L-Carnitine L-Tartrate
Also known as: LCLT, L-carnitine L-tartrate, L-Carnitine L Tartrate
Randomised trials report that 2–3 g/day LCLT given for weeks can attenuate blood markers of muscle damage and oxidative stress and reduce MRI-assessed muscle disruption after eccentric or high-repetition resistance exercise. Some studies report reduced perceived exertion and improved work capacity in specific high-intensity tests; other trials, including a 24-week study in older women at 1.5 g/day, found no effect on muscle strength or inflammatory markers.
Last reviewed: 2026-10-14 · 5 indexed studies
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Overview
L-carnitine L-tartrate (LCLT) is an orally administered carnitine salt commonly used in sports nutrition. Human trials have tested daily doses typically in the 2–3 g range and reported effects on markers of muscle damage and recovery, while effects on strength or muscle mass in older adults have been inconsistent.
Mechanism & Function
Mechanism of Action
L-carnitine is involved in mitochondrial fatty acid transport and may influence the acetyl-CoA/CoA ratio, oxidative stress, and purine catabolism during and after intense exercise; LCLT supplementation increases plasma free carnitine concentrations, which plausibly affects muscle metabolic responses to exercise.
Physiological Role
Supports cellular fatty acid handling and mitochondrial metabolism; may modulate exercise-induced oxidative stress and markers of muscle membrane disruption.
Primary Pathways
Performance / Health Relevance
Evidence most consistently supports a role in reducing biochemical and imaging markers of muscle damage and oxidative stress after resistance exercise, which may translate to faster recovery in some contexts. Effects on strength, hypertrophy or functional outcomes are less consistent.
Evidence Review
Practical Use & Dosage
- Minimum Effective Dose
- Approximately 2 g/day (based on trials reporting attenuation of muscle damage markers).
- Optimal Range
- 2–3 g/day in most positive trials; some acute studies used 3–4 g single doses.
- Upper / Caution Level
- Not established from the provided studies.
- Timing
- Chronic daily supplementation for multiple weeks (many trials used 3 weeks or longer); some acute protocols evaluated single higher doses.
- Best Format
- Oral L-carnitine L-tartrate (powder or capsule).
- Bioavailability
- Supplementation increases plasma free carnitine concentrations in humans.
- Absorption Considerations
- Not established in the provided abstracts.
Safety & Interactions
Side Effects
- •No adverse effects reported in short-term trials included in these abstracts.
Contraindications
- None reported in the provided studies.
Drug Interactions
- •Not reported in the provided studies.
Who Should Avoid
- •Individuals with medical conditions or taking medications should consult a healthcare professional before use.
Monitoring
Not established from the provided studies.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is L-Carnitine L-Tartrate typically used or indicated?
L-Carnitine L-Tartrate is most commonly used for: Support recovery from resistance exercise, Reduce exercise-induced muscle damage and oxidative stress markers, Increase plasma free carnitine. Supports cellular fatty acid handling and mitochondrial metabolism; may modulate exercise-induced oxidative stress and markers of muscle membrane disruption.
How does L-Carnitine L-Tartrate work?
L-carnitine is involved in mitochondrial fatty acid transport and may influence the acetyl-CoA/CoA ratio, oxidative stress, and purine catabolism during and after intense exercise; LCLT supplementation increases plasma free carnitine concentrations, which plausibly affects muscle metabolic responses to exercise.
What is the recommended dose of L-Carnitine L-Tartrate?
The optimal range is 2–3 g/day in most positive trials; some acute studies used 3–4 g single doses.. with a minimum effective dose of Approximately 2 g/day (based on trials reporting attenuation of muscle damage markers).. Best taken: Chronic daily supplementation for multiple weeks (many trials used 3 weeks or longer); some acute protocols evaluated single higher doses.. Upper / caution level: Not established from the provided studies..
What are the side effects of L-Carnitine L-Tartrate?
Reported side effects include: No adverse effects reported in short-term trials included in these abstracts.. Monitoring: Not established from the provided studies.
Does L-Carnitine L-Tartrate interact with medications?
Known or theoretical interactions: Not reported in the provided studies.. Always check with a clinician before combining with prescription medication.
Who should avoid L-Carnitine L-Tartrate?
L-Carnitine L-Tartrate is generally not recommended for: Individuals with medical conditions or taking medications should consult a healthcare professional before use.; and None reported in the provided studies..
How strong is the evidence for L-Carnitine L-Tartrate?
Evidence level: Moderate (overall score 59/100), based on 5 indexed studies on SuppIndex.
Research & References (5)
Effect of Acute and Chronic Oral l-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review.
Systematic review of oral l-carnitine forms (including LCLT) assessing effects on moderate- and high-intensity exercise; included 11 trials (three used LCLT). Chronic dosing ranged 1–3 g/day; acute dosing 3–4 g.
L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress.
Randomised, crossover trial in 10 resistance-trained men given 2 g/day LCLT for 3 weeks; assessed blood markers and MRI after squat exercise.
l-Carnitine Supplementation in Older Women. A Pilot Study on Aging Skeletal Muscle Mass and Function.
Double-blind RCT in healthy women aged 65–70 given 1.5 g/day LCLT or placebo for 24 weeks; measured plasma carnitine, inflammatory markers, IGF-1, body composition and muscle strength.
Safety measures of L-carnitine L-tartrate supplementation in healthy men.
Balanced, placebo-controlled crossover safety study in 10 healthy active men taking 3 g/day LCLT for 3 weeks; assessed clinical chemistries and blood counts.
Effects of L-carnitine L-tartrate supplementation on muscle oxygenation responses to resistance exercise.
Randomised, crossover, double-blind trial in nine resistance-trained men given 2 g/day LCLT for 23 days; muscle oxygenation via NIRS and markers of membrane damage measured during/after squat exercise.
Related Ingredients
Other top-rated ingredients in Ergogenic Compounds.
Creatine Monohydrate
94/100A naturally occurring nitrogenous organic acid that facilitates recycling of adenosine triphosphate (ATP) in muscle and brain tissue via the phosphocreatine shuttle.
Maltodextrin
78/100Short-chain α-1,4 linked glucose polymer that is rapidly hydrolysed by brush-border maltase to glucose; near-equivalent glycaemic response to glucose but lower osmolality at concentration.
Cyclic Dextrin (HBCD)
72/100Produced via cyclic-glucanotransferase action on amylopectin, HBCD forms cluster-like macromolecules ~160 kDa that solubilise at low osmolality (≈4 mOsm/L) and clear the stomach faster than maltodextrin or glucose polymers.
Research Overview
Moderate EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/l-carnitine-l-tartrate
SuppIndex. (2026). L-Carnitine L-Tartrate: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/l-carnitine-l-tartrate
Based on 5 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Studies excluded multi-ingredient trials; effects reported are for LCLT alone. Combine cautiously with other carnitine forms only if evidence supports additive benefit.