Skip to content
DE
Amino acid derivative

L-Carnitine

L-carnitine is a compound the body makes from the amino acids lysine and methionine and also gets from meat. It carries fatty acids into the mitochondria to be burned for energy.

Also listed as Acetyl-L-Carnitine, ALCAR, Acetylcarnitine, L-Carnitine-L-Tartrate

LongevityImmune SupportCognitionEnergyFitness

What can go wrong?

NIH reports nausea, vomiting, cramps, diarrhea, and a fishy body odor at around 3 g/day. Carnitine may cause seizures in people with seizure disorders and muscle weakness in people with uremia. No tolerable upper intake level has been established; that does not mean an unlimited intake is safe. 1

Why does TMAO come up?

Gut bacteria can convert carnitine into compounds that lead to TMAO, a substance associated with cardiovascular risk. NIH treats the long-term implications as unresolved. This concern sits alongside trials of possible cardiovascular benefits, so carnitine’s role in energy production alone cannot settle its long-term safety. 1

Medicines can alter carnitine status

Long-term use of pivalate-containing antibiotics can deplete carnitine. NIH advises people taking regular medicines to discuss carnitine intake with their healthcare professional. Kidney disease can also change production and losses; findings from dialysis treatment are not a guide to self-treatment. 1

Valproic acid and several other antiseizure medicines can lower blood carnitine. Intravenous carnitine has also been investigated for valproic-acid toxicity, but the optimal regimen remains uncertain. That is a clinical treatment question, not a reason to adjust seizure medication or add a supplement independently. 1

For information, not individual medical advice. Ingredient studies do not establish the effectiveness of these products.

Sources

  1. Carnitine: Fact Sheet for Health Professionals NIH Office of Dietary Supplements