amino acid · for chronic fatigue
L-Carnitine
Carries fat into the part of the cell that burns it for energy.
Say that in clinical terms
Transports long-chain fatty acids into mitochondria for beta-oxidation. Enhances ATP production from fat metabolism.
How strong is the research?
2 papers read, 2 supporting.
Tested as: Acetyl-L-carnitine and propionyl-L-carnitine (studied together in a single open-label CFS trial; evidence grades C by the citing review)
Who was studied: The cited paper is from a liver journal. It does not support this.
The research we could find tested Acetyl-L-carnitine and propionyl-L-carnitine (studied together in a single open-label CFS trial; evidence grades C by the citing review). That is a different preparation, and a result for one form is not a result for another.
How much to take
daily
500–2000 mg
Acetyl-L-carnitine (ALCAR) may have superior CNS effects. Divide dose if taking >1000mg.
Before you take it
- No NIH ODS Tolerable Upper Intake Level (UL) has been established for L-carnitine; long-term safety data at doses above 2g/day are limited.
- GI adverse effects at doses ≥3g/day: nausea, vomiting, abdominal cramps, diarrhea, and fishy body odor; effects are dose-dependent and related to TMAO production.
- TMAO cardiovascular risk: L-carnitine is converted by gut microbiota to trimethylamine (TMA), then by hepatic flavin monooxygenases to trimethylamine-N-oxide (TMAO); elevated TMAO is associated with accelerated atherosclerosis in animal models and with increased major adverse cardiovascular event risk in humans with concurrently high TMAO levels (Koeth et al. 2013, Nature Medicine; acknowledged by NIH ODS fact sheet); omnivores produce substantially more TMAO from the same L-carnitine dose than vegans or vegetarians.
- Warfarin/oral anticoagulant interaction: a single case report documents INR elevation from stable range (1.99–2.94) to 4.65 after a patient with a mechanical aortic valve added L-carnitine to stable warfarin therapy; no RCT evidence confirms this interaction; INR monitoring is prudent if co-administering; evidence quality is case-report only.
- Pivalate-conjugated antibiotics (pivampicillin, pivmecillinam): chronic co-administration may deplete carnitine stores (NIH ODS); this is a carnitine-depletion interaction, not a chelation/timing interaction.
- Anticonvulsants (valproic acid, phenobarbital, phenytoin, carbamazepine): chronic use may reduce carnitine levels; supplemental carnitine may be indicated but should be discussed with prescriber (NIH ODS).
What we make of it
The citation is from a liver disease journal.
The detail
The identifier resolves to the Journal of Hepatology, which covers liver disease and does not publish on chronic fatigue in the general population.