Peptide nasal sprays — which absorb, which don’t

For you needle haters out there (I used to be one of them), not every peptide works in nasal form. Even if you see a vendor selling it, doesn't mean it works. In fact vendors put some of that product up there as honey pots because the margin is fantastic. Size, charge, proteases in the mucosa, and whether the target is the brain or the bloodstream decide if a spray is real or theater.

Semax and Selank were designed as nasal drugs in Russia. They are short peptides (~750–850 Da). Names that fall into the same bucket include: Semax, Selank, Adalank, Adamax, DSIP, among others. All of these belong in a bottle with an atomizer.

Rules of thumb

Under ~1 kDa + CNS target → nasal can be the better route, not a compromise.

Over ~3 kDa + you need blood levels → pin it.

Those “60–70% nasal bioavailability” charts floating around are mostly unsourced. Treat them as marketing until you see an actual PK paper.

Congestion, spray volume, and whether you swallow the runoff will swing results more than the label mg.

Making a nasal spray from a vial

I'm a huge fan of nasal sprays and make them all the time. We have instructions / how-to on the peptide pages. My go to right now is 50% BAC sodium chloride combined with 50% sterile saline. Check the supplies page for links to buy - it helps to support the site.

Works well in nasal form

Semax (~813 Da)

Selank (~751 Da)

N-acetyl Semax / N-acetyl Selank

Adamax (N-acetyl Semax amidate)

DSIP (~848 Da)

Pinealon (~389 Da)

Oxytocin (~1,007 Da) — systemic BA is low; CNS delivery is why it’s used nasally

KPV (tiny tripeptide; local/mucosal more than “systemic peptide”) // I still recommend this as subq

Maybe / inconsistent

PT-141 (~1,025 Da) — some effect nasally, SubQ is still more reliable

BPC-157 (~1,419 Da) — no good human nasal PK; don’t treat it like a pin

NAD+ (~663 Da) — small enough, dose/effect is a question mark vs IV

Kisspeptin-10 — possible on paper, not a standard nasal drug

5-Amino-1MQ — small molecule, but spray data is thin; oral is the usual route

Does not belong in a spray

Semaglutide / tirzepatide / retatrutide

CJC-1295 / Ipamorelin

TB-500 (~5 kDa)

MOTS-c / SS-31

Tesamorelin / other long GH-axis peptides

Most “weekly metabolic” peptides