Question 1

What is Dihexa?

Accepted Answer

Dihexa (PNB-0408) is a small-molecule hexapeptide-like analog of angiotensin IV developed at Washington State University by the Harding/Wright group as a preclinical candidate for Alzheimer's disease and cognitive decline. It is NOT FDA-approved and has never been tested in human clinical trials. The often-quoted claim that it is 'roughly ten million times more potent than BDNF' refers to EC50 comparisons in an in vitro dendritic spine assay, not clinical efficacy. Merit Verified tracks independent COA test results for Dihexa from multiple vendors.

Question 2

Which vendors sell Dihexa with independent COA testing?

Accepted Answer

4 vendors in the Merit Verified directory have independent COA evidence on file for Dihexa — 10 COAs total. COA coverage and test dates are listed on the Dihexa page at https://meritverified.org/peptides/dihexa.

Question 3

How do I verify the quality of Dihexa from a vendor?

Accepted Answer

To verify Dihexa quality, look for an independent certificate of analysis (COA) from a third-party lab — not a lab the vendor owns or pays directly. The COA should state the tested compound, lot number, purity percentage (identity and concentration), and the lab's name. Cross-reference the lot number against the vendor's current stock. Merit Verified indexes COAs for Dihexa at https://meritverified.org/peptides/dihexa so you can compare evidence across vendors before buying.

Question 4

What is the regulatory status of Dihexa?

Accepted Answer

Dihexa is tracked in the Merit Verified registry. Regulatory status for research peptides in the US has been evolving — the FDA has reclassified a number of peptides out of the 503A compounding ingredient list since 2025. Merit Verified does not provide legal or regulatory advice; check official FDA sources or consult a licensed professional for the current status of Dihexa in your jurisdiction.

	Vendor	Price	$/mg	vs avg	Purity	COAs	Merit
🇺🇸	Moglabs via Disclosed Labs · just now	$40.00· 150mg	$0.27/mg	-97.5%	99.6%	2	96
🇺🇸	Licensed Peptides ✓ verified at source · just now	$130· 10mg	$13.00/mg	+21.4%	—	2	95
🇺🇸	Peptidology ✓ verified at source · just now	$69.99· 10mg	$7.00/mg	-34.6%	—	—	89
🇺🇸	Certified Peptides ✓ verified at source · just now	$240· 50mg	$4.80/mg	-55.2%	—	—	62

Dihexa

Pricing for Dihexa

COAs for Dihexa

12 citations indexed for Dihexa

Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions

Umbilical cord mesenchymal stromal cells-derived HGF inhibits STING-mediated pyroptosis to alleviate cerebral ischemia/reperfusion injury via c-Met/β-catenin/RNF5 pathway

Comparative analysis of small molecule and growth factor-derived human induced pluripotent stem cell-derived hepatocyte-like cells

Generation and applications of an expandable and mature hiPSC-derived liver organoid

The Occurrence of Illicit Smart Drugs or Nootropics in Europe and Australia and Their Associated Dangers: Results from a Market Surveillance Study by 12 Official Medicines Control Laboratories

Effects of an Angiotensin IV Analog on 3-Nitropropionic Acid-Induced Huntington's Disease-Like Symptoms in Rats