Semax

Semax is a synthetic heptapeptide analog of adrenocorticotropic hormone (ACTH 4-10 fragment) designed to have increased stability and penetration into the central nervous system. The sequence is Met-Glu-His-Phe-Pro-Gly-Pro with N-terminal acetylation. Semax is studied in laboratory settings for its potential effects on neurotrophic factor expression, neurotransmitter modulation, neuroprotection, cognitive processes, and adaptation to stress or ischemic conditions. Manufactured in the USA, it has a purity of ≥99% as determined by HPLC and is available as lyophilized powder in packs of 5mg or 10mg vials. Semax is for in vitro and in vivo laboratory research use only, not for human consumption, therapeutic use, or any other non-research application.

Semax Mechanism of Action in Research Environment

In experimental models, Semax modulates various neurotransmitter systems. It raises brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) expression in the hippocampal and cortical neurons. It boosts dopamine and serotonin turnover in the striatum and frontal cortex, supports stress resilience by modulating enkephalin and dynorphin systems, induces tyrosine hydroxylase expression, and increases the density of dopamine D1/D2 receptors in specific brain regions. Likewise, Semax has shown anti-inflammatory effects through the suppression of IL-6 and TNF-α production in neuroinflammatory models, as well as protection against oxidative stress and excitotoxicity in neuronal cultures. These actions are investigated through research on neuroprotection, cognition, memory consolidation, and adaptation to stress or ischemic conditions.

Semax Peptide Sequence

Semax (N-terminal acetylation) is a linear acetylated heptapeptide: Ac-Met-Glu-His-Phe-Pro-Gly-Pro (Ac-MEHFPGP)

Molecular Formula

C₃₇H₅₁N₉O₁₀S

Molecular Weight

813.93 Da

CAS Number

80714-61-0 The sequence is based on ACTH 4–10 (Met-Glu-His-Phe-Arg-Trp-Gly) with proline substitutions and C-terminal extension for stability and CNS penetration.

Semax 10mg

More material per gram means you get more out of Semax 10mg for long or repeat runs. This vial size is more appropriate for multi-dose protocols, longer-duration behavioral or tissue testing sessions, and neurochemistry analyses requiring increased total amounts across multiple rounds and sample sizes. It offers more flexibility when scaling up from pilot work or when repeated dosing is needed over weeks or months. This 10mg size minimizes frequent reorders for ongoing projects and maintains ≥99% purity and lyophilized stability. In broader models or studies with multiple treatment groups, researchers select 10mg to test Semax for neuroprotective or cognition-related research purposes.

Potential Research-Based Benefits of Semax

1. Neuroprotective Effects in Ischemic Models

Focal cerebral ischemia in rats under Semax administration at 50–250 µg/kg i.p. led to dose-dependent reductions in infarct volume (30%–50%), improved neurological scores, and increased BDNF and NGF expression in peri-infarct brain areas. These effects correlated with decreased neuronal apoptotic index and increased angiogenesis in the penumbra zone.

2. Cognitive and Memory Enhancement

In learning and memory paradigms (Morris water maze, passive avoidance), Semax enhanced acquisition and retention, particularly under ischemic or toxic conditions. Doses between 100–300 µg/kg improved performance compared to controls in both young and aged rats, correlating with increased BDNF levels in the hippocampus and frontal cortex.

3. Stress and Anxiety-Related Behavior

In chronic stress models, Semax-treated animals exhibited normalized anxiety-like behavior in the elevated plus-maze and open-field test. It restored dopamine and serotonin levels in brain regions affected by immobilization stress and mitigated stress-induced immune suppression.

4. Neurochemical and Immunomodulatory Actions

Semax elevated dopamine and serotonin turnover in the striatum and frontal cortex, increased tyrosine hydroxylase activity, and altered D1/D2 receptor density. In glial cell cultures, it decreased proinflammatory cytokines (IL-6 and TNF-α) while supporting anti-inflammatory profiles.

5. In Vitro Neuroprotection

In primary neuronal cultures, Semax demonstrated protection against glutamate excitotoxicity and oxidative damage, maintained mitochondrial function, and limited caspase activation. Semax remains investigational. There are no large-scale human studies, and it is not approved for therapeutic use.

How To Handle Semax

Handling Tips

• Do not shake vigorously (gently swirl if needed)
• Use sterile technique during reconstitution
• Minimize time outside the refrigerator
• Discard if the solution becomes cloudy or discolored

Important Disclaimer

Semax is an experimental research peptide intended only for in vitro or in vivo laboratory studies. It has not been evaluated by the FDA, EMA, or any regulatory authority for therapeutic use. No claims are made regarding safety, efficacy, or benefits in humans. For laboratory research use only — not for human or veterinary consumption.

Referenced Citations

• Ashmarin IP, et al. (1997). Design and study of Selank and Semax as novel immunomodulatory peptides. Russian Journal of Bioorganic Chemistry.
• Medvedev VE, et al. (2007). Semax in the therapy of stroke patients. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova.
• Kaplan AY, et al. (1996). The effects of Semax on learning and memory in rats. Neuroscience and Behavioral Physiology.
• Dolotov OV, et al. (2006). Semax increases BDNF expression in the rat hippocampus. Neuroscience Letters.