Research CompoundNasal / SubQ · Nootropic

N-Acetyl Semax

NA-Semax — Acetylated Semax Analog

Half-life
~30-60 min (estimated longer than standard Semax)
Route
Intranasal or SubQ
Typical dose
300–600 mcg/day
Reconstitutable
Yes

What is N-Acetyl Semax?

N-Acetyl Semax (NA-Semax) is a modified version of Semax with an N-acetyl group added to the N-terminus. This modification increases resistance to enzymatic degradation, extending the active half-life and potentially enhancing CNS penetration. NA-Semax is considered by many community users to have a longer duration of action and slightly different receptor binding profile than standard Semax.

NA-Semax retains Semax's mechanism — BDNF/NGF upregulation, dopaminergic and serotonergic modulation, and anti-inflammatory CNS activity — while the acetylation provides enhanced stability against aminopeptidases. The acetyl group also changes the peptide's interaction with the lipid bilayer, potentially improving neuronal membrane penetration and CNS bioavailability via the intranasal route.

Research Evidence

BronzeEnhanced Stability

The N-acetyl modification is chemically established to reduce aminopeptidase degradation. Community reports suggest longer and smoother effects compared to standard Semax, consistent with the stability hypothesis.

BronzeCognitive Enhancement

Community use reports are consistent with Semax but with longer duration. The base mechanism (BDNF upregulation) applies — controlled trial data specific to NA-Semax is not available.

Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary

Dosing Protocols

Intranasal dose
300–600 mcg/day
Same route and approximate dose as standard Semax. Duration of effect reported to be longer — some users find less frequent dosing sufficient.
vs Standard Semax
Potentially longer acting
The acetyl modification suggests longer half-life. Some community users prefer NA-Semax for its reportedly smoother, longer cognitive effect vs the more acute standard Semax.
Cycle
2–4 weeks on, 2 weeks off
Similar cycling protocol to standard Semax to prevent tolerance.

Reconstitution / Preparation

VialDiluentConcentrationDraw
5 mg5 ml1 mg/ml300mcg = 30 units
10 mg10 ml1 mg/ml300mcg = 30 units
Open Reconstitution Calculator →

Frequently Asked Questions

Is NA-Semax better than standard Semax?

Not definitively — they have the same core mechanism but different pharmacokinetics. NA-Semax is reported to have a longer and smoother effect due to greater enzymatic stability. Whether this translates to greater cognitive benefit is individual. Some users prefer the more acute effect of standard Semax; others prefer the longer duration of NA-Semax.

Can NA-Semax and NA-Selank be combined?

Yes. NA-Semax (activating, focus-enhancing) and NA-Selank (anxiolytic, calming) are frequently combined in the same protocol. The NA versions of both may have more compatible and longer-lasting effect profiles than the standard versions.

References

  1. [1]Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax, an analog of ACTH(4-7) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54-60.
Disclaimer: This profile is for informational and research purposes only. Not medical advice. Always consult a licensed healthcare provider before using any compound.

This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.

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