Peptide therapy TikTok claims: what the science actually supports

What did @jzhn actually say?

Refreshingly little, honestly. The creator used semax and selank nasally for two weeks and reported noticing "extremely extremely subtle" effects, directly pushing back on TikTok's habit of portraying these peptides as instant cognitive miracles. That's a more honest take than most peptide content on this platform.

The framing is personal and anecdotal, which is exactly what it should be labeled as. No wild recovery claims, no before-and-after performance metrics, no promises. The creator essentially said: I tried this thing, the hype is overblown, I feel basically the same. That is a valid consumer report. It is not clinical evidence, but it is also not misinformation. Worth noting: the transcript shows some pronunciation stumbling ("neutropic," "some ax," "so length"), which suggests familiarity with these compounds is still developing, but that doesn't change the substance of what was said.

Does the science back this up?

Partially, yes. The subdued effects @jzhn describes are actually consistent with what the limited human research suggests. Neither semax nor selank has been studied in large randomized controlled trials in healthy, cognitively normal adults, which is the population most TikTok users belong to.

Semax is a synthetic heptapeptide derived from ACTH(4-7). Russian clinical trials have examined it in stroke recovery and optic nerve disease contexts (Kaplan et al., 2011, CNS Drug Reviews), not in biohacking populations. Selank is an anxiolytic peptide studied primarily for generalized anxiety disorder in Russian clinical settings (Semenova et al., 2010, Bulletin of Experimental Biology and Medicine). The effects described in those studies, reduced anxiety and modest cognitive support, are not the dramatic "awakening" TikTok edits promise. They are incremental, context-dependent, and often indistinguishable from placebo in lower-stakes populations. So the creator noticing "not that much" is actually the scientifically plausible outcome.

What did they get wrong (or right)?

They got the skepticism right. The peptide influencer ecosystem routinely overclaims on semax and selank, and calling that out directly is doing real work. Give credit where it is due.

What is missing is any acknowledgment of what we genuinely do not know. These are unregulated research compounds in most Western markets. The FDA has not approved either for any indication in the United States. Intranasal administration of peptides raises legitimate questions about bioavailability and dosing consistency that the creator doesn't touch. Sourcing matters enormously here: purity, concentration, and sterility of peptides bought outside a regulated platform vary wildly, and that risk goes completely unmentioned. There is also no discussion of whether two weeks is even a meaningful trial window for peptides with proposed neurotropic mechanisms. That is not a knock on the creator specifically, but it is a gap in the content that viewers should recognize.

What should you actually know?

Semax and selank have a more credible research base than many peptides circulating on TikTok, but that bar is low and the studies are mostly small, old, and conducted in clinical populations. Healthy adults using them for "optimization" are operating largely outside the studied use case.

The nasal route is generally considered preferable for these peptides because both are rapidly degraded in the gut, but intranasal peptide absorption is inconsistent and poorly characterized outside controlled settings. Anyone sourcing these without a licensed provider has no real way to verify what they are actually administering. Two weeks is also a very short observation window. Some neurological and anxiolytic effects from compounds in this class take longer to become apparent, or may require a specific stress context to be detectable at all. The absence of a dramatic effect in a healthy young person is not proof the compounds do nothing, but it is also not proof they do anything either. That ambiguity is the honest place to land.

Should you try semax or selank based on this video?

That is a clinical question, not a TikTok question. The creator is admirably skeptical, but skepticism from an individual user is not a safety clearance. Both peptides interact with neurotrophic pathways, including BDNF signaling, and the long-term effects in healthy adults are simply not known. If you are interested in peptide therapy, the appropriate path is through a licensed provider who can evaluate your individual history, not a 60-second video.

• Semax's proposed mechanism involves BDNF upregulation and neuroprotection (Dolotov et al., 2006, Journal of Neurochemistry).
• Selank's anxiolytic effects are linked to modulation of the GABAergic system and enkephalin metabolism.
• Neither compound has FDA approval or a defined therapeutic index for healthy adult use.