Peptide Comparison
N-Acetyl Semax AmidatevsSelank
Doubly modified ACTH(4-7) analogue heptapeptide with potent nootropic, neuroprotective, and neurotrophic properties acting through BDNF/NGF upregulation and transcriptome-level modulation of inflammatory and neurotransmitter gene networks
A clever brain-boosting peptide derived from your immune system's natural tuftsin molecule—it calms anxiety and sharpens your mind without the drowsiness or addiction risks of traditional anti-anxiety medications.
At a Glance
Quick
comparison
Dose Range
N-Acetyl Semax Amidate
0.1–0.6 mg
Selank
250–500 mcg
Frequency
N-Acetyl Semax Amidate
Once daily
Selank
Once daily
Administration
N-Acetyl Semax Amidate
Intranasal spray
Selank
Intranasal
Cycle Length
N-Acetyl Semax Amidate
8-12 weeks
Selank
4-6 weeks
Onset Speed
N-Acetyl Semax Amidate
Rapid (hours to days)
Selank
Rapid (hours to days)
Evidence Level
N-Acetyl Semax Amidate
Moderate human trials (Phase 1-2)
Selank
Limited human trials
Efficacy
Benefit
ratings
Recovery
Growth
Cognitive
Anxiety Relief
Cognitive Enhancement
Immune Support
Technical Data
Compound
specifications
N-Acetyl Semax Amidate
Molecular Formula
C39H54N10O10S
Molecular Weight
855.0 g/mol
Half-Life
Extended compared to native Semax; parent Semax has a plasma half-life of minutes, but pharmacological effects persist for hours due to intracellular signaling cascade initiation. N-Acetyl Semax Amidate achieves significantly longer effective duration
Bioavailability
Enhanced intranasal and subcutaneous bioavailability compared to native Semax; dual terminal modifications prevent enzymatic degradation from both ends
CAS Number
Not assigned (N-Acetyl Semax Amidate); 80714-61-0 (parent Semax)
Selank
Molecular Formula
C33H57N11O9
Molecular Weight
751.9 g/mol
Half-Life
2-3 minutes (plasma); effects last hours due to downstream signaling
Bioavailability
High intranasal absorption; near 100% subcutaneous
CAS Number
129954-34-3
Protocols
Dosing
tiers
N-Acetyl Semax Amidate
Selank
Applications
Best
suited for
N-Acetyl Semax Amidate
Cognitive enhancement through BDNF and NGF-mediated neuroplasticity
N-Acetyl Semax Amidate is particularly well-suited for individuals focused on cognitive enhancement through bdnf and ngf-mediated neuroplasticity. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Neuroprotection during and after cerebral ischemic events or brain injury
N-Acetyl Semax Amidate is particularly well-suited for individuals focused on neuroprotection during and after cerebral ischemic events or brain injury. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Nootropic stacking for enhanced learning, memory, and cognitive processing speed
N-Acetyl Semax Amidate is particularly well-suited for individuals focused on nootropic stacking for enhanced learning, memory, and cognitive processing speed. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Attention and focus improvement for cognitively demanding tasks
N-Acetyl Semax Amidate is particularly well-suited for individuals focused on attention and focus improvement for cognitively demanding tasks. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Selank
Anxiety Without the Fog
If traditional anti-anxiety medications leave you feeling sedated, foggy, or 'not yourself,' Selank offers a refreshing alternative. It calms anxious thoughts while keeping your mind sharp—like turning down the volume on worry without muting your brain.
Cognitive Performers
Students, professionals, and anyone facing demanding mental tasks love Selank for its dual action. It simultaneously reduces performance anxiety while enhancing memory and focus—the best of both worlds when you need to think clearly under pressure.
Stress Resilience Seekers
Chronic stress wreaks havoc on your brain. Selank helps protect against stress-induced cognitive decline by supporting BDNF levels and modulating your stress response. Think of it as building a buffer between you and life's daily pressures.
Natural Approach Enthusiasts
Derived from tuftsin—a natural peptide your own immune system produces—Selank appeals to those seeking more 'natural' solutions. It works with your body's existing systems rather than overriding them like synthetic drugs.
Safety Profile
Side
effects
N-Acetyl Semax Amidate
Common
- Nasal irritation
- Headache
- Mental overstimulation or restlessness
- Sleep difficulty
- Appetite changes
Uncommon
- Hair darkening
Serious
- Allergic reaction
Selank
Common
- Nasal irritation
- Mild fatigue
- Mild headache
- Injection site redness
Uncommon
- Vivid dreams
- Dizziness
Serious
- Allergic reaction
Research Status
Safety
& evidence
N-Acetyl Semax Amidate
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
N-Acetyl Semax Amidate shows excellent safety tolerability in Russian clinical studies with no serious adverse events reported at therapeutic doses. The amidate modification significantly enhances CNS penetration and metabolic stability compared to parent Semax, reducing dosing frequency. Side effects are primarily mild nasal irritation, transient headaches during initiation, and rare increases in dopaminergic tone manifesting as restlessness or insomnia at high doses, easily managed through dose adjustment.
Contraindications
- xKnown hypersensitivity to Semax, ACTH fragments, or any formulation component
- xPregnancy and breastfeeding — insufficient safety data in these populations
- xActive seizure disorders — neurostimulatory effects may lower seizure threshold in susceptible individuals
- xAcute psychotic episodes — dopaminergic and neurostimulatory effects may exacerbate symptoms
Selank
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
Selank has demonstrated a favorable safety profile across multiple Russian clinical studies spanning over two decades. In human trials comparing Selank to traditional anxiolytics like phenazepam, Selank showed comparable anti-anxiety effects with significantly better tolerability and no sedation, dependence, or memory impairment. The peptide has been approved for clinical use in Russia since the 1990s for anxiety and neurasthenia.
Contraindications
- xPregnancy or planning to become pregnant
- xCurrently breastfeeding
- xKnown allergy to peptide components
- xChildren and adolescents
- xSevere psychiatric disorders requiring immediate intervention
Decision Guide
Which is
right for you?
Choose N-Acetyl Semax Amidate if...
- Cognitive enhancement through BDNF and NGF-mediated neuroplasticity
- Neuroprotection during and after cerebral ischemic events or brain injury
- Nootropic stacking for enhanced learning, memory, and cognitive processing speed
- Attention and focus improvement for cognitively demanding tasks
Choose Selank if...
- Anxiety relief without sedation
- Cognitive enhancement and focus
- Memory improvement
- Stress resilience