Peptide Comparison
DihexavsSelank
Angiotensin IV-derived oligopeptide that potentiates hepatocyte growth factor to drive synaptogenesis and cognitive enhancement with extraordinary potency
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
Dihexa
5–20 mg
Selank
250–500 mcg
Frequency
Dihexa
Once daily
Selank
Once daily
Administration
Dihexa
Oral (capsule/tablet)
Selank
Intranasal
Cycle Length
Dihexa
4-6 weeks
Selank
4-6 weeks
Onset Speed
Dihexa
Moderate (1-2 weeks)
Selank
Rapid (hours to days)
Evidence Level
Dihexa
Strong human trials (Phase 3 or FDA approved)
Selank
Limited human trials
Efficacy
Benefit
ratings
Cognitive
Healing & Recovery
Anti-Aging
Anxiety Relief
Cognitive Enhancement
Immune Support
Technical Data
Compound
specifications
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
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
Dihexa
Selank
Applications
Best
suited for
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.
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
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
Selank
Common
- Nasal irritation
- Mild fatigue
- Mild headache
- Injection site redness
Uncommon
- Vivid dreams
- Dizziness
Serious
- Allergic reaction
Research Status
Safety
& evidence
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
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 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
Choose Selank if...
- Anxiety relief without sedation
- Cognitive enhancement and focus
- Memory improvement
- Stress resilience