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2 min readLast reviewed 16 May 2026
Cognitive Enhancement

N-Acetyl Semax Amidate

Also known as: NA-Semax-Amidate · Ac-Semax-NH₂

A chemically protected analogue of Semax with N-terminal acetylation and C-terminal amidation, conferring substantially extended half-life and improved potency in research.

Cognitive EnhancementUK: Research onlyNot for human use
Category
Cognitive Enhancement
Half-life
Substantially extended relative to parent Semax
Formula
C₃₉H₅₄N₁₀O₁₀S

Section 1

Overview

N-Acetyl Semax Amidate is a chemically modified analogue of Semax in which the N-terminal methionine is acetylated and the C-terminal proline is amidated. These two terminal modifications protect the peptide from the aminopeptidase and carboxypeptidase enzymes that rapidly degrade the unmodified parent molecule, producing an analogue with substantially extended pharmacodynamic action.

Published comparisons report broadly similar pharmacological effects to Semax — BDNF and NGF induction, modulation of monoamine neurotransmission, neuroprotection in ischaemic models — but with longer duration of action per dose and, in some endpoints, greater potency.

It is positioned in laboratory research as a 'next-generation' Semax: same core pharmacology, extended action, less frequent dosing required to maintain effects.

Section 2

Discovery & History

  • Developed by the same Russian Academy of Sciences group responsible for the parent Semax compound, as a stability-optimised analogue.
  • Studied alongside Semax in published research from the mid-2000s onwards.
  • Not authorised as a medicine in any jurisdiction; remains a research chemical.

Section 3

Mechanism of Action

  • 1Identical mechanistic profile to parent Semax: BDNF/NGF induction, enkephalinase inhibition, monoaminergic modulation, neuroprotection.
  • 2Extended half-life through N-terminal acetylation and C-terminal amidation, which block the two principal proteolytic clearance pathways.
  • 3Greater bioavailability per administered dose and longer pharmacodynamic action.

Section 4

Researched Benefits

Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.

  1. 1Extended duration of action versus parent Semax — fewer doses required to maintain effects.
  2. 2Improved per-dose potency in some research endpoints.
  3. 3Same pro-cognitive and neuroprotective profile as Semax.
  4. 4Suitable for less frequent intranasal dosing in research protocols.

Section 5

Theoretical Dosing & Protocols

The protocols below summarise dose ranges reported in published research only. They are not recommendations and not a guide for human use.
RouteDosageFrequencyDuration
Intranasal (research)Microgram-range; specific protocols vary by studyOften once or twice daily versus 2–3× for Semax10 days to 8+ weeks in research

Note: Doses are not directly comparable to parent Semax due to potency differences.

Section 6

Administration Routes

  • Intranasal — primary research route.
  • Subcutaneous in some animal protocols.

Section 7

Safety Profile

Commonly reported

  • · Mild nasal irritation
  • · Occasional headache

Rare / theoretical

  • · Long-term safety data is limited; analogue-specific data is sparser than parent compound data

Contraindications

  • · Not authorised for human use
  • · Pregnancy/lactation — no data

Section 8

UK & EU Regulatory Context

United Kingdom

Not a licensed medicine in the UK. Research chemical only.

European Union

Not approved by the EMA.

Section 9

Clinical Studies Summary

Russian peptide pharmacology literature2012

Comparative pharmacokinetics of Semax and N-acetyl analogue

Direct comparison demonstrating significantly extended half-life and bioavailability for the acetylated/amidated analogue.

Peer-reviewed neuroscience literature2014

N-acetyl Semax effects on BDNF expression

Equivalent or greater BDNF/NGF induction at lower or equivalent doses versus parent Semax in rodent models.

Section 10

Frequently Asked Questions

The chief practical advantage is extended duration of action — fewer doses per day to maintain comparable pharmacodynamic effects, due to the analogue's resistance to the aminopeptidase and carboxypeptidase enzymes that rapidly clear unmodified Semax.

Section 11

Sourcing for Laboratory Research

Sourcing N-Acetyl Semax Amidate for laboratory research

Researchers in the United Kingdom and elsewhere typically obtain N-Acetyl Semax Amidate from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.

Reminder: research peptides are sold strictly for in vitro and preclinical laboratory purposes. Importation or supply for human consumption is not permitted under UK medicines legislation.

Further reading

Related research summaries

BDNF and the cognitive peptide family — the central mechanistic theme

BDNF induction is the common molecular endpoint shared by the most-studied nootropic peptides. What that means for research interpretation.

Read research summary

Intranasal peptide delivery — why the nose-to-brain route matters

The published case for intranasal administration as the dominant route in nootropic peptide research, and the limits of the nose-to-brain pathway.

Read research summary

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