Cerebrolysin vs Semax
It is an injection promoted for stroke recovery, memory and brain injury. Trials point both ways, and the biggest review found no fewer deaths and more serious side effects. A nasal spray sold to sharpen memory and protect the brain after stroke. Studies from Russia look promising, but none was a proper blinded trial.
Both sit at grade B: some human evidence. Neither is FDA approved.
Evidence
BSome human evidence
BSome human evidence
Human studies cited
Animal or cell studies cited
Why the grade
For the stroke-recovery use there are randomized placebo-controlled trials, but they point in different directions. A Cochrane review pooled six RCTs with 1,501 participants and found no reduction in deaths and more non-fatal serious adverse events; the CARS trial (208 patients) and the two CAPTAIN trials in brain injury (185 patients pooled) reported modest functional benefits. Several trials were manufacturer-supported and had high risk of bias, so the grade stops at B.
Five Russian clinical studies cover stroke (30 patients versus 80 controls in 1997; 110 patients in 2018), chronic cerebrovascular insufficiency (187 patients), optic nerve disease and a 24-person imaging study in healthy volunteers. Several had control groups but none describes randomization and blinding in the way a modern trial would, and none has been replicated outside Russia. Controlled human studies exist, so B, but at the weak end.
FDA
Not approved
Cerebrolysin is not approved by the FDA for any use. It is a licensed medicine in more than 50 other countries, mainly in Eastern Europe, Russia and Asia, for stroke, dementia and brain injury.
Not approved
Semax is not approved by the FDA for any use and is sold in the United States as a research chemical. It is registered as a prescription drug in Russia. In July 2026 the FDA's Pharmacy Compounding Advisory Committee voted to recommend adding semax to the list of substances pharmacies may compound, against the advice of FDA staff. On 28 October 2026 HHS issued an enforcement discretion policy covering semax as a nasal product only, compounded by licensed pharmacies and physicians for named patients under sourcing, testing, labeling and reporting conditions. That is not an approval.
Sold for
Cerebrolysin is promoted in nootropic and longevity circles as a brain-repair injection that speeds stroke recovery, sharpens cognition and treats dementia.
Semax is sold as a nasal nootropic that sharpens memory and attention and protects the brain after stroke.
Studies say
Randomized trials exist, which earns a B, but the largest independent synthesis found no effect on death or dependence after stroke and a rise in serious adverse events, while smaller manufacturer-backed trials found small functional gains.
Russian clinical studies report faster recovery after stroke and fewer vascular events in chronic cerebrovascular disease, and a small imaging study shows it changes brain network activity in healthy people, but no blinded placebo-controlled trial has been published, so the cognitive claims are unproven.
Class
Neuropeptide preparation (porcine brain)
Nootropic peptide (ACTH(4-10) analog)
Route
Intravenous
Nasal