Peptide Comparison
N-Acetyl SelankvsSemax
Acetylated tuftsin analogue heptapeptide with enhanced stability and anxiolytic, nootropic, and immunomodulatory properties acting through GABAergic modulation and BDNF upregulation
A brain-boosting peptide that supercharges your cognitive function by ramping up BDNF—the protein your neurons need to grow, connect, and stay sharp—all delivered through a simple nasal spray.
At a Glance
Quick
comparison
Dose Range
N-Acetyl Selank
0.15–0.5 mg
Semax
200–900 mcg
Frequency
N-Acetyl Selank
Once daily
Semax
Once daily
Administration
N-Acetyl Selank
Intranasal spray
Semax
Intranasal spray
Cycle Length
N-Acetyl Selank
4-6 weeks
Semax
4-6 weeks
Onset Speed
N-Acetyl Selank
Rapid (hours to days)
Semax
Rapid (hours to days)
Evidence Level
N-Acetyl Selank
Limited human trials
Semax
Moderate human trials (Phase 1-2)
Efficacy
Benefit
ratings
Anxiety Relief
Brain Health
Stress Resilience
Cognitive Enhancement
Neuroprotection
Mental Energy
Technical Data
Compound
specifications
N-Acetyl Selank
Molecular Formula
C35H59N11O10
Molecular Weight
793.9 g/mol
Half-Life
Extended compared to native Selank (~7-10 min plasma half-life); exact half-life of N-Acetyl form not published but estimated 2-3x longer
Bioavailability
Enhanced intranasal and subcutaneous bioavailability compared to native Selank due to N-acetylation protecting against aminopeptidase degradation
CAS Number
Not assigned (N-Acetyl Selank); 129954-34-3 (parent Selank)
Semax
Molecular Formula
C37H51N9O10S
Molecular Weight
813.9 g/mol
Half-Life
Several minutes to hours (intranasal effects persist longer)
Bioavailability
High via intranasal route (directly reaches brain)
CAS Number
80714-61-0
Protocols
Dosing
tiers
N-Acetyl Selank
Semax
Applications
Best
suited for
N-Acetyl Selank
Anxiolytic support without the sedation, tolerance, or dependence associated with benzodiazepines
N-Acetyl Selank is particularly well-suited for individuals focused on anxiolytic support without the sedation, tolerance, or dependence associated with benzodiazepines. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Cognitive enhancement through BDNF-mediated neuroplasticity
N-Acetyl Selank is particularly well-suited for individuals focused on cognitive enhancement through bdnf-mediated neuroplasticity. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Stress resilience and emotional regulation in high-demand environments
N-Acetyl Selank is particularly well-suited for individuals focused on stress resilience and emotional regulation in high-demand environments. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Complementary nootropic in cognitive stacks targeting multiple neurotransmitter systems
N-Acetyl Selank is particularly well-suited for individuals focused on complementary nootropic in cognitive stacks targeting multiple neurotransmitter systems. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Semax
Students and Knowledge Workers
If your day revolves around learning, studying, or processing complex information, Semax can be a game-changer. It enhances memory consolidation and recall while improving your ability to focus for extended periods—perfect for exam prep or demanding projects.
Those Seeking Mental Clarity
Brain fog? Semax works by boosting BDNF—the protein that helps neurons communicate effectively. Users often report feeling like the 'mental static' clears away, leaving sharper, more efficient thinking in its place.
Neuroprotection Seekers
Beyond immediate cognitive benefits, Semax offers protective effects for your brain cells. It acts as an antioxidant (especially against copper toxicity) and supports neuronal health—valuable for anyone concerned about long-term brain wellness.
Recovery Support (Under Medical Supervision)
In Russia, Semax is approved for helping stroke patients and those with traumatic brain injuries recover cognitive function. While not FDA-approved for this use elsewhere, the research shows meaningful neuroprotective and neurorestorative properties.
Safety Profile
Side
effects
N-Acetyl Selank
Common
- Nasal irritation
- Transient headache
- Mild drowsiness or fatigue
- Vivid dreams
- Appetite changes
Uncommon
- Nasal congestion or epistaxis
Serious
- Allergic reaction
Semax
Common
- Nasal irritation
- Mild headache
- Increased alertness
Uncommon
- Temporary blood pressure increase
- Dizziness
Serious
- Allergic reaction
Research Status
Safety
& evidence
N-Acetyl Selank
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
N-Acetyl Selank demonstrates favorable safety in preclinical and clinical research with no serious adverse events at therapeutic doses. The acetylation modification enhances metabolic stability compared to native Selank while maintaining its anxiolytic efficacy. Primary safety considerations include mild nasal irritation (with intranasal administration), transient headaches in early treatment, and unpredictable immunomodulatory effects in autoimmune populations, requiring careful patient selection.
Contraindications
- xKnown hypersensitivity to Selank, tuftsin, or any component of the formulation
- xPregnancy and breastfeeding — insufficient safety data
- xActive autoimmune disorders — immunomodulatory effects may be unpredictable
- xConcurrent use of immunosuppressive therapy — potential for immune system interference
Semax
Evidence Level
Moderate human trials (Phase 1-2)
FDA Status
Research compound
Safety Overview
Semax has been used clinically in Russia for over 25 years with an excellent safety profile. It's approved there for treating stroke, cognitive impairment, and optic nerve diseases. Studies consistently show minimal side effects, mostly limited to mild nasal irritation when using the spray form. Unlike stimulants, Semax doesn't appear to cause tolerance, dependence, or withdrawal symptoms even with extended use.
Contraindications
- xPregnancy or planning to become pregnant
- xCurrently breastfeeding
- xHistory of seizures or epilepsy
- xKnown allergy to ACTH-related peptides
- xUncontrolled hypertension
Decision Guide
Which is
right for you?
Choose N-Acetyl Selank if...
- Anxiolytic support without the sedation, tolerance, or dependence associated with benzodiazepines
- Cognitive enhancement through BDNF-mediated neuroplasticity
- Stress resilience and emotional regulation in high-demand environments
- Complementary nootropic in cognitive stacks targeting multiple neurotransmitter systems
Choose Semax if...
- Cognitive enhancement
- Memory improvement
- Focus and concentration
- Neuroprotection