Athletes are familiar with L-carnitine as an amino acid that stimulates muscle cells’ burning of fatty acids and that boosts endurance performance. The same L-carnitine also works as a hair-growth enhancer in lotions, according to an article published six years ago by German dermatologists in the Journal of Dermatological Science. The Germans’ study was financed by Henkel, a cosmetics manufacturer.
Athletes are familiar with L-carnitine as an amino acid that stimulates muscle cells’ burning of fatty acids and that boosts endurance performance. The same L-carnitine also works as a hair-growth enhancer in lotions, according to an article published six years ago by German dermatologists in the Journal of Dermatological Science. The Germans’ study was financed by Henkel, a cosmetics manufacturer.
There are a myriad products in drugstores, vitamin shops and webstores of which the manufacturers claim that they prevent hair loss. But despite the enormous amounts of money the companies must earn from these products, there are no human studies that show that these products really work. The study that was published in 2007 in the Journal of Dermatological Science was in this respect exceptional – although it wasn’t strictly speaking a true study, but a Letter to the Editor.
The researchers have published the results of real studies on the effects of L-carnitine on hair growth, but these were in-vitro studies. [Exp Dermatol. 2007 Nov;16(11):936-45.]
In these the Germans showed – in test tubes – that L-carnitine extended the growth phase in hair follicles, stimulated the development of cells and inhibited the dying off of cells. According to the study published in the Journal of Dermatological Science, L-carnitine also works in real live humans. The researchers performed their experiment on 51 subjects, aged between 21 and 60, all of whom had mild to severe hair loss.
The researchers got half of their subjects to apply a solution that consisted of 2 percent L-carnitine-L-tartrate to the skin on their head twice a day. The other half used a placebo.
After six months the researchers noticed that, in the experimental group, the number of hairs per square centimetre of skin on the head had increased by 15 percent. There was no increase in the number of hairs in the placebo group.
Hair is produced in the hair follicles, in a process that involves a number of phases. The growth phase is referred to as the anagen phase, and the phase in which hair no longer grows is called the telogen phase. The researchers discovered that applying the fluid that contained L-carnitine L-tartrate caused a shift from the telogen to the anagen phase in the hair follicles.
The photo below gives an impression of the effect that L-carnitine had on the hair of one of the test subjects at least. A = before treatment; B = after six months.
“This small pilot study, evidently, requires repetition with a much larger n of volunteers and a prolonged observational period”, the researchers write.
No follow-up study has ever been published. Maybe the sponsor found it too expensive, or thought that people with hair loss buy shampoos anyway. Or maybe a study was done, but the results were disappointing…
