What is L-carnitine?

L-Carnitine is an amino acid which supports metabolism, energy and increases endurance. It is commonly taken as part of a weight-loss programme as it helps the body turn fat into energy.

What is L-carnitine found in?

We can make L-Carnitine in our liver and kidneys through using two other amino acids lysine and methionine. From dietary sources, it is mainly found in meat[1].

What are the benefits of L-carnitine?

Energy production

It encourages energy metabolism by transporting long-chain fatty acids into the mitochondria to be used in the production of energy. Carnitine is concentrated in tissues like skeletal and cardiac muscle that metabolise fatty acids as an energy source[2]. This is why you would mainly find Carnitine in supplements designed for sports performance and to optimise energy levels.

Neuroprotective

It has recently been studied for its neuroprotective effects in disorders such as Alzheimers’s disease, traumatic brain injury and hypoxia-ischemia and had promising results. Additionally, it has shown to improve energy, decrease oxidative stress and prevent subsequent cell death in models of adults, neonatal and pediatric brain injury[3].

Fertility

Excitingly, L-Carnitine and its acetylated form, acetyl L-carnitine (ALC) have shown great promise in supporting women with infertility due to its capabilities to regulate the oxidative and metabolic status of the female reproductive system[4]. And the same goes for male infertility... A controlled study in china randomly assigned men who were infertile with low sperm acrosin activity to either an L-Carnitine and vitamin E group or a control group for 3 months. Compared with the baseline, the percentage of progressively motile sperm (PMS) was significantly increased in the L-Carnitine and vitamin E group after 3 months of treatment[5].

Ageing

Studies have also been conducted to see if L-Carnitine can help with aging eyes and the conditions associated with it. These indicate that carnitine is differentially distributed within the eye with the highest concentrations reported in the iris, ciliary body and the choroid-retina. In patients with age-related macular degeneration (AMD), acetyl-L-carnitine improved four parameters of visual function[6].

As you can see, the use of L-Carnitine in a clinical setting is varied and as with other amino acids, we recommend that it is ideally taken away from foods.