N-Acetyl Selank vs Selank
Acetylated tuftsin analogue heptapeptide with enhanced stability and anxiolytic, nootropic, and immunomodulatory properties acting through GABAergic modulation and BDNF upregulation
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 [1][4].
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
N-Acetyl Selank
300–900 mcg/day
Selank
900–2700 mcg/day
Frequency
N-Acetyl Selank
Once daily
Selank
3 times daily
Administration
N-Acetyl Selank
Intranasal spray
Selank
Intranasal
Cycle length
N-Acetyl Selank
4-6 weeks
Selank
14 days, repeatable after 1-3 weeks
Onset speed
N-Acetyl Selank
Rapid (hours to days)
Selank
Rapid (hours to days)
Evidence level
N-Acetyl Selank
Limited human trials
Selank
Limited human trials
Benefit ratings
Anxiety Relief
Brain Health
Stress Resilience
Cognitive Enhancement
Immune Support
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)
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
Dosing compared
N-Acetyl Selank
Intranasal
250-300 mcg/day
Divided 2-3 times daily · 1-2 weeks initial
Lower end of the intranasal range used in Russian anxiolytic research; intranasal is the optimal CNS-delivery route for Selank [1][6].
300-900 mcg/day
Divided 2-3 times daily (100-300 mcg per dose) · 2-4 weeks per course
Daily intranasal range documented in Russian GAD trials, with anxiolytic effects comparable to medazepam [6].
Up to 2700 mcg/day
Divided 2-3 times daily · 2-4 weeks per course
Upper intranasal dose reported in a generalized anxiety disorder cohort [6]; used short-course.
Selank
Intranasal
Registered label dose
900 mcg/day total (3 doses of 300 mcg)
2 drops in each nostril, 3 times daily · Registered label dose
The approved dose on the Russian registration (ЛРС-003338/09): 2 drops in each nostril, three times a day. At 75 mcg per drop that is 300 mcg per administration and 900 mcg across the day, taken as a 14-day course that can be repeated after 1-3 weeks [7]. Human evidence, registered label.
Highest dose studied
2,700 mcg/day total (3 doses of 900 mcg)
900 mcg (12 drops) 3 times daily · Highest dose studied
The top of the range the developing institute describes as optimal — single doses of 300-900 mcg, 900-2,700 mcg a day split across three administrations — and the dose used in the multicentre generalised-anxiety and neurasthenia trial, where 2,700 mcg/day was compared against medazepam 30 mg/day for 14 days [9]. Because the label caps a single administration at 2-3 drops per nostril, a 900 mcg dose is given as 2-3 drops per nostril with the rest 15 minutes later [7]. Human evidence, trial protocol.
Subcutaneous injection
Community suggestion — not a studied protocol
300-500 mcg per injection
Once daily · Community suggestion — not a studied protocol
Community-reported, not peer-reviewed. No human study has tested subcutaneous selank and the registered product is nasal drops only [7], so this range comes from community and clinical-practice reports rather than a trial — there is no published safety or effectiveness data behind it. Two things worth knowing before choosing the route. The nasal spray is absorbed almost completely, with 92.8% of the dose reaching the bloodstream within 30 seconds [7], so injecting is not a way to get more of the peptide in. And in mice, the injected and intranasal routes did not act the same: injection shifted GABA-receptor binding while the nasal route shifted NMDA-receptor binding instead, which the authors put down to how each route is absorbed and broken down [13]. That is animal work, and no one has checked whether the same split happens in people.
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 [6][13].
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 [7].
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 [16].
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.
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 [1].
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 [1][2].
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 [2]. 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 [4]. It works with your body's existing systems rather than overriding them like synthetic drugs.
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
Selank
Common
- Nasal irritation
- Mild fatigue
- Mild headache
- Injection site redness
Uncommon
- Vivid dreams
- Dizziness
Serious
- Allergic reaction
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. [11][13] 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
- Known hypersensitivity to Selank, tuftsin, or any component of the formulation
- Pregnancy and breastfeeding — insufficient safety data
- Active autoimmune disorders — immunomodulatory effects may be unpredictable
- Concurrent use of immunosuppressive therapy — potential for immune system interference
Selank
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
The safety record comes from small Russian trials, and the numbers are worth seeing. In the 62-person generalised-anxiety and neurasthenia trial, 30 people took selank at 2,700 mcg a day and 32 took medazepam 30 mg a day for 14 days; the two calmed anxiety about equally, and selank also reduced fatigue where the benzodiazepine did not [9]. A second trial of 60 people with phobic-anxiety and somatoform disorders compared it with phenazepam and reported a clear anxiolytic effect that lasted about a week after the last dose [3]. The registered label lists only two side effects — an unpleasant taste when the drops run from the nose into the throat, and allergic reactions in people sensitive to the ingredients — and records no cases of overdose, which it attributes to how fast the peptide breaks down [7]. Neither trial published a per-arm adverse-event rate, so there is no side-effect percentage to compare against placebo.
Contraindications
- Pregnancy or planning to become pregnant
- Currently breastfeeding
- Known allergy to peptide components
- Children and adolescents
- Severe psychiatric disorders requiring immediate intervention
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 Selank if...
- Anxiety relief without sedation
- Cognitive enhancement and focus
- Memory improvement
- Stress resilience