I don’t think a research supplier should get points just because the website says:
99% PURE
THIRD-PARTY TESTED
LAB VERIFIED
Those phrases sound good.
They also tell me almost nothing by themselves.
When I’m looking at peptide research documentation, I want to see what’s behind the claim.
Here are the things I care about.
1. Is the testing tied to a specific batch?
This is probably the first thing I check.
If a supplier has a COA posted, I want to know whether that report can actually be connected to the lot or batch being offered.
A beautiful report from six months ago isn’t especially useful if there’s no way to know whether it has anything to do with the current material.
So I look for:
- lot number
- batch number
- sample identification
- testing date
- clear connection between the report and product
Generic COAs aren’t automatically useless.
They’re just substantially less informative.
2. What was actually tested?
This sounds obvious.
Apparently it isn’t.
“Third-party tested” does not tell me what was tested.
I want to know whether the report evaluated:
- chromatographic purity
- identity
- peptide content
- residual solvents
- water
- some other characteristic entirely
Different analytical procedures answer different questions.
ICH guidance specifically emphasizes that analytical procedures need to be appropriate for the characteristic being evaluated and sufficiently selective for their intended purpose. (ICH Database)
So the presence of a lab logo isn’t enough for me.
I want to know what the lab actually did.
3. Is there analytical data?
If a report says:
Purity: 99.5%
I would much rather see the chromatogram than just the number.
Same thing with mass spectrometry.
Show me the spectrum.
The point of testing isn’t to generate a marketing badge.
It’s to generate data.
4. Was identity evaluated separately?
This is one of the biggest things I think gets overlooked.
A high-purity chromatographic result is useful.
But purity and identity are not the same thing.
ICH guidance specifically discusses identification testing and notes that analytical procedures should be capable of identifying the analyte based on unique structural or other specific properties. (ICH Database)
So ideally I want to see some evidence supporting both:
purity
and
identity
rather than treating one as proof of the other.
5. Can I identify the testing laboratory?
I don’t necessarily need a glamorous laboratory.
I want transparency.
Who performed the testing?
When?
What methodology was used?
Does the laboratory actually exist?
Can the report be independently understood?
A report with absolutely no identifying information is harder to evaluate than one with clear laboratory details.
6. Does the documentation make sense as a whole?
This sounds subjective, but it matters.
Do the batch numbers match?
Do the dates make sense?
Does the product name match the report?
Does the reported molecular mass make sense?
Does the purity result correspond to actual data?
Are reports being recycled across multiple listings?
You don’t have to be an analytical chemist to notice when documentation doesn’t line up.
7. Does the supplier explain what the testing does NOT establish?
This is actually something I respect.
Testing should be presented with limitations.
A 99% HPLC result doesn’t prove every possible characteristic of the sample.
Mass spectrometry doesn’t answer every purity question.
One report rarely tells you everything.
USP’s work characterizing synthetic peptide reference standards is a good example of how many analytical measurements can be involved when a peptide needs to be characterized carefully. (USP)
FDA guidance regarding regulated synthetic peptide drug products similarly discusses peptide-related impurities and manufacturing-related substances as separate quality considerations. (U.S. Food and Drug Administration)
That’s why I get skeptical when one number is presented as if it answers every question.
My basic checklist
When I’m evaluating research documentation, my checklist is pretty simple:
Can I identify the batch?
Can I identify the lab?
Can I see the actual data?
Was purity evaluated?
Was identity evaluated?
Does everything match?
Are the limitations clear?
If I can’t answer those questions, I’m not necessarily saying the material is bad.
I’m saying:
I don’t have enough information to know.
And there’s a difference.
The bottom line
Good research documentation should make it easier—not harder—to understand what was tested.
I don’t care how many giant “LAB TESTED” badges are on a website.
Show me the report.
Show me the batch.
Show me what was tested.
And tell me what the results establish.
That’s the standard I’ll use whenever Pep Compass looks at research-supplier documentation.
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