Summary
Leucine supplementation has reached Preclinical as its most advanced recorded development stage across any indication, and the database holds no approval for Sarcopenia. ClinicalTrials.gov lists 8 registered trials linking Leucine supplementation to Sarcopenia: 3 are currently recruiting; 4 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT06121492). The largest enrolment is 90 participants (NCT06991855). Registration activity spans 2007 to 2025. The literature layer holds 6 publications for this pair: 3 Cochrane reviews, 1 meta-analysis and 2 clinical trial publications. Publication years run from 2015 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 Sarcopenia ranks 82 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those.
Evidence table
| Evidence tier | C · Preliminary |
|---|---|
| Evidence score | 50.0 (trials 22.0, literature 23.0, tier 5, approved bonus 0.0) |
| Registered trials | 8 total: 3 recruiting, 0 active / not yet recruiting, 4 completed, 1 other |
| Linked publications | 6 (3 Cochrane reviews, 2 clinical trial publications, 1 meta-analysis) |
| Agent type | Supplement |
| Development stage (any indication) | Preclinical |
| Mechanism / class | Reversing decline in aging muscles: expected trends, impacts and remedies · Halma M, Marik P, Varon J, Tuszynski J · 2025 |
| Data sources | OSMF Chronic Disease Review |
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trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5).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 |
|---|---|---|---|---|
| NCT06121492 | Oral Branched-chain Amino Acid Supplementation for Cirrhotic Patients With Sarcopenia 2023 | enrolling by invitation | Phase 3 | 86 |
| NCT03860194 | Effects of Dietary Supplements on Sarcopenic Elders 2017 | completed | Not applicable | 85 |
| NCT04309292 | Protein and Skeletal Muscle in Older Twins: Role of the Gut Microbiome 2021 | completed | Not applicable | 71 |
| NCT01757340 | Calorie Restriction With Leucine Supplementation 2012 | completed | Not applicable | 43 |
| NCT00807508 | Leucine Supplementation in Elderly Men 2007 | completed | PHASE1, PHASE2 | 29 |
| NCT06971822 | Assessing the Impact of a Leucine Enriched Whey Protein vs Isonitrogenous Whey on Muscle Protein Synthetic Responses in the Rested and Acute Post Exercise States in Older Adults 2025 | recruiting | Not applicable | 30 |
| NCT06991855 | Effects of Nutritional Supplementation of Leucine and Polyunsaturated Fatty Acids on Muscle Health in the Elderly 2025 | recruiting | Not applicable | 90 |
| NCT03815201 | Protein Supplementation and Muscle Function in the Elderly 2017 | status unknown | Not applicable | 41 |
Published literature
- Meta-analysis Effects of Leucine Supplementation in Older Adults with Sarcopenia: A Meta-AnalysisHuang C, Hsieh MH · Nutrients · 2025 · PMID 40805998
- Cochrane review Effect of supplementation with leucine alone, with other nutrients or with physical exercise in older people with sarcopenia: a systematic reviewConde Maldonado E, Marqués-Jiménez D, Casas-Agustench P et al. · Endocrinologia, diabetes y nutricion · 2022 · PMID 36396594
- Clinical trial publication Supplement-based nutritional strategies to tackle frailty: A multifactorial, double-blind, randomized placebo-controlled trialRoschel H, Hayashi AP, Fernandes AL et al. · Clinical nutrition (Edinburgh, Scotland) · 2021 · PMID 34358827
- Clinical trial publication Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical TrialMartínez-Arnau FM, Fonfría-Vivas R, Buigues C et al. · Nutrients · 2020 · PMID 32230954
- Cochrane review Beneficial Effects of Leucine Supplementation on Criteria for Sarcopenia: A Systematic ReviewMartínez-Arnau FM, Fonfría-Vivas R, Cauli O · Nutrients · 2019 · PMID 31627427
- Cochrane review Effects of leucine-rich protein supplements on anthropometric parameter and muscle strength in the elderly: a systematic review and meta-analysisKomar B, Schwingshackl L, Hoffmann G · The journal of nutrition, health & aging · 2015 · PMID 25809808
Mechanism and notes
Recorded mechanism or class: Reversing decline in aging muscles: expected trends, impacts and remedies · Halma M, Marik P, Varon J, Tuszynski J · 2025.
OSMF's existing evidence tier for this pair is C (Preliminary), derived from the strength of the disease association recorded in OSMF Chronic Disease Review. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Leucine supplementation approved for Sarcopenia?
Leucine supplementation has reached Preclinical as its most advanced recorded development stage across any indication, and the database holds no approval for Sarcopenia. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Leucine supplementation in clinical trials for Sarcopenia?
ClinicalTrials.gov lists 8 registered trials linking Leucine supplementation to Sarcopenia: 3 are currently recruiting; 4 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT06121492). The largest enrolment is 90 participants (NCT06991855). Registration activity spans 2007 to 2025.
What does the evidence show for Leucine supplementation in Sarcopenia?
Leucine supplementation has both completed registered trials and synthesis-level publications linked to Sarcopenia. 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 C (Preliminary), derived from the strength of the disease association recorded in OSMF Chronic Disease Review. 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.