Peptide Watchdogs
Price index / Dihexa
Nootropic

Dihexa

Also known as PNB-0408

CAS 1401708-83-5 Also sold as PNB-0408

A nootropic research peptide. Current market pricing by vial size, and vendor listings as they are verified.

For research use only. Not for human consumption. No health, dosing, or usage claims are made.

What Dihexa is

Dihexa (PNB-0408) is an orally active, blood-brain-barrier-penetrant small-molecule analog of angiotensin IV, studied as a nootropic / synaptogenic agent in animal cognition models. It was originally proposed to act through the hepatocyte growth factor (HGF)/c-Met system, but the two foundational papers underpinning that mechanism were retracted in April 2025. It is a research chemical with no published human trials and is not FDA-approved.

TypeNot a classic peptide; a small-molecule oligopeptide analog (two amino-acid-derived residues with a hexanoyl cap and an aminohexanoic amide tail)
Molecular formulaC27H44N4O5
Molecular weight504.66 g/mol
CAS number1401708-83-5
Amino-acid sequenceNot a classic peptide — N-hexanoyl-Tyr-Ile-(6)-aminohexanoic amide, an angiotensin IV-derived analog.
CategoryNootropic

Regulatory status: Not FDA-approved and has no IND or NDA as of 2026. It is sold only as a research-use-only chemical, with no human safety, toxicology, or pharmacokinetic data.

Vial price (low)
$55
Vial price (high)
$180
Vial sizes
10, 20 mg
Vendors listing
—
Verified
—

Price by vial size

sourced market ranges · Jul 2026
10 mg vial
$55–$110
20 mg vial
$90–$180

Typical vendor vial prices, Jul 2026. Exact prices load with verified listings.

Compare vendors

vendor prices · lowest first
VendorVial priceCoupon
Simple Peptide
$0.05Best — View vendor ›
Precision Research Peptides
$0.13 WATCHDOG20 View vendor ›
Prime Lab Peptides
$0.16 — View vendor ›
Koi Peptides
$0.18 — View vendor ›
Protide Health
$0.20 — View vendor ›
BioInfinity Lab
$0.22 — View vendor ›
Kaia Peptides
$0.33 — View vendor ›
BioLongevity Labs
$0.50 — View vendor ›
Mile High Compounds
$1 — View vendor ›
PSPeptides
$3.60 — View vendor ›
Skye Peptides
$8.80 — View vendor ›
Comparing vial prices. Vial price is what you actually pay — no derived math to get wrong. Just match the vial size across vendors: a 10 mg vial against another 10 mg vial. Sizes for this compound are listed above. Need to plan a reconstitution? Use the calculator.

Where it shows up in research

literature areas · not a health claim
Nootropic and cognitive-enhancement researchSynaptogenesis and neurotrophic-signaling studiesNeurodegeneration (Alzheimer's) models

These are areas where the compound appears in the scientific literature, largely in animal and cell studies; note that key mechanistic papers were retracted in 2025. Listing a research area is not a health claim and does not indicate any effect you should expect.

Storage & handling

Planning a reconstitution? Use the calculator — it is math for handling a vial, not dosing.

Looking at this for yourself? Dihexa is a research compound — whether it is right for a person is a medical question we cannot answer. Talk to a licensed clinician. Everything on this page is for laboratory research use only.

Sources & further reading: PubChem CID 125355097 — dihexa (PNB-0408) identity (NCBI) · Dihexa — overview (Wikipedia)
How we source this ›

Frequently asked

How much does Dihexa cost?
About $55–$180 per vial, depending on vial size. Compare the same size across vendors.
Why do Dihexa prices vary so much?
Vial sizes differ, so always compare the same vial size across vendors. Batch testing, stock, and pack discounts move the true cost too — see what "Verified" means.
How are Dihexa vendors verified?
A vendor earns a Verified badge only after independent batch testing (HPLC purity + mass-spec identity) checks out against its COA. Verification is never for sale.

Related compounds

Nootropic
Selank $40+ / vial Semax $55+ / vial