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DiAnimal studies only

Dihexa

Dihexa is a lab-made peptide based on angiotensin IV. It has been tested for memory in rodents only. No human study exists.

Not approved anywhereKey 2014 mechanism paper retracted in April 2025Animal studies only
OverviewDosingMixingResearchCommunitySafetyFAQSources

Dihexa quick reference

TypeAngiotensin IV analog (modified peptide)
Studied forMemory in rodents
EvidenceRodents only; key paper retracted
RouteBy mouth in rodents; community oral or injection
Half-lifeNot established

What is Dihexa?

Lab-made angiotensin IV analog, built to cross into the brain.

Used by some for memory and focus.

Rodent-only; a main mechanism paper was retracted in 2025.

How Dihexa works

Angiotensin IV analog

Designed to resist breakdown and cross the gut and brain barriers.

HGF/c-Met idea

Proposed to boost HGF signaling. The 2014 paper behind this was retracted.

PI3K/AKT (mice)

In Alzheimer's-model mice it switched on PI3K/AKT and lowered inflammation markers.

Open question

The true target is unconfirmed. I found no cancer-risk study.

What Dihexa is studied for

AnimalsAlzheimer's model

APP/PS1 mice did better in a water maze after Dihexa (2021).

AnimalsBrain inflammation

Mice showed fewer inflammatory markers and less glial activation (2021).

AnimalsHuntington-like model

Rats on a toxin were not protected by PNB-0408, another name for Dihexa (2024).

AnimalsNerve repair

Rats with stem cells plus Dihexa walked better at 8–16 weeks (2021).

AnimalsScopolamine memory loss

2013 rat study reversed maze deficits; the journal later flagged concerns.

Dihexa dosing protocol

ItemWhat the sources show
Human doseNot established
Studied inRats and mice (given by mouth)

Oral dosing in rodents is described in the 2021 Alzheimer's mouse study. The 2014 Benoist paper was retracted in April 2025 and is not relied on here. ClinicalTrials.gov lists no Dihexa trial (searched 5 Nov 2026).

HUMAN DOSENone existsTrial
COMMUNITY RANGE5–30 mg daily by mouthCommunity

Label and trial amounts come from the sources below. Community amounts are what people report; they have not been tested.

Mixing

Community uses capsules or liquid by mouth. No human formulation exists.

Open the peptide calculator

What the research found

No human results exist. Animal evidence only:

0Human trials found
MiceDihexa restored water-maze learning in Alzheimer's-model mice (2021)
Rats (2024)A Huntington-like rat model was not helped by Dihexa (PNB-0408)

Brain Sci 2021 (PMID 34827486); J Huntingtons Dis 2024 (PMID 38489193). The 2014 JPET paper (PMID 25187433) was retracted in 2025 (PMID 40312093).

Dihexa community experience

What users report. Not tested in trials.

Positive reports

  • Mental clarity Some report clearer thinking and easier complex tasks.
  • Recall A smaller group notes better memory of new material.
  • Presence A few feel more mentally present.

Negative & mixed

  • No effect A large share notice nothing.
  • Overstimulation Headache or anxiety, mostly at higher doses.
  • Brain fog A few feel duller, not sharper.
  • Retraction worry Users keep raising the retracted paper and cancer-pathway fears.

Dihexa stacking

Dihexa + Semax

Different proposed pathways. Never studied together.

Dihexa + Selank

Thinking plus calm in theory. No interaction data.

Dihexa side effects & safety

Common

  • No human safety data exists.
  • Mild headache early on (community).
  • Anxiety or overstimulation (community).
  • Vivid dreams or disrupted sleep (community).

Less common

  • Brain fog or dulling (community).
  • Mood changes or irritability (community).
  • Stomach upset with oral use (community).
  • Cancer risk untested; HGF/c-Met signaling is linked to tumor growth.

Precautions

  • Avoid with cancer, past cancer or unexplained lumps.
  • Avoid in pregnancy and breastfeeding; no data.
  • Higher doses and long cycles: safety unknown.
  • Other growth-factor-affecting compounds: untested together.

Our verdict on Dihexa

Rodent-only evidence, a retracted key mechanism paper and one failed rat model. No human data exists.

Dihexa FAQ

Is Dihexa safe?

No human safety data exists. Cancer-risk studies are missing.

Why does Dihexa have a retracted paper?

The 2014 HGF/c-Met paper was retracted in April 2025. I did not check the reason.

Does Dihexa work in people?

No human study exists.

Is Dihexa taken by mouth?

Rodents got it by mouth. No human form or dose exists.

Sources

  • Benoist CC et al. J Pharmacol Exp Ther 2014, PMID 25187433 (RETRACTED April 2025; cited only to flag the retraction)
  • AngIV-analog Dihexa in APP/PS1 mice. Brain Sci 2021, PMID 34827486
  • ClinicalTrials.gov search by intervention name, run 5 Nov 2026: 0 results
  • Retraction notice, Benoist 2014 (JPET 351:390-402), April 2025, PMID 40312093; notice of concern 2021, PMID 34551987
  • McCoy AT et al. J Pharmacol Exp Ther 2013 (design paper), PMID 23055539; carries a notice of concern, PMID 34551989
  • Effects of an angiotensin IV analog (PNB-0408/Dihexa) in a rat Huntington-like model. J Huntingtons Dis 2024, PMID 38489193
  • Stem cell, G-CSF and/or Dihexa in rat sciatic nerve repair. Ann Med Surg 2021, PMID 34703584
  • Community reports summarised from public peptide-community notes (peptideprotocols.app page); user reports, not research