Acetyl-L-carnitine is an ester of the amino acid L-carnitine, which can be synthesized by the body from lysine and methionine. Acetyl-L-carnitine itself is formed by a transferase enzyme in the liver, the kidneys and the brain of humans. Regarding the biologic effects,
acetyl-L-carnitine increases the uptake of acetyl-CoA in the mitochondria – the «power plants» of the cell – by way of fatty acid oxidation. In addition, the production of acetylcholine is stimulated and the synthesis of proteins and elements of the cell membrane supported.
Due to these basal biochemical effects, L‑carnitine and its ester act more or less as a fuel for the energy provision in the cells. A deficiency in these important substances can therefore be felt in all body cells, and tissue subjected to great stress (muscles, myocardium, brain, etc.) is, in principle, much more prone to disturbances because it has a higher energy requirement.
In its natural occurrence, acetyl-L-carnitine is mainly found in the brain, but also in other tissues. The substance is, moreover, available as a food supplement. Although, in the strict sense, no states of deficiency with regard to acetyl-L-carnitine should exist as the body itself synthesizes the ester, the levels of acetyl-L-carnitine in tissue go down with aging. According to medical studies, the amino acid can be used successfully for various forms of dementia
(e. g. Alzheimer’s disease), age-related depression, HIV infections, diabetic neuropathy, cerebral circulatory disturbances as well as alcohol-induced cognitive deficits.
The exact modes of action of acetyl-L-carnitine are not yet fully elucidated. According to recent studies the ester acts as a parasympathomimetic due to its structural mutualities with acetylcholine. In this sense, acetyl-L-carnitine acts as a cholinergic neurotransmitter and as such seems to stimulate the neuronal metabolism in the mitochondria.
Groups of researchers attributed this cholinergic effects of acetyl-L-carnitine to a blocking of postsynaptic inhibition potentials. Other authors found that these effects are caused by a direct stimulation of the synapses. Of much greater importance, however, seems to be the fact that acetyl-L-carnitine can stabilize the fluidity of the cell membrane by regulating the endogenous sphingomyelin levels, which is probably due to an increased cellular energy metabolism in the mitochondria.
In addition, acetyl-L-carnitine also acts as a substrate reservoir for the cellular energy production. This could be decisive for the fact that sufficient intracellular levels of
acetyl-L-carnitine can prevent the excessive dying of nerve cells. It could also be proven that
acetyl-L-carnitine seems to enhance the effectiveness of certain nerval growth factors in individual brain areas.
As a whole, the substitution of acetyl-L-carnitine has proven to be positive in the diseases and conditions listed below:
Alzheimer dementia: numerous clinical studies confirmed that acetyl-L-carnitine has a positive effect on the cognitive performance in patients suffering from an Alzheimer-type dementia. Although long-term results are not available as yet, the intake of the substance for a longer period of time seems to improve the long-term memory.
Depression: in patients with major depression, acetyl-L-carnitine supplementation can lead to a changed circadian rhythm of the glucocorticoid secretion and an increase of the overall cortisol level. The additional administration of acetyl-L-carnitine can therefore support the treatment of depression symptoms.
Cerebral circulatory disturbances: there are positive results with regard to the use of acetyl-L-carnitine in cases of cerebral ischaemia as well as reperfusion. Studies have shown that the administration of acetyl-L-carnitine could reduce the neurologic secondary injuries experienced after such events.
Cardiovascular disturbances: like L-carnitine, acetyl-L-carnitine increases the transport of fatty acids for ATP production into the mitochondria of skeletal muscles and the myocardium and thus has a protective effect against damage caused by free radicals.
Diabetic secondary injuries: in diabetics, intravenous supplementation of
acetyl-L-carnitine alleviated neuropathic pain and improved the peripheral nerve function. The substance therefore seems to have positive effects on the metabolic as well as the functional disturbances in diabetic polyneuropathy.
Alcohol abuse: several studies have shown that both L-carnitine and
acetyl-L-carnitine have effects on the hepatic alcohol degradation but that the ester seems to delay alcohol oxidation much longer. Therefore, acetyl-L-carnitine could be of potential use in the therapy of cognitive disturbances in alcoholic disease.
One capsule contains 500 mg acetyl-L-carnitine in pharmaceutical grade.
Other ingredients: maltodextrin, magnesium stearate, SiO2.
In normal cases take 1 – 2 capsules 3 times a day at mealtimes with plenty of fluid.
The supplementing intake of acetyl-L-carnitine is effective and safe if it is within the recommended dosage range. Also in case of long-term application of over one year no essential side effects could be observed. The most frequently described undesired reactions were increased drive, nausea as well as vomiting. Pregnant or lactating women or persons who are under constant medical care should consult a doctor before use. Acetyl-L-carnitine is not suited for dialysis patients.
Generally a specialist should be consulted before taking food supplements. This is especially true in cases of chronic disease and regular intake of medication. If you experience symptoms while taking acetyl-L-carnitine you should consult a doctor and inform the doctor of the intake. Store in a cool, dry place and keep out of reach of children.