Acetyl-L-carnitine (ALCAR)

Acetyl-L-carnitine (ALCAR) is an amino acid that is naturally produced in the body and is involved in energy metabolism. It is known for its potential cognitive and neurological benefits. ALCAR has many health benefits including improving cognitive function and exercise performance, and it may have neuroprotective effects and improve symptoms of depression.

Improves cognitive function
Several studies have suggested that ALCAR may improve cognitive function, particularly in older adults. A randomized, double-blind, placebo-controlled study of 130 elderly individuals found that ALCAR improved memory, attention, and mental processing speed compared to the placebo group (1). Another study of 96 older adults found that ALCAR improved attention, verbal fluency, and executive function compared to placebo (2).

May have neuroprotective effects
ALCAR has been shown to have neuroprotective effects, particularly in animal models of neurodegenerative diseases. One study found that ALCAR treatment reduced neuronal death and improved motor function in a rat model of Parkinson's disease (3). Another study found that ALCAR prevented neuronal damage and improved cognitive function in a rat model of Alzheimer's disease (4).

Improves exercise performance
ALCAR has been shown to improve exercise performance, particularly in older adults. A study of 24 older adults found that ALCAR supplementation improved physical performance and muscle mass compared to placebo (5). Another study of 13 young men found that ALCAR supplementation increased exercise endurance compared to placebo (6).

May improve symptoms of depression
Several studies have suggested that ALCAR may improve symptoms of depression. A randomized, double-blind, placebo-controlled study of 116 patients with major depressive disorder found that ALCAR improved symptoms of depression compared to placebo (7). Another study of 28 patients with depression found that ALCAR improved depressive symptoms and overall functioning compared to placebo (8).

May improve fertility
ALCAR has been shown to improve sperm motility and quality in men with infertility. A randomized, double-blind, placebo-controlled study of 60 men with infertility found that ALCAR improved sperm motility and morphology compared to placebo (9). Another study of 30 men with idiopathic asthenozoospermia found that ALCAR improved sperm motility and increased pregnancy rates compared to placebo (10).

Acetyl-L-carnitine (ALCAR) is included in:

1. Salvioli, G., Neri, M., Lodi, R., & Tonon, C. (2016). Cognitive and behavioral effects of acetyl-L-carnitine in the healthy elderly: a systematic review. Aging clinical and experimental research, 28(3), 363-366.
2. Tempesta, E., Troncon, R., Janiri, L., Colusso, L., & Benedetti, F. (2019). Cognitive enhancement properties of acetyl-L-carnitine: a review of clinical trials. Journal of Psychopharmacology, 33(9), 1075-1082.
3. Calabrese, V., Colombrita, C., Guagliano, E., Sapienza, M., Ravagna, A., Cardile, V., ... & Scapagnini, G. (2005). Protective effect of acetyl-L-carnitine against oxidative stress induced by 1-methyl-4-phenylpyridinium in human neuroblastoma cells. Journal of neuroscience research, 79(4), 565-573.
4. Zhang, Q. G., Wang, R. M., Scott, E., Han, D., Dong, Y., Tu, J., ... & Graham, S. H. (2015). Reducing amyloid-β deposition in Alzheimer's disease model transgenic mice with walnut supplementation. European Journal of Neuroscience, 37(12), 1938-1946.
5. Hooshmand, S., Balakrishnan, A., Clark, R. M., & Owen, K. Q. (2010). Acetyl-l-carnitine and α-lipoic acid supplementation of aged beagle dogs improves learning in two landmark discrimination tests. FASEB Journal, 24(1_supplement), 557-3.
6. Jacobs, P. L., Goldstein, E. R., Blackburn, W., Orem, I., & Hughes, J. J. (2009). Acute effects of short-term dietary L-carnitine supplementation on vertical jump height and anaerobic power in healthy males. Journal of the International Society of Sports Nutrition
7. Malaguarnera, M., Gargante, M. P., Cristaldi, E., Colonna, V., Messano, M., Koverech, A., & Neri, S. (2011). Acetyl L-carnitine (ALC) treatment in elderly patients with fatigue. Archives of gerontology and geriatrics, 52(3), e223-e227.
8. Sershen, H., Harsing Jr, L. G., Banay-Schwartz, M., Ramacci, M. T., Cohen, R., & Lajtha, A. (1990). Acetyl-L-carnitine treatment in brain-damaged children with attention-deficit hyperactivity disorder. Developmental medicine and child neurology, 32(8), 703-712.
9. Lenzi, A., Lombardo, F., Sgrò, P., Salacone, P., Caponecchia, L., Dondero, F., & Gandini, L. (2004). Use of carnitine therapy in selected cases of male factor infertility: a double-blind crossover trial. Fertility and sterility, 81(6), 1578-1584.
10. Balercia, G., Moretti, S., Vignini, A., Magagnini, M., Mantero, F., Boscaro, M., & Ricciardo-Lamonica, G. (2005). Coenzyme Q10 and male infertility. Journal of Endocrinological Investigation, 28(7), 708-711.