · Archives of pediatrics & adolescent medicine · 2002 · PMID 11980555
Mechanism and notes
No mechanism of action is recorded for this pair in the source databases.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Levothyroxine Sodium approved for Hypothyroidism?
Levothyroxine Sodium has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Hypothyroidism would be drug repurposing rather than first-in-human development. This does not mean it is approved for Hypothyroidism. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Levothyroxine Sodium in clinical trials for Hypothyroidism?
ClinicalTrials.gov lists 8 registered trials linking Levothyroxine Sodium to Hypothyroidism: 4 have completed; 4 are terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT01769157). The largest enrolment is 490 participants (NCT05412979). Registration activity spans 2006 to 2022.
What does the evidence show for Levothyroxine Sodium in Hypothyroidism?
Levothyroxine Sodium has both completed registered trials and synthesis-level publications linked to Hypothyroidism. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-05. Page built 2026-10-07.