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Acetyl-L-Carnitine (ALCAR) Side Effects & Safety

Evidence:Moderate
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Mild GI discomfort (nausea, stomach upset)
  • Restlessness or insomnia if taken late in the day
  • Fishy body odor at higher doses
  • Possible agitation in individuals with bipolar disorder

Drug & Supplement Interactions

  • Anticoagulants (warfarin) — may enhance anticoagulant effects
  • Thyroid medications — may increase thyroid hormone sensitivity
  • MAO inhibitors — theoretical interaction; use with caution
  • Seizure medications — may alter seizure threshold in rare cases

Maximum Dose

Do not exceed: 3 g/day is the typical maximum used in clinical trials

Full Acetyl-L-Carnitine (ALCAR) Guide

References

  1. Veronese N, Stubbs B, Solmi M, et al. (2018). Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis. Psychosomatic Medicine. DOI PubMed
  2. Li S, Li Q, Li Y, et al. (2015). Acetyl-L-carnitine in the treatment of peripheral neuropathic pain: a systematic review and meta-analysis. Journal of the Peripheral Nervous System. DOI PubMed
  3. Montgomery SA, Thal LJ, Amrein R. (2003). 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 PubMed
  4. Tejani AM, Wasdell M, Spiwak R, Rowell G, et al. (2010). Carnitine for fatigue in multiple sclerosis.. The Cochrane database of systematic reviews. DOI PubMed