Suppliers, purity and what is actually in the vial
There is no vendor list at the bottom of this page, and that is deliberate. Quality in this market turns over in months — sourcing changes, ownership changes, a good name coasts while the product slides. Any ranking published today is misleading by spring, and it would be our name sending you somewhere bad. So instead of an opinion you cannot check, here is the instrument: learn to read the paperwork, then score whoever you are considering yourself.
Two questions, two instruments
Almost everyone conflates these, and the entire scam economy lives in the gap.
HPLC
“How much of this is one thing?”
Separates everything that absorbs UV and reports what fraction is a single compound. It is a purity measurement. It has no idea what that compound is — it only knows one thing dominates.
Mass spec
“Is it the right thing?”
Weighs the molecule and compares it to what the label claims. This is the identity check, and nothing on a chromatogram substitutes for it.
A 99% pure vial of the wrong peptide passes every purity test ever devised.
If a certificate shows you purity and nothing else, it has told you the vial is consistent. It has not told you what it is consistent about. Ask for the mass spec.
Reading a chromatogram
Time runs left to right; the detector response runs up. Your peptide comes off the column at a characteristic time and everything else in the vial shows up as its own peak. The purity figure is just the main peak’s share of the total area.
The same peptide, two batches
Sharp, symmetrical main peak on a flat baseline. The small neighbours are integrated and declared, which is what honest integration looks like.
Check the wavelength
214 nm detects the peptide bond itself, so every peptide species shows up. At 280 nm you only see tryptophan and tyrosine — any impurity without them is invisible, and the number flatters systematically.
Check the gradient
A shallow gradient over 30 minutes resolves close impurities. A steep 5-minute flush merges them into the main peak. The same vial can honestly read 94% or 99% depending on method.
Small peaks are a good sign
A real 98% trace has visible neighbours. A perfectly clean trace with a single peak and no integration table usually means nobody looked, not that nothing is there.
Purity is not quantity
A vial labelled 10 mg contains 10 mg of powder. Some of that is counterion, some is residual water, some is bulking agent. The peptide itself is commonly 75–90% of it. HPLC cannot see this — counterion and water have no chromophore, so they contribute exactly zero peak area. A vial can be 99% pure and 78% peptide at once, and both numbers are honest.
Every reconstitution calculator, including ours by default, assumes the label is net peptide. If it is not, every dose you draw runs under.
Your vial
What you would draw
10 units
believing the label
delivers 400 mcg
What actually hits the target
13 units
corrected for net content
delivers 500 mcg
Grade a certificate
Two verdicts, kept deliberately apart: how far the document can be trusted, and — separately — what it says about the vial. A fabricated certificate claiming 99.9% should not score well because the number is high, and a scrupulous report showing 94% should not be dismissed because the number is low.
What does your certificate say?
Purity
Identity
Provenance
Traceability
Quantity
Can you trust this document?
This document is not evidence of anything. Treat the vial as untested.
And what does it say about the vial?
The document is not trustworthy enough for its numbers to mean anything about the vial.
- There is no identity evidence at all. This certificate can only tell you that something in the vial is pure — not that it is the peptide you ordered.
- No lot number on the report. It cannot be tied to any particular batch, which is what makes recycled certificates possible.
- No purity figure is stated.
- This is a vendor-issued certificate. It is marketing until an independent lab says the same thing.
- The testing laboratory is not named, so nothing here can be verified with anyone.
- Purity without a quantity assay tells you nothing about how many milligrams are actually in the vial.
- Salt form is not stated. Residual TFA is the usual cause of injection-site burning people blame on the peptide.
Red flags, sorted by how much they should stop you
Dealbreaker
- ·The same chromatogram image, down to the noise, appears on certificates for different lots or different peptides.
- ·The lot on the report does not match the lot on the vial.
- ·Purity is claimed with no chromatogram attached at all.
- ·The product arrives pre-reconstituted, or as a ready-made nasal spray.
- ·They will not name the testing laboratory.
Serious
- ·No mass spectrometry anywhere in the package — purity without identity.
- ·Purity measured only at 280 nm, which cannot see non-aromatic impurities.
- ·No gradient or column method, so the purity figure cannot be interpreted.
- ·Vials arrive with blank or handwritten labels.
- ·Marketing makes therapeutic claims or suggests human doses.
Worth noting
- ·Cryptocurrency is the only payment method offered.
- ·The vendor is new, or recently changed hands.
- ·Purity stated to two decimal places, which routine RP-HPLC does not resolve.
- ·No written policy on what happens if independent testing fails.
Score a supplier
Drop in a supplier’s address and we will read their public pages and fill in whatever they have published. Everything we cannot prove from their own words stays blank for you to check by hand. Eighteen criteria, weighted by how well each actually predicts that the vial contains what the label says — not by how easy it is to check.
Reads up to 60 of their pages, opens any certificates they publish as PDFs, looks up the domain registration, and matches their catalogue against our compound database. Detection is pattern-based, not an AI reading the page — a site cannot talk its way into a better grade.
Score
—
You have answered less than half the weight on this list. That is not a score, it is a gap — work through the unknowns before you decide anything.
Heaviest thing you still do not know: Third-party analytics
- 5
Third-party analytics
Are purity and identity reports issued by a named outside laboratory rather than the vendor?
A vendor grading its own homework is marketing. Everything else on this list matters less than this.
- 5
Batch-specific reporting
Does the report reference the exact lot number printed on the vial you would receive?
A report that is not tied to your lot describes someone else’s material. This is what makes recycled certificates work.
- 5
Testing lab is named and reachable
Is the lab named in full, with an address or website you could actually contact?
An unverifiable lab is indistinguishable from no lab.
- 5
Quantity assay, not just purity
Is there a quantitative result stating how many milligrams of peptide the vial contains?
Purity tells you what fraction of the UV-absorbing material is your peptide. It says nothing about how much is in the vial.
- 5
Response to a direct analytics request
When you email asking for the batch report for the specific lot you would receive, what happens?
This single email separates vendors faster than any amount of forum reading. Legitimate operations answer it easily.
- 4
Lot number physically on the vial
Do vials arrive with a lot number on the label that matches the paperwork?
Without it you cannot connect anything you were sent to anything you were told.
- 4
Identity confirmed by mass spectrometry
Does the package include a mass spec result confirming the molecular weight?
HPLC measures purity, not identity. A 99% pure vial of the wrong peptide passes it cleanly.
- 4
Net peptide content disclosed
Do they state whether the labelled milligrams are net peptide or gross powder?
The difference is commonly 10-25% of your dose, and almost nobody discloses it unprompted.
- 4
Lyophilised, not pre-mixed
Does it ship as dry powder rather than pre-reconstituted liquid?
Peptides degrade in solution. Shipping them wet means you have no idea what is left on arrival.
- 4
Independent customer tests exist publicly
Have customers, not the vendor, sent this product to a lab and published results?
The only evidence not controlled by the seller. Recency matters — quality changes with ownership and sourcing.
- 3
Salt form disclosed
Do they state the salt form, typically trifluoroacetate or acetate?
Residual TFA causes much of the injection-site burning people blame on the peptide itself.
- 3
Vial presentation and seal
Do vials arrive crimp-sealed with intact flip-tops and undisturbed stoppers?
A compromised seal means you cannot rule out that the vial was opened, and a proper vial pulls diluent in under vacuum.
- 3
Storage and shipping practice
Do they describe how product is stored and how it is packed for transit?
Lyophilised peptide is more robust than folklore suggests, but a vendor who cannot describe their own process usually does not have one.
- 3
Operating history and continuity
How long has this vendor operated under this name and ownership?
Reputation attaches to a name, but quality attaches to whoever currently controls sourcing. A handover resets everything.
- 3
Refund and test-failure policy
Is there a written policy covering what happens if an independent test fails?
A vendor confident in their material will stand behind it. It also tells you they expect to be tested.
- 3
Marketing restraint
Does the site avoid therapeutic claims, promised outcomes and suggested human doses?
A vendor making medical claims has already shown you their relationship with regulators and with the truth.
- 2
Sterile filtration claims are substantiated
If they claim sterile filtration or aseptic filling, can they describe or evidence it?
An unsubstantiated sterility claim is worse than no claim, because it invites you to skip precautions.
- 2
Payment methods
Can you pay by means other than cryptocurrency?
Weak on its own — plenty of legitimate vendors take crypto for processing reasons. But crypto-only removes every avenue of recourse.
The one email
This settles most of the list above in a single reply. Legitimate vendors answer it without friction.
Subject: Third-party analytics for the lot I would receive Hello, Before ordering I would like to see the analytical package for the specific lot you would ship me, rather than a general product report. Could you send: 1. The HPLC purity report, including the chromatogram, the integration table and the gradient method, with the detection wavelength stated. 2. The mass spectrometry result confirming molecular weight — expected and found. 3. The lot number these reports correspond to, so I can check it against the vial. 4. The name of the laboratory that ran them. 5. Whether the labelled milligrams are net peptide or gross powder, and the salt form. If any of these are not available for the current lot, just tell me which — I am trying to understand what is documented, not catch anyone out. Thanks.
Why there is no list here
We could name suppliers. We would be guessing. We cannot see anyone’s current batches, quality in this market changes faster than any page gets updated, and a recommendation that goes stale is worse than no recommendation — it carries authority it no longer deserves. The tools above will still be right next year. A vendor list would not be.
Once you have a vial in hand, work out your actual dose — and set net peptide content if your certificate states it.