Cortexin vs Dihexa
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.
Cortexin
Polypeptide nootropic extracted from the cortex of cattle or pigs, containing a mixture of low-molecular-weight neuropeptides (≤10 kDa). Registered pharmaceutical in Russia and widely used in Eastern European clinical medicine for stroke recovery, traumatic brain injury, cognitive decline, epilepsy, and cerebrovascular disease. Decades of Russian clinical literature support neuroprotective and neurorestorative effects.
Full profileDihexa
Dihexa is a synthetic hexapeptide derived from angiotensin IV, developed at Washington State University. It is considered one of the most potent nootropic peptides known — in rodent models it outperforms BDNF itself for synaptogenesis and cognitive enhancement, acting through the hepatocyte growth factor (HGF) / c-Met receptor system. Unlike most nootropics, Dihexa is highly lipophilic and can be administered transdermally or orally.
Full profile| Cortexin | Dihexa | |
|---|---|---|
| Category | Nootropic & Cognitive | Nootropic & Cognitive |
| Also known as | cortexin polypeptide, cortexin-10, neuropeptide bioregulator, cortexin-5 | PNB-0408, N-hexanoic-Tyr-Ile-(6) aminohexanoic amide |
| Evidence | Research-stage | Preclinical only |
| Dosing range | 5mg–20mg mg, daily IM injection for 10-day courses | 10mg–20mg mg, Once daily (or every other day — long-lasting effects) |
| Administration | Intramuscular injection | Oral (capsule), Transdermal (cream/lotion — lipophilicity makes this effective), Subcutaneous injection (less common) |
| Key side effects | Injection site pain, Rare allergic reaction, Headache (transient), Mild dizziness | Potential for pro-proliferative effects — HGF/c-Met pathway promotes cell growth (theoretical cancer concern at high doses), Headache (uncommon), Mental fatigue if overdosed, Long half-life means effects accumulate — take every other day initially |
| Cited sources | 2 references | 2 references |
Key differences
- Evidence level differs: Cortexin is research-stage, while Dihexa is preclinical only.
- Administration: Cortexin — Intramuscular injection; Dihexa — Oral (capsule), Transdermal (cream/lotion — lipophilicity makes this effective), Subcutaneous injection (less common).
- Frequency: Cortexin is typically daily IM injection for 10-day courses; Dihexa is Once daily (or every other day — long-lasting effects).
How each works
Cortexin
Cortexin's multi-component neuropeptide mixture modulates neurotransmitter systems, improves cerebral blood flow, enhances neuroplasticity (BDNF upregulation), and exhibits antioxidant and anti-apoptotic activity in neuronal tissue. Russian stroke rehabilitation trials show improved neurological deficit scores and functional recovery with 10-day cortexin courses compared to standard care alone. The mechanism involves multiple parallel neuropeptide signaling pathways.
Dihexa
Dihexa (PNB-0408) was developed by Joseph Harding and colleagues at WSU as a metabolically stable angiotensin IV analog. It binds hepatocyte growth factor (HGF), potentiating its interaction with the c-Met receptor — a pathway critical for dendritic branching, synapse formation, and synaptic plasticity. In rodent Alzheimer's and scopolamine-impaired models, Dihexa restored cognitive performance at doses ~7 orders of magnitude lower than BDNF. It readily crosses the blood-brain barrier due to its lipophilicity, unlike BDNF itself.
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.