Dihexa (PNB-0408)
Synthetic peptidomimetic derived from angiotensin IV. Strong preclinical evidence for synaptogenesis (promoting new synapse formation) — described in animal studies as orders of magnitude more potent than BDNF in some assays. Of intense biohacking interest. NO human clinical trial data published.
Educational only — not medical advice. SmartPeptide does not prescribe, diagnose, or treat. Always consult a licensed healthcare provider before using any peptide, supplement, medication, or protocol.
What the research shows
Strong rodent and ex-vivo work demonstrating synaptogenic activity at very low doses. Mechanism involves c-Met receptor signaling. No published human clinical trials of any phase.
What's still experimental
All human use. Dose, route (oral vs. transdermal), duration, and safety are completely uncharacterized in humans.
Anecdotal / community reports
Nootropic communities use Dihexa for cognitive enhancement, post-injury recovery, neurodegenerative concerns. Self-experimentation logs vary widely and confound with other interventions.
Anecdotal reports are NOT scientific evidence. They reflect personal experience and may not generalize.
FDA approval status
Source: openFDA + DailyMed (NIH/NLM)Doses studied in research
Source: Published clinical trialWhat published trials tested or FDA-approved labels specify. Reporting research facts — not a SmartPeptide recommendation.
There are NO PUBLISHED HUMAN TRIALS for Dihexa. The numbers above are derived purely from rodent dosing scaled by community convention. Long-term effects of inducing synaptogenesis in adult humans are completely uncharacterized.
The doses below are aggregated from research-peptide community forums (Reddit, biohacker discussions). They are NOT supported by clinical trials, NOT FDA-approved, and NOT a SmartPeptide recommendation. Source purity, dose accuracy, and user-reported outcomes are unverifiable. We display this only because the information is publicly available elsewhere — visitors should absolutely consult a licensed clinician familiar with experimental peptides before any use.
Notes from the source: Dihexa is a peptidomimetic with strong rodent synaptogenic activity but ZERO published human trials of any phase.
How clinicians typically protocol this
Third-party reference · not our recommendationDosing phases, cycle lengths, and administration timing as listed in a compounding-pharmacy clinician reference guide. Shown so you can see what a real protocol looks like — and bring informed questions to a licensed clinician.
Dose numbers, frequencies, and cycle lengths in this panel are extracted from a clinician-facing reference protocol distributed by a US-based compounding pharmacy in November 2025. SmartPeptide has paraphrased all descriptive text and adds no endorsement. Always consult a licensed clinician.
Zero controlled human safety data. The mechanism (hepatocyte growth factor / c-Met agonism) has theoretical cancer risk. Reference values are community-reported, not trial-established.
Small-molecule angiotensin IV analog; studied preclinically for synaptogenesis. Essentially zero controlled human data.
Protocol phases
FDA enforcement & recalls
Live · openFDA Drug Enforcement APIMechanism & targets
ChEMBL · UniProt · Open TargetsMolecule (ChEMBL)
View on ChEMBLLive research
PubMed · ClinicalTrials.gov · Europe PMC · OpenAlexEurope PMC — 401,452 additional records
Includes EU/UK studies and PubMed Central full-text articles. Often surfaces research weeks before PubMed indexes it.
- Engineering nonconventional yeasts to produce carboxylic acids: Advances and ProspectsZhang L, Fan Y, Shi W, et al. · 2027Open access
- Metabolic state-driven monitoring and control of abnormal pigment formation in sodium gluconate fermentation by <i>Aspergillus niger</i>Sun J, Jiang Y, Jiang X, et al. · 2027Open access
- Identification of integration site library for the development of plasmid-free microbial cell factory in <i>Bacillus subtilis</i>Zong Z, Luo Y, Yuan WQ, et al. · 2027Open access
- Highly efficient production of <i>β</i>-caryophyllene in <i>Saccharomyces cerevisiae</i> using a novel synthase from <i>Artemisia argyi</i>Xiao X, Wan X, Lu H, et al. · 2027Open access
Research volume (OpenAlex topic graph)
Human clinical evidence
Semantic Scholar · AI TLDRs · influence-rankedHuman-study summaries for “dihexa OR PNB-0408 OR N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide” are available on Semantic Scholar but the shared free-tier API quota is exhausted right now. Try refreshing in a few minutes, or check the PubMed and Europe PMC panels above for the same literature.
Research funding & verification
NIH RePORTER · CrossRef DOI registryPublication landscape
CrossRef · DOI registry- National Natural Science Foundation of China1,505 works
- yok266 works
- Japan Society for the Promotion of Science261 works
- National Institutes of Health227 works
- Yok197 works
- National Science Foundation153 works
Funder diversity is a credibility signal. Research concentrated in a single drug company's funding warrants more scrutiny than research funded across NIH, charities, and academic grants.
Preprints — cutting edge
bioRxiv · medRxiv · via Europe PMCPreprints have NOT been peer-reviewed. They are early research shared by authors before formal validation. Treat findings as preliminary.
- PreprintSynchrotron Nano-FTIR Reveals Carbohydrate-Dependent Protein Conformational Changes at Bacterium–Nanoparticle InterfacesBispo Fidelis CL, Pereira AO, Rabelo RS, et al. · 2026-08-21
- PreprintSynthesis and Magnetic Properties of Novel 3d-4f Ln-Mn Hetero Nuclear ComplexesJiang F, Ke Y, Gao X, et al. · 2026-08-20
- PreprintCRISPR-based epigenome and genome editing reveal novel roles for PLEC in cartilage biology, mechanobiology, and response to inflammationSorial AK, Harissa Z, Steward N, et al. · 2026-08-18
- PreprintProgramming Energy–Bio Interfaces through Ligand-Directed Electronic Transport in Atomically Precise Gold NanoclustersSharma R, Dubey S, Mondal S, et al. · 2026-08-12
- PreprintGenome Mining of the Tumor Microbiome Reveals Biosynthetic Diversity and Potential Tumor-modulating MetabolitesPulliam C, Xu M, Holandez-Lopez K, et al. · 2026-08-09
- PreprintReal-time, macroscopic shortwave infrared Raman imaging for surgical and pre-clinical applicationsBruns O, Arús B, Yiu J, et al. · 2026-07-22
Known risks
Essentially unknown in humans. No Phase 1 safety data. Theoretical concerns about uncontrolled synapse formation. Source quality / purity is unverifiable.
Reported side effects
Unknown in humans. Anecdotal reports include headache, mild anxiety, sleep disruption.
FDA adverse event reports (FAERS)
Updated quarterly by FDAWhat requires medical supervision
Not approved. No clinician oversight available because there's no clinical trial infrastructure in humans.
Questions for your clinician
- Am I aware there are zero published human trials?
- What evidence-based cognitive interventions should we exhaust first?
- What would even constitute 'monitoring' for safety?