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Types of L-Carnitine: Forms & Bioavailability

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest For
L-Carnitine L-Tartrate (LCLT)Moderate (~15-18% oral)Exercise recovery — most researched form for athletic performance and muscle damage reduction
Acetyl-L-Carnitine (ALCAR)Moderate (crosses blood-brain barrier)Brain health — the acetyl group allows it to cross the blood-brain barrier; best for cognitive support
L-Carnitine (base form)Low-Moderate (~14-18%)General use — cheapest form; adequate for general carnitine supplementation
Propionyl-L-Carnitine (GPLC)ModerateCardiovascular / peripheral circulation — some evidence for intermittent claudication and blood flow

L-Carnitine L-Tartrate (LCLT)

Bioavailability: Moderate (~15-18% oral). Best for: Exercise recovery — most researched form for athletic performance and muscle damage reduction.

Acetyl-L-Carnitine (ALCAR)

Bioavailability: Moderate (crosses blood-brain barrier). Best for: Brain health — the acetyl group allows it to cross the blood-brain barrier; best for cognitive support.

L-Carnitine (base form)

Bioavailability: Low-Moderate (~14-18%). Best for: General use — cheapest form; adequate for general carnitine supplementation.

Propionyl-L-Carnitine (GPLC)

Bioavailability: Moderate. Best for: Cardiovascular / peripheral circulation — some evidence for intermittent claudication and blood flow.

Full L-Carnitine Guide

References

  1. (). Responses of criterion variables to different supplemental doses of L-carnitine L-tartrate. Journal of Strength and Conditioning Research. DOI
  2. (). Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. Journal of Physiology. DOI
  3. (). Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's disease. International Clinical Psychopharmacology. DOI