L-Carnitine
How to Use It
Most people do not need carnitine supplements. For therapeutic use, typical amounts are 1–3 grams per day.
It remains unclear whether the propionyl-L-carnitine form of carnitine used in congestive heart failure research has greater benefits than the L-carnitine form, since limited research in both animals and humans with the more common L-carnitine has also shown very promising effects.2
Where to Find It
Possible Deficiencies
Carnitine deficiencies are rare, even in strict vegetarians, because the body produces carnitine relatively easily.
Rare genetic diseases can cause a carnitine deficiency. Also, deficiencies are occasionally associated with other diseases, such as diabetes and cirrhosis.3, 4 Among people with diabetes, carnitine deficiency is more likely to be found in persons experiencing complications of diabetes (such as retinopathy, hyperlipidemia, or neuropathy), suggesting that carnitine deficiency may play a role in the development of these complications.5 A carnitine deficiency can also result from oxygen deprivation which can occur in some heart conditions. In Italy, L-carnitine is prescribed for heart failure, heart arrhythmias, angina, and lack of oxygen to the heart.6
Best Form to Take
Derivatives of L-carnitine, specifically propionyl-L-carnitine and acetyl-L-carnitine, are available in supplement form, and have been used in some studies. Propionyl-L-carnitine has been used in some studies as an alternative to L-carnitine; it reportedly has greater affinity for cardiac and skeletal muscle than L-carnitine. Although acetyl-L-carnitine can be a source of L-carnitine and shows benefits in its own right, the use of L-carnitine and acetyl-L-carnitine are not interchangeable. DL-carnitine, which is a mix of L-carnitine and its isomer, D-carnitine, is no longer used due to concerns about D-carnitine’s safety and its interference with the L-isomer.7
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.