Semax

B+

Pharmacology

Semax is a synthetic peptide drug that was developed in Russia. It is a heptapeptide, consisting of seven amino acids, and it is a modified version of a fragment of adrenocorticotropic hormone, also known as ACTH.

Semax is generally regarded as a neurogenesis inducing peptide, increasing the plasticity in the brain. It is thought to do this through multiple pathways such as BDNF enhancement [1][2] and also seretonin (not that significantly [3]) and dopamine modulation. Semax also exhibits pleiotropic effects on immune response, angiogenesis, and calcium regulation at the genomic level, which likely underlie its neuroprotective actions in focal ischemia.

Semax is thought to be a 'cleaner' cognitive enhancer than general peptide extracts such as cortexin or cerebrolysin as it is a singular peptide. Effects are normally thought to include spatial cognitive enhancement, learning enhancement, and long-term memory enhancement. It has also been found in studies to be neuroprotective and it is approved for the treatment of ischemic stroke and transient ischemic attacks in Russia. Some users also report a moderate antidepressant effect as well.

Semax is generally well-tolerated [1], with few reported side effects. It is approved for human use in Russia, and also as it is a peptide, it is generally less likely to have cytotoxic, hepatotoxic, or other toxic side effects compared to small molecules. The main issue with peptides however, it that most are unsuitable for oral consumption. Semax is normally administered intranasally or intravenously for maximum efficacy, which can be a bit less convenient. It also is less stable than something like a small molecule, so it is advised to refrigerate Semax to extend its lifespan.

There are also multiple forms of Semax. The original form of Semax is generally used less than modified versions as the modified versions have a better Pharmacokinetic profile.

One modification of Semax is adding a N-Acetyl group, making N-Acetyl Semax. N-Acetyl Semax, also known as NA-Semax, is a modified version of Semax with an acetyl group added to the N-terminus, which increases its stability and potency. For some people, NA-Semax and NA-Semax Amidate have somewhat different profiles in terms of their effects, so it may be best to test both.

N-Acetyl Semax Amidate is a further modified version of N-Acetyl Semax with an additional Amidate group, which enhances its lipophilicity and blood-brain barrier permeability.

Some versions of Semax also have an acetate group added to improve the pharmacokinetics further, however it seems not very necessary.

A derivative of Semax called Semax-OG also exists, however there is not much information on it. NA-Semax and NA-Semax Amidate are used the most as they are normally superior to the base peptide.

The average dose commonly used intranasally for Semax and Semax derivatives is 200 to 600 micrograms (mcg) daily. Higher doses can have potentially anxiogenic and antisocial effects, so most users stay within the mentioned dose range.