PeptideCompareHow we rank. Why it matters.
PeptideCompare is an independent peptide comparison initiative. Our independence isn't about keeping suppliers at a distance — it's about how we assess, rank and verify. We stay open to working closely with suppliers in whatever way helps researchers, while keeping our judgment entirely our own. Our standards define exactly how we assess, rank and verify every product and supplier.
The ranking formula
Every price row is scored on three weighted factors. A lower price is rewarded, but never at the expense of purity or independent verification.
€/mg relative to the cheapest verified option in the same size class.
COA-stated purity %, with a bonus for independently confirmed lab values.
COA presence, lab independence, and whether the product was personally ordered and checked.
Prices are now maintained on PeptideSupply.eu, a PeptideCompare platform. Keeping all prices in one central place lets us offer the best quality: one clear, up-to-date overview.
How to read the score
On PeptideSupply.eu every offer shows the price together with the PeptideCompare verification marks. This is what an offer list looks like:
| # | Supplier | Strength | Price | €/mg | COA | Verification |
|---|---|---|---|---|---|---|
| 1 | Supplier A | 10mg | €24.99 | €2.50 | ✔ COA | CMI Verified ✓ Product Verified |
| 2 | Supplier B | 10mg | €27.50 | €2.75 | ✔ COA | CMI Verified |
| 3 | Supplier C | 10mg | €29.99 | €3.00 | — Pending | — |
Per supplier: confirmed, direct contact with the supplier through an order or another verified interaction, and a real shipment assessed firsthand on arrival and unboxing.
Per product: we have checked this product ourselves on quality within the past year.
Example for illustration. Suppliers without a mark have not been verified yet; that says nothing bad about them.
Supplier? Send an independent COA via our contact page.
Four levels of certainty
Every badge is earned through independent verification — not purchased, not self-reported.
CMI Verified
Confirmed, direct contact with the supplier — through an order or another verified interaction. A real shipment received from them, assessed firsthand on arrival and unboxing.
COA Verified
A Certificate of Analysis from an accredited independent lab is on file and isn't older than 12 months — and we follow up directly with suppliers who don't have one yet.
Product Verified
Independently assessed on reconstitution, appearance, and post-reconstitution stability under refrigeration. No human or animal testing.
Most Extensively Tested
Goes beyond purity alone: a full test panel per batch covering identity, 7 heavy metals, endotoxins & microbial — verified via Liquilabs.
What "Product Verified" checks for a peptide vial
Three things determine whether a batch earns the badge — the same criteria used across every verified product.
Reconstitution
Does the freeze-dried powder dissolve fully and clearly in bacteriostatic or sterile water — no clumping, floating particles or cloudiness?
Appearance
A properly freeze-dried "cake" is uniform, intact and fills the vial. Shrinkage, crumbling or discolouration (yellow/brown) often points to heat exposure or a poor lyophilisation cycle.
Post-reconstitution stability
Once dissolved, does the solution stay clear over several days to weeks in the fridge — the exact window depends on the compound — or does precipitate or cloudiness appear? This is the real test of whether a product holds up over a normal usage period.
Data policy
Update frequency
Prices are manually checked and updated monthly. Suppliers can always reach out to request a correction if something's inaccurate.
COA Update
We check whether a supplier's COAs are still present and current: not older than a year, or already replaced by a new COA following a new production batch.