Semax

Typical use cases

Dosing guidelines

Titration

Community/research reports often describe starting at a lower single daily dose and adjusting based on subjective response over days to weeks, since neuroplastic effects are said to build cumulatively. Educational information only, not medical advice.

Reconstitution

Lyophilized powder is typically dissolved in bacteriostatic or sterile water (sometimes saline) to make an intranasal solution, e.g., a 0.1% (1 mg/mL) drop/spray; concentration determines mcg per drop or spray. No reconstitution needed for pre-made nasal sprays.

Injection sites

Primarily intranasal (drops or spray into the nostrils); subcutaneous injection is also described in some research contexts

Storage & handling

Lyophilized powder stored refrigerated (2-8 C) or frozen for long-term; reconstituted solution kept refrigerated and used within a few weeks. Protect from light and heat.

Side effects

• Nasal irritation or dryness at administration site Mild · Common
• Headache Mild · Uncommon
• Overstimulation, restlessness, or irritability Mild · Uncommon
• Insomnia (especially with later-in-day dosing) Mild · Uncommon
• Fatigue or low mood (paradoxical, individual variation) Mild · Uncommon
• Allergic/hypersensitivity reaction Moderate · Rare

Research summary

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic analog of the ACTH(4-7) fragment to which a stabilizing Pro-Gly-Pro tail was added to slow enzymatic degradation. Most of the evidence base is preclinical: rodent studies consistently show that a single dose rapidly alters brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and TrkB-receptor gene expression in the hippocampus and frontal cortex, modulates serotonergic and dopaminergic systems, and influences immune and vascular gene programs in middle-cerebral-artery-occlusion stroke models. Its precise mechanism remains unclear; proposed actions include neurotrophin gene transcription, inhibition of enkephalin-degrading enzymes, and interaction with melanocortin receptors. In Russia and some neighboring countries Semax has been a registered prescription drug (nasal spray) since the 1990s for indications such as ischemic stroke, cognitive impairment, optic-nerve disease, and attention disorders, and it appears on Russia's list of vital and essential drugs. Human clinical data outside that region are limited, often small, and not subject to FDA or EMA review, so Western regulatory bodies have not approved it for any use. The parent peptide has a very short plasma half-life (roughly 2-5 minutes), but downstream neurotrophic and gene-expression effects are reported to persist far longer, which is why reported effects rather than plasma levels are said to guide dosing. Overall, mechanistic and animal evidence is substantial, but rigorous large-scale human trials are lacking.

Key references

• https://en.wikipedia.org/wiki/Semax
• https://pubmed.ncbi.nlm.nih.gov/16362768/
• https://pmc.ncbi.nlm.nih.gov/articles/PMC11498467/
• https://pubmed.ncbi.nlm.nih.gov/18756821/
• https://pmc.ncbi.nlm.nih.gov/articles/PMC3987924/

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