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N-Acetyl Semax

Acetylated Semax variant with enhanced stability and penetration

N-Acetyl Semax molecular structure

Overview

N-Acetyl Semax is an acetylated variant of Semax with enhanced stability, improved blood-brain barrier penetration, and potentially stronger nootropic effects. The acetyl modification protects against enzymatic degradation and may increase potency compared to standard Semax. Like its parent compound derived from ACTH (4-10), N-Acetyl Semax increases brain-derived neurotrophic factor (BDNF) expression, enhances dopamine and serotonin neurotransmission, and provides neuroprotective effects. Research suggests the acetylated form may produce more pronounced cognitive enhancement, including improved memory, attention, and mental clarity. The peptide demonstrates antioxidant properties and may protect against hypoxic and ischemic brain injury. N-Acetyl Semax is administered intranasally for direct brain delivery. Studies indicate potential applications for cognitive enhancement, depression, anxiety, stroke recovery, and neurodegenerative conditions. The modification allows for potentially lower dosing while maintaining or enhancing efficacy. Clinical use is primarily documented in Russian medical literature.

Last reviewed: 2026-08-18

Identity & Aliases

Also known as

N-Acetyl SemaxAc-SEMAXAcetylated SemaxSemax (acetylated form)
CAS2920938-90-3
PubChem172638603

Full composition (formula, molecular weight, sequence) in Quick Facts →

Research Areas

Nootropics / cognitive enhancementNeuroprotection and stroke recoveryBDNF modulation

Available Evidence

Human

Semax (parent heptapeptide, ACTH 4-10 derivative) has been studied in Russian clinical literature, including a clinical/electrophysiological study in acute hemispheric ischemic stroke reporting improved recovery (PMID 11517472). Specific human trials of the N-acetyl variant are scarce and largely confined to Russian-language literature.

Animal

Animal studies of Semax and its acetylated analogs report increased brain-derived neurotrophic factor (BDNF) expression, neuroprotection in hypoxic/ischemic models, and cognitive-enhancing effects.

Uncertain

Most human data concern unmodified Semax rather than the acetylated form; the acetyl modification's added benefit over standard Semax is supported mainly by manufacturer/analog claims, and the compound is not FDA-approved.

Key Studies & Findings

2 studies
Preclinical2006

Semax, an ACTH(4-10) analog, upregulates BDNF and trkB expression in the rat hippocampus, providing a molecular basis for its cognitive/neuroprotective effects.

Benefits & Effects

4 documented

Enhanced cognitive effects

anecdotalCognitive

Improved stability vs Semax

anecdotalPharmacokinetics

BDNF upregulation

anecdotalCognitive

Neuroprotection

anecdotalCognitive

Side Effects & Safety

2 reported

Well-tolerated

MildRare Reversible

Nasal irritation

MildRare Reversible

Onset: immediate

Limitations & Open Questions

Peer-reviewed human evidence is dominated by older Russian studies of Semax itself; the N-acetyl variant lacks independent large trials, is not FDA-approved, and much circulating dosing/safety guidance is anecdotal or vendor-sourced.

Pharmacology

Heptapeptide derived from ACTH(4-10) with N-terminal acetylation intended to improve enzymatic stability and blood-brain barrier penetration; administered intranasally; reported to raise BDNF and modulate dopaminergic/serotonergic transmission. Research/limited-regional-medicine status.

Reported Research Dosing

Reported values from research literature and community protocols. Educational reference only — not a dosing recommendation or medical advice.

300-600 mcg 1-3x/day

Route: Intranasal
Half-life: Extended

Research Protocols

Cognitive enhancement

Dose
600μg
Frequency
1x daily
Route
Intranasal spray

Mental fatigue resistance

Dose
800μg
Frequency
1x daily
Route
Intranasal spray

Memory enhancement

Dose
600μg
Frequency
2x daily
Route
Intranasal spray

Neuroprotection

Dose
1200μg
Frequency
1x daily
Route
Intranasal spray

Research protocols are for educational purposes only. Always consult qualified medical professionals.

Frequently Asked Questions

Is N-acetyl Semax FDA approved?

No. It is not FDA-approved; the parent compound Semax has registered medical use in Russia, but the acetylated variant is primarily a research compound.

How does acetylation change Semax?

The N-terminal acetyl group is designed to protect against enzymatic degradation, extending stability and potentially potency versus unmodified Semax - though comparative human data are limited.

Research Citations

1
Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties.

Magrì A, Tabbì G, Giuffrida A, Pappalardo G, Satriano C, Naletova I, Nicoletti VG, Attanasio F (2016)

Related Resources

Quick Facts

Formula

C39H53N9O11S

Molecular Weight

855.0

Sequence

MEEEIAALVIDNGSGMCKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIEHGIVTNWDDMEKIWHHTFYNELRVAPEEHPVLLTEAPLNPKANREKMTQIMFETFNTPAMYVAIQAVLSLYASGRTTGIVMDSGDGVTHTVPIYEGYALPHAILRLDLAGRDLTDYLMKILTERGYSFTTTAEREIVRDIKEKLCYVALDFEQEMATAASSSSLEKSYELPDGQVITIGNERFRCPEALFQPSFLGMESCGIHETTFNSIMKCDVDIRKDLYANTVLSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWISKQEYDESGPSIVHRKCF

Mechanism

Enhanced version of Semax with improved bioavailability and stability

Safety Information

Research compound. Enhanced stability version of Semax. Not FDA approved.

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