L-Carnitine
Also known as Levocarnitine
L-Carnitine is a naturally occurring amino-acid derivative that transports long-chain fatty acids into mitochondria for beta-oxidation. It is one of the most extensively studied nutritional compounds related to fat metabolism and exercise performance. Meta-analyses of oral supplementation report modest average reductions in body weight and fat mass, generally smaller in magnitude than pharmaceutical weight-management agents. It is widely available as an over-the-counter supplement rather than a prescription therapy.
Reported benefits
- Modest reductions in body weight and fat mass reported in meta-analyses
- May support exercise recovery and reduce exercise-induced muscle damage
- Well-characterized long-term safety profile
- Widely available and inexpensive compared with pharmaceutical alternatives
How it works
L-Carnitine shuttles activated long-chain fatty acids across the inner mitochondrial membrane via the carnitine-acylcarnitine translocase system, a required step for mitochondrial beta-oxidation of fat. Adequate carnitine availability is proposed to support fat-based energy metabolism, particularly during exercise, though endogenous synthesis and dietary intake are typically sufficient in most healthy individuals, which may limit the additional benefit of supplementation.
Dosing ranges
| Tier | Dose | Frequency |
|---|---|---|
| Low | 500 mg | once daily |
| Moderate | 1,000 mg | once or twice daily |
| High | 2,000 mg | divided across two doses daily |
Estimate your dose
Dose estimator
Educational estimate for L-Carnitine, scaled to body size. Not medical advice.
Read before using
This tool produces a rough, educational estimate by scaling commonly-published research ranges to lean body mass. It is not a prescription, medical advice, or a substitute for a licensed clinician. Most peptides use fixed dosing, not weight-based dosing. Individual needs vary. You are solely responsible for how you use this information.
Mixing & syringe units
Target dose follows the estimate above. Change it there, or edit it directly below.
Reconstitution calculator
How much water to add and how many insulin-syringe units to draw for L-Carnitine. Educational only.
Draw to this mark
20,000units
= 200 mL for a 1,000 mg dose
Concentration
5 mg/mL
Doses per vial
0
This dose needs 20,000 units, more than a 100-unit syringe holds. Add more water, split the dose, or use a larger syringe.
A U-100 syringe reads 100 units per mL. This is a reconstitution math helper only, not a prescription or dosing advice. Verify every calculation and consult a qualified healthcare provider.
Possible side effects
Stacking notes
Sometimes combined with exercise or other metabolic supplements; evidence for added benefit from stacking is limited.
Common protocols
Common questions
What is L-Carnitine used for?
L-Carnitine is a naturally occurring amino-acid derivative that transports long-chain fatty acids into mitochondria for beta-oxidation. It is one of the most extensively studied nutritional compounds related to fat metabolism and exercise performance. Meta-analyses of oral supplementation report modest average reductions in body weight and fat mass, generally smaller in magnitude than pharmaceutical weight-management agents. It is widely available as an over-the-counter supplement rather than a prescription therapy. Reported benefits include modest reductions in body weight and fat mass reported in meta-analyses, may support exercise recovery and reduce exercise-induced muscle damage, well-characterized long-term safety profile.
What is a typical L-Carnitine dose?
Reported ranges run 500-2,000 mg. A low protocol is 500 mg once daily, and a high protocol is 2,000 mg divided across two doses daily. This is reference information, not a dosing recommendation.
What is the half life of L-Carnitine?
Approximately 15 hours for oral elimination half-life, based on published pharmacokinetic studies. That is what sets the dosing frequency, and it is why the timing guidance is ~30 min before exercise.
How is L-Carnitine administered?
Oral: by mouth. Intravenous and intramuscular forms are used in some clinical and research settings, but oral supplementation is the most common route for weight-related use.
How long is a L-Carnitine cycle?
Commonly used continuously as a daily supplement on, followed by No established off-cycle is required for typical supplemental doses off.
What are the side effects of L-Carnitine?
Reported side effects include gastrointestinal upset, including nausea and diarrhea, at higher oral doses, a fishy body odor has been reported, related to gut microbial metabolism of carnitine, rare reports of interactions with anticoagulant medications, effects on weight are generally modest and may not be noticeable for all users. Evidence level for this compound is well studied.
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Educational use only, not medical advice. This profile is provided for research and educational purposes. L-Carnitine may be a research compound or a prescription medication; nothing here is intended to diagnose, treat, cure, or prevent any disease. Dosing figures reflect commonly-published research ranges, not a prescription. Consult a qualified healthcare provider before making any health decision. Read the full disclaimer →