Peptide Comparison
N-Acetyl SelankvsDihexa
Acetylated tuftsin analogue heptapeptide with enhanced stability and anxiolytic, nootropic, and immunomodulatory properties acting through GABAergic modulation and BDNF upregulation
Angiotensin IV-derived oligopeptide that potentiates hepatocyte growth factor to drive synaptogenesis and cognitive enhancement with extraordinary potency
At a Glance
Quick
comparison
Dose Range
N-Acetyl Selank
0.15–0.5 mg
Dihexa
5–20 mg
Frequency
N-Acetyl Selank
Once daily
Dihexa
Once daily
Administration
N-Acetyl Selank
Intranasal spray
Dihexa
Oral (capsule/tablet)
Cycle Length
N-Acetyl Selank
4-6 weeks
Dihexa
4-6 weeks
Onset Speed
N-Acetyl Selank
Rapid (hours to days)
Dihexa
Moderate (1-2 weeks)
Evidence Level
N-Acetyl Selank
Limited human trials
Dihexa
Strong human trials (Phase 3 or FDA approved)
Efficacy
Benefit
ratings
Anxiety Relief
Brain Health
Stress Resilience
Cognitive
Healing & Recovery
Anti-Aging
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)
Dihexa
Molecular Formula
C27H44N4O5
Molecular Weight
504.7 g/mol
Half-Life
~12 days (following IV administration in rats)
Bioavailability
Orally active and blood-brain barrier permeable — specific oral bioavailability percentage not published
CAS Number
1401708-83-5
Protocols
Dosing
tiers
N-Acetyl Selank
Dihexa
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.
Dihexa
Age-Related Cognitive Decline
Dihexa directly addresses the synaptic loss that underlies age-related cognitive decline by building new functional synaptic connections in the hippocampus. Animal studies demonstrate restored spatial learning in aged rats, making it a compelling candidate for combating memory loss associated with aging.
Neuroplasticity Enhancement
Unlike nootropics that work through neurotransmitter modulation, dihexa drives physical neuroplasticity — the formation of new dendritic spines and synapses. This makes it ideal for individuals looking to enhance their brain's capacity for learning and adaptation at a structural level.
Neurodegenerative Disease Research
Preclinical evidence in APP/PS1 Alzheimer's mice and scopolamine-induced amnesia models positions dihexa as a leading research compound for neurodegenerative disease. It is patented for potential use in Alzheimer's and Parkinson's diseases, with ongoing interest from the research community.
Advanced Nootropic Stacking
Dihexa's unique mechanism (HGF/c-Met potentiation) is complementary to most other nootropic mechanisms, making it an excellent addition to advanced cognitive enhancement protocols when combined with choline donors, racetams, or adaptogens.
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
Dihexa
Common
- Headache
- Vivid dreams or altered sleep patterns
- Emotional sensitivity
- Mild fatigue during adjustment
Uncommon
- Gastrointestinal discomfort
Serious
- Theoretical oncogenic risk from c-Met activation
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
Dihexa
Evidence Level
Strong human trials (Phase 3 or FDA approved)
FDA Status
Research compound
Safety Overview
Dihexa has demonstrated a favorable safety profile in published animal studies, with no reported tumorigenic effects or organ toxicity at cognitive-enhancing doses. However, the compound has not undergone formal human clinical trials, and long-term safety data does not exist. The primary theoretical safety concern is sustained activation of the HGF/c-Met proto-oncogenic pathway, which could theoretically promote tumor initiation or growth. The extremely long half-life (~12 days) raises additional concerns about compound accumulation with chronic daily dosing. Anecdotal reports from the nootropics community generally describe good tolerability at doses of 5-20 mg daily, with headaches and vivid dreams as the most commonly reported effects.
Contraindications
- xKnown or suspected malignancy — c-Met/HGF pathway activation may promote tumor growth
- xPregnancy and breastfeeding — no safety data available
- xHistory of cancer, particularly HGF/c-Met-driven tumors (hepatocellular, gastric, lung)
- xSevere hepatic impairment
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 Dihexa if...
- Cognitive enhancement and memory consolidation in age-related decline
- Supporting neuroplasticity and new synaptic connection formation
- Research into neurodegenerative disease therapeutics (Alzheimer's, Parkinson's)
- Nootropic stacking for individuals seeking enhanced learning capacity