Cerebrolysin vs Semax
A neutral, side-by-side comparison of two nootropic & cognitive peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Cerebrolysin
Cerebrolysin is a brain-derived peptide mixture produced by controlled enzymatic breakdown of porcine brain proteins. Unlike synthetic peptides, it is a complex of ~25% low-molecular-weight neuropeptides and ~75% free amino acids, with the bioactive peptide fraction mimicking the endogenous neurotrophic factors BDNF, NGF, GDNF, and CNTF in their mechanisms. It has a 30+ year clinical history in Eastern Europe and Asia for stroke recovery, traumatic brain injury, Alzheimer's disease, and vascular dementia — with a substantial human trial database.
Full profileSemax
Semax is a synthetic heptapeptide derived from adrenocorticotropic hormone (ACTH) — specifically the 4–7 fragment modified with a C-terminal Pro-Gly-Pro extension for stability. Developed in Russia in the 1980s and used clinically there for stroke recovery, cognitive enhancement, and neuroprotection, it is one of the most researched nootropic peptides with a decades-long safety record in Eastern European clinical practice. Its primary mechanism involves potent upregulation of BDNF (Brain-Derived Neurotrophic Factor).
Full profile| Cerebrolysin | Semax | |
|---|---|---|
| Category | Nootropic & Cognitive | Nootropic & Cognitive |
| Also known as | FPF 1070, EBEWE Cerebrolysin, Brain-derived peptide mixture | ACTH(4-7)PGP, Met-Glu-His-Phe-Pro-Gly-Pro |
| Evidence | Research-stage | Investigational (in trials) |
| Dosing range | 5mL–30mL mL, Daily for 10–20 day courses (IV preferred in clinical use); SQ/IM for research access | 200mcg–900mcg mcg, Once or twice daily (intranasal most common) |
| Administration | Intravenous infusion (clinical standard — dilute in 100mL saline over 15–30 min), Intramuscular injection (research use — lower bioavailability), Subcutaneous injection (less common) | Intranasal (preferred — high CNS bioavailability), Subcutaneous injection |
| Key side effects | Injection site pain (IM route), Hyperthermia / fever (rare, higher doses), Agitation or anxiety (uncommon), Nausea | Mild anxiety or restlessness at high doses, Nasal irritation (intranasal route), Increased energy / difficulty sleeping if dosed too late in the day, Mild appetite suppression |
| Cited sources | 3 references | 3 references |
Key differences
- Evidence level differs: Cerebrolysin is research-stage, while Semax is investigational (in trials).
- Administration: Cerebrolysin — Intravenous infusion (clinical standard — dilute in 100mL saline over 15–30 min), Intramuscular injection (research use — lower bioavailability), Subcutaneous injection (less common); Semax — Intranasal (preferred — high CNS bioavailability), Subcutaneous injection.
- Dosing units differ: Cerebrolysin is dosed in mL, Semax in mcg — they operate at different scales.
- Frequency: Cerebrolysin is typically Daily for 10–20 day courses (IV preferred in clinical use); SQ/IM for research access; Semax is Once or twice daily (intranasal most common).
How each works
Cerebrolysin
Cerebrolysin's neuroprotective effects have been demonstrated in over 100 clinical trials, though most are from Eastern European and Asian centers with varying methodological quality. The CACTUS trial (N=256, multicenter) showed significant improvement in cognitive outcomes after ischemic stroke vs placebo. The ARTIST trials evaluated Cerebrolysin for Alzheimer's disease with mixed results. Meta-analyses of stroke and dementia trials generally support modest-to-moderate benefit. Mechanistically, the peptide fraction upregulates BDNF/NGF signaling, reduces excitotoxicity, inhibits caspase-3, and promotes synaptogenesis in animal and in vitro models.
Semax
Semax increases BDNF expression in the hippocampus and frontal cortex by 1.3–1.6x at research doses in rodent models. It also upregulates NGF (nerve growth factor) and modulates serotonin, dopamine, and NMDA receptor systems. Russian clinical data (not yet replicated in Western trials) suggests efficacy in ischemic stroke recovery, ADHD, glaucoma, and cognitive decline. The Pro-Gly-Pro C-terminal extension dramatically improves resistance to enzymatic degradation compared to native ACTH(4-7).
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.