Selank vs. Semax: Which One Is Which?

If you have been looking into peptides for your brain, you have likely tripped over these two names. They sound like a pair of confusing twins from a spy novel, but they actually do different things.

Both are synthetic heptapeptides, which is just a fancy way of saying they are small chains of seven amino acids made in a lab. They were both developed in Russia and have been used there for years, though the rest of the world is still catching up.

What is Semax all about?

Semax is based on a fragment of something called ACTH (adrenocorticotropic hormone). While that sounds like a mouthful, the important part is that it avoids the hormonal side effects usually associated with the adrenal system.

• How it works: It turns up the volume on brain-derived neurotrophic factor (BDNF), which is a protein that helps brain cells grow and survive.
• The focus: It acts on your dopamine and serotonin systems—the chemicals that handle reward and mood—to protect your brain.
• The history: It has been used in Russia since the 1990s as a standard treatment for ischemic stroke, which is when blood flow to the brain is blocked.

How is Selank different?

Selank is a version of a natural substance called tuftsin. While Semax is often linked to recovery and protection, Selank is usually discussed in the context of balance.

• The chill factor: It works on the GABA-A receptor system. This is the same system that drugs like benzodiazepines (anti-anxiety meds) target, but Selank reportedly does it without making you sleepy or causing a physical need for the drug.
• Multi-tasking: It also helps stabilize your serotonin and dopamine receptors and boosts BDNF, just like Semax.
• Immune bonus: Interestingly, it has immunomodulatory effects, meaning it helps manage the immune system. The data shows it can even help the body fight off the flu.

What are the experts unsure about?

Scientists are still working on these—turns out the human body is complicated. Who knew?

Both peptides have a Grade B or B- rating for evidence. While they have over 25 years of clinical use in Russia, there is very little research from Western countries. We have some cool brain scans (fMRI) showing they work, but we are missing the massive, gold-standard studies usually required by groups like the FDA.

For Selank specifically, scientists are still debating how well the nasal spray version actually gets into your system. Neither of these are FDA-approved in the United States.

This is a great one to bring up with your doctor. You can find peptide-experienced physicians in our Find a Doctor directory.

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This content is sourced exclusively from TruthTides clinical reference data and does not constitute medical advice.