Cerebrolysin

Cerebrolysin is manufactured by controlled enzymatic digestion of purified porcine brain proteins, yielding a mixture of peptides below roughly 10 kDa together with free amino acids. There is no single active constituent, and the product specification describes a process and a profile rather than a structure.

This makes it unlike everything else in this catalogue. A synthetic peptide can be characterised to a sequence; a biological digest is characterised to a batch, and batch-to-batch comparability is itself a research question.

• Neurotrophic signalling, with proposed activity resembling that of endogenous neurotrophic factors

• Ischaemic stroke, the largest clinical literature, including several meta-analyses that disagree with each other

• Traumatic brain injury and post-acute recovery

• Vascular dementia and Alzheimer's research

• Neuroplasticity measures in animal models

The recurring methodological criticism is attribution: a positive result in a mixture does not identify what produced it, and a negative one does not exonerate any constituent.

Semax and P021 pursue neurotrophic signalling with defined single molecules, which makes them the useful methodological contrast. Dihexa targets the same downstream biology through a specific receptor pathway.