Selank vs. Semax on TikTok: What the science actually supports

What did @learnwithmoises actually say?

The creator walked through two research peptides, Semax and Selank, positioning them as distinct cognitive and anxiety tools. On Semax, they said it "creates influence in something called BDNF" and tied that to neuroplasticity, faster thinking, and brain recovery. On Selank, they said it "targets the GABA pathway" similarly to benzodiazepines but "without dissidation" (likely meaning dependency or sedation). The closing pitch: "One pushes performance. One soothes the nervous system, but together, they might make you feel unstoppable."

Worth noting: the creator repeatedly called Semax "C-max" throughout the video, which introduces confusion for viewers trying to research it. They also described Semax as "a fragment of ACTH" and Selank as "modeled after an immune peptide called Tuftsin." Those are the core scientific claims we need to examine.

Does the science back this up?

Partially, yes. The BDNF connection for Semax is real and reasonably well-documented in animal models. The Selank-GABA link exists in the literature too, though it is more nuanced than the video makes it sound. The problem is that most of this research is preclinical or comes from Russian clinical trials that have not been replicated in large Western peer-reviewed studies.

Semax is indeed a synthetic heptapeptide derived from the ACTH(4-10) fragment. Research by Dolotov et al. (2006, Journal of Neurochemistry) showed Semax increases BDNF and its receptor TrkB in rat brain tissue. A small Russian clinical study published in Molekulyarnaya Biologiya (Shadrina et al., 2010) found gene expression changes consistent with neuroprotective effects in stroke patients. These are not nothing, but they are also not the slam-dunk the video implies. Selank's GABA modulation has been described in Russian pharmacology literature, including work by Semenova et al. (2010, CNS Drug Reviews), which noted anxiolytic effects potentially linked to GABAergic and serotonergic pathways. The benzodiazepine comparison, however, is a stretch that needs context.

What did they get wrong (or right)?

They got the basic pharmacological origins right. Semax as an ACTH fragment and Selank as a Tuftsin analog are accurate. The BDNF claim for Semax is supported by animal data. These are genuine wins for the video's credibility on the foundational facts.

Where it gets sloppy: the creator said Selank targets "the same calming effects that you see are targeted from benzodiazepines." Benzodiazepines work by directly potentiating GABA-A receptor activity with strong binding affinity. Selank's proposed mechanism is far less defined and the strength of effect is not remotely comparable to a benzo. Presenting them as mechanistically parallel, even with the "without dependency" caveat, is misleading to anyone who has struggled with anxiety and might read this as an equivalent swap. It is not. The video also does not mention that neither peptide is FDA-approved, that quality control in peptide sourcing is a serious issue, or that human clinical data outside of Russia is extremely thin. Saying they "might make you feel unstoppable" is the kind of framing that belongs in a supplement ad, not a health education video.

What should you actually know?

Both peptides exist in a regulatory gray zone in the United States. Neither is FDA-approved for any indication. Semax is approved and used clinically in Russia for stroke and cognitive impairment. Selank has been studied as an anxiolytic in Russia, but that does not mean the research translates cleanly to other populations, doses, or delivery methods.

The intranasal route the caption mentions is consistent with how these peptides have been studied, since it bypasses some degradation issues and may improve CNS delivery. But "fast absorption" does not equal safety or predictable efficacy in a general population. Peptide purity from compounding or research chemical sources is an unresolved real-world problem. A 2021 analysis published in JAMA Internal Medicine (Cohen et al.) found significant labeling inaccuracies across peptide and research chemical products sold online. If you are considering either of these compounds, that conversation starts with a licensed clinician who understands your full health picture, not a 60-second TikTok.