Peptide stacking on TikTok: what @ohmysebb is likely getting wrong

What did @ohmysebb actually say?

The creator claimed that semax and selank "work better in nasal spray form" than injections, then added that "melanotan" (likely MT-II or PT-141) is "pretty decent" as a nasal spray too. They capped it with a blanket rule: "injection is always better than nasal." That last line contradicts the first claim, which is worth untangling because the contradiction actually contains a real insight, even if the framing is sloppy.

It is also worth noting that the transcript appears to be auto-captioned and garbled in places. "My loan attention too" almost certainly refers to melanotan, a peptide with a well-documented nasal spray history. We will fact-check based on that reasonable interpretation.

Does the science back this up?

Partly, yes, but the reasoning matters. Semax and selank are neuropeptides originally developed in Russia. The nasal route is not just convenient for these two, it is the clinically studied delivery route. Peptides administered nasally can exploit the olfactory and trigeminal nerve pathways to reach the central nervous system more directly, bypassing some of the degradation that would occur in peripheral circulation.

Semax, a synthetic ACTH analogue, was studied intranasally in Russian clinical trials for cognitive and neuroprotective applications (Kolomin et al., 2013, Molecular Biology). Selank, an anxiolytic peptide analogue of tuftsin, was also developed and trialed specifically as a nasal formulation by the Institute of Molecular Genetics in Moscow. There is essentially no peer-reviewed injection data for these two compounds in humans. So calling nasal "better" here is a bit misleading. It is more accurate to say that nasal is the primary studied route, not that it outperforms a rigorously tested injectable version that does not really exist in the literature.

For melanotan peptides, nasal use has been documented anecdotally and in some small studies, though subcutaneous injection is the more pharmacokinetically characterized route (Dorr et al., 1996, Journal of Clinical Oncology).

What did they get wrong (or right)?

The creator got the broad strokes right on semax and selank. These peptides have been studied and used clinically as nasal sprays, and that is not an accident. Credit where it is due.

What they got wrong is the framing. Saying these peptides "work better" in nasal form implies there is a head-to-head comparison showing nasal outperforms injection. There is not. The more honest statement is that nasal delivery is the only properly studied route for semax and selank, so we do not actually know how injection would compare in a controlled setting.

The blanket rule that "injection is always better than nasal" is also an overstatement. Bioavailability is route-dependent and peptide-dependent. Nasally administered compounds that target the CNS via the olfactory pathway can achieve brain concentrations that peripheral injection does not reliably replicate for the same dose. "Always" is doing a lot of work in that sentence, and it is not supported by the evidence.

The melanotan mention is a reasonable addition, though the garbled transcript makes it hard to know exactly which compound was referenced.

What should you actually know?

If you are considering any peptide for nasal use, the route of administration is not a lifestyle preference. It is a pharmacokinetic variable that affects how much of the compound reaches its target tissue, how quickly, and through what metabolic pathways.

For semax and selank specifically, nasal delivery is supported by the actual clinical literature. These compounds were designed for intranasal use. That does not mean compounded nasal spray formulations available through telehealth platforms are equivalent in quality or concentration to what was studied. Formulation stability, preservative choice, and pH all affect peptide integrity in a nasal spray, which is why sourcing from a regulated compounding pharmacy matters.

For most other peptides, the creator's general point holds up directionally. Subcutaneous injection typically delivers more predictable systemic bioavailability than nasal administration for peptides that are not specifically designed for CNS-targeted nasal delivery. But "always" is not a word that belongs in pharmacology.

• Semax and selank were developed and studied as nasal formulations, not as injections.
• Nasal peptide delivery can access CNS pathways that injection does not directly target.
• No peer-reviewed human trials have compared injectable versus nasal semax or selank head-to-head.
• Melanotan peptides have some documented nasal use, but injection is the better-characterized route.