L-Carnosine is a naturally occurring dipeptide of beta-alanine and L-histidine, concentrated in brain and muscle tissue. Its interest in neurology comes from doing several things at once: it scavenges copper and zinc, regulates NMDA and GABA receptors, modulates dopamine and glutamate levels, buffers oxidative stress, and supports neurotransmitter regulation and neuroprotection.
L-Sharp 400 delivers 400 mg of L-Carnosine per 5 ml. It is positioned as an effective adjuvant with a demonstrated mechanism of action — support alongside standard therapy in autism spectrum disorder, ADHD, epilepsy, OCD, cerebral palsy and learning disorders, and separately in depression, MDD, schizophrenia, Parkinson's disease, Alzheimer's disease and dementia.
The published data behind it is the reason it exists in this form. In the Handbook of Autism and Pervasive Developmental Disorder, L-Carnosine carries a Grade B recommendation — provisionally recommended — while several conventional agents in the same table are graded C with the note that adverse effects are common.