Peptide serums on TikTok: separating hype from human data

What did @kodi_dyel actually say?

The creator opened by referencing the fictional drug from the movie Limitless, then pivoted to a pitch for his own supplement company, Biomass Labs. He described nootropics as "brain steroids" and named three specific compounds he uses: dihexa, synapse (likely a branded product), and semax. He says he takes one "every single Monday" during 12-to-14-hour client check-in days, and teased that his company will soon sell these in nasal spray form.

This is an important setup to understand: the entire video is a sponsored promotion for his own brand. The framing of nootropics as near-magical cognitive enhancers, with the Limitless reference doing a lot of heavy lifting emotionally, is a classic soft sell. That does not mean every claim is wrong. It does mean the information comes with a financial conflict of interest that 103,000 viewers probably did not clock.

Does the science back this up?

Some of it, modestly. The compounds he mentions vary wildly in how much human evidence exists. Semax has the most credible research base, primarily from Russian clinical studies. Dihexa is the wildcard with serious questions attached. The general claim that nootropics feel different from caffeine is actually reasonable.

Semax is a synthetic heptapeptide originally developed in Russia. It has shown effects on BDNF expression and cognitive performance in small human trials, mostly in stroke and cognitive impairment populations (Kolomin et al., 2013, Molecular Biology). These are not healthy gym-goers. Extrapolating to performance optimization in a healthy 20-something is a leap the studies do not support.

Dihexa is a different story. It was developed by Washington State University researchers (McCoy et al., 2013, Journal of Pharmacology and Experimental Therapeutics) as an angiotensin-derived compound with potent hepatocyte growth factor activity. It showed striking results in aged rodent models of Alzheimer's disease. There are no published human clinical trials. Zero. Calling this a routine Monday stack ingredient is the most scientifically unsupported claim in the video.

What did they get wrong (or right)?

He got the subjective description mostly right and the safety framing badly wrong. The claim that nootropics produce clarity and confidence without a caffeine-like jitter is consistent with user reports and some mechanistic research on peptide-based cognitive agents. That part is fair.

What is wrong: presenting dihexa as a casual performance supplement. Dihexa's HGF pathway activity is not trivial. HGF signaling is involved in cell proliferation, and there are legitimate theoretical concerns about long-term use in healthy individuals, particularly around oncogenic risk. No researcher studying dihexa has cleared it for healthy human use. The creator saying "I would never do something that is not going to make me better" does not substitute for clinical safety data.

The Limitless framing is also misleading by design. That movie drug is fiction. Opening with it primes viewers to believe the compounds that follow exist on a continuum with that kind of cognitive supercharging. They do not. The effect sizes in actual nootropic research are modest at best.

What should you actually know?

Semax has the most legitimate research behind it, but that research was conducted in clinical populations with neurological conditions, not in healthy adults seeking cognitive optimization. Dihexa has compelling rodent data and no human safety profile. That combination should make anyone pause before sourcing it from a fitness influencer's supplement brand.

The nasal spray format he mentions at the end matters pharmacologically. Intranasal delivery can increase CNS bioavailability for certain peptides, but it also changes the risk profile. Without pharmacokinetic data in humans, dosing a nasal peptide spray based on a TikTok video is genuinely not a good idea.

Also worth noting: regulatory status on several of these compounds is unsettled. Semax and dihexa are not FDA-approved drugs. Their sale as supplements occupies a legal gray area that the FTC and FDA have increasingly scrutinized. Biomass Labs is the creator's own company. Viewers should weigh the recommendations accordingly.