Difference Between Acetyl L-carnitine and L-carnitine

Acetyl L-carnitine vs L-carnitine

Acetyl L carnitine and L carnitine are naturally available, important compounds in our bodies. We can obtain them from our diets, and L carnitine is converted to Acetyl L carnitine after ingestion. This conversion takes place inside mitochondria. Outside mitochondria acetyl L carnitine can be converted back to L carnitine. Because of their importance in treating diseases, these compounds are produced as drugs.

Acetyl L- carnitine

Acetyl L-carnitine is a quaternary ammonium compound. This is also shown as ALCAR. This is naturally produced in animals and plants. This can be absorbed from various food sources too. Usually red meat and some of the vegetables contain acetyl L carnitine. This is an acetylated compound of L- carnitine and has the following structure.


Acetyl L carnitine is produced inside the body during strenuous exercise. At this instance, L-carnitine and acetyl Co-A are combined to produce acetyl L carnitine inside mitochondria. This reaction is catalyzed by carnitine O-acetyltransferase enzyme. When acetyl L carnitine is transported outside the mitochondria, it breaks down into the two constitutes again.

Acetyl L carnitine helps the body to produce energy, because it acts as a fatty acid transporter to mitochondria. It is also very important for many body functions, muscle movement, brain and heart function, etc. Acetyl L carnitine has several benefits to man; therefore, it is given as a drug to fight diseases. It is used for a variety of mental disorders such as peripheral neuropathy, Alzheimer’s disease, Lyme disease, Parkinson’s disease, age related memory loss etc. It is also used for Down’s syndrome; treat cardiovascular diseases, fibromyalgia, and aging. Though there is a beneficial side to this drug, at high concentrations it can be harmful too. At high doses, it can cause for insomnia and stimulatory effects. Some people may experience gastrointestinal irritation when a large amount is ingested.


This is a compound which is naturally synthesized in the liver and kidneys from the amino acid lysine and methionine. Ascorbic acid is also essential for the synthesis process. It is a quaternary ammonium compound and has the following structure.


L carnitine structure

L-carnitine acts as a transporter of long chain acyl groups from fatty acids into the mitochondria matrix and helps with energy production. It has regulatory effects on acetyl-CoA, which is a crucial compound having a wide range of roles in multiple energy production pathways. L carnitine is an antioxidant, thereby has a protective effect too.


What is the difference between Acetyl L-carnitine and L-carnitine?

• Acetyl L carnitine is the acetylated compound of L- carnitine.

• L carnitine has a hydroxyl group, whereas acetyl L carnitine has an acetyl group instead of the hydroxyl group.

• In terms of bioavailability, acetyl L carnitine is superior to L carnitine.

• After ingestion, acetyl L carnitine has a lower blood concentration compared to L carnitine.

• Acetyl L carnitine hydrolyzed more in blood compared to L carnitine.

• Acetyl L carnitine absorbs efficiently into cells compared to L carnitine.