Cerebrolysin vs Semax

Cerebrolysin

Cerebrolysin is not a single peptide. It is a standardised enzymatic hydrolysate of purified porcine brain protein containing low-molecular-weight neuropeptides and free amino acids, so no single half-life or molecular weight applies. DOSING CONVENTION: it is supplied as a ready-made sterile solution at 215.2 mg of peptide concentrate per mL, in sealed ampoules of 1, 2, 5, 10 and 20 mL, and it is prescribed in mL, never in mcg. The figures in this entry are the mg equivalents of that solution converted to mcg for consistency with the rest of the dataset: 215,200 mcg = 1 mL, 430,400 mcg = 2 mL, 1,076,000 mcg = 5 mL. It is NOT reconstituted, so the vial sizes above are ampoule contents and the bacteriostatic water field does not apply. Route matters: 5 mL is the practical ceiling for a single intramuscular injection, and the larger doses used in trials (10-50 mL/day) are given as slow intravenous infusions in a clinical setting, not IM. It is approved in a number of European, Asian and CIS countries but is NOT FDA approved. Human evidence is more substantial than for the other compounds in this class - randomized trials and Cochrane reviews in acute ischaemic stroke, vascular dementia, Alzheimer disease and traumatic brain injury - but the results are mixed, the stroke reviews found no convincing benefit on death or dependency, and much of the trial base is manufacturer-sponsored. Courses are conventionally given 5 days a week for about 4 weeks rather than continuously.

Semax

A synthetic heptapeptide: the ACTH(4-7) fragment extended with a Pro-Gly-Pro tail that blocks rapid enzymatic breakdown. It has no ACTH-like hormonal activity. Semax is a registered medicine in Russia and is given intranasally as a 0.1% or 1% solution; it is NOT approved in the US or EU and Western trial data is essentially absent, so the human evidence base is Russian-language and mostly from a small number of groups. Route matters here: it is an intranasal drug, not an injectable, and the nose-to-brain path is the whole point of the formulation. Russian dosing convention for cognitive and asthenic indications is roughly 200-2000 mcg per day split across two or three administrations (a few drops or sprays per nostril); the per-dose range listed here reflects that split, not the daily total. Much higher doses (around 12 mg/day of the 1% solution) have been used in acute ischaemic stroke under hospital supervision and are outside the scope of self-directed use. Plasma half-life is measured in minutes, so no meaningful hourly figure is listed; reported CNS effects outlast plasma presence.