P21 lab test results by vendor
How each vendor's P21 held up in independent third-party lab tests: purity, dose against the label, and how often vials failed.
- vials tested
- 3
- lab reports
- 2
- vendors
- 2
- of vials failed
- 0.0%
- median purity
- 95.19%
- median dose vs label
- +14.5%
Specification: when a vial fails
A vial fails if it's empty, under 95% pure, more than 20% under its label, or more than 50% over.
- Contentsempty
- Purity< 95%
- Dose vs label< −20%
- Dose vs label> +50%
0 of 3 vials failed. Results from Jul 2026 to Aug 2026.
For research use only. Vendors can't pay to change their score, rank or warnings. No affiliate links, no coupon codes, no paid rankings. How scores work
Key facts
- VendorVerify holds lab results for 3 P21 vials from 2 vendors, from 2 independent lab reports dated Jul 2026 to Aug 2026.
- 0.0% of P21 vials on file failed (0 of 3), meaning empty, under 95% pure, more than 20% under label or more than 50% over.
- The median P21 vial on file tested at 95.19% purity.
- The median P21 vial on file held +14.5% compared with the amount on its label.
- No vendor yet has the 5 independent P21 lab reports needed to be ranked for P21.
P21 vendors
| # | Vendor | Verdict | Score | Failed vials | Lab reports | Median dose vs label | Avg. purity | Vendor page |
|---|---|---|---|---|---|---|---|---|
| Not enough data to rank (fewer than 5 independent lab reports) | ||||||||
| PGB | Not ranked | 87.8 | 0.0% | 1 | +12.4% | 98.27% | View vendor PGB | |
| Bluum | Not ranked | 86.9 | 0.0% | 1 | +18.4% | 95.16% | View vendor Bluum | |
Every P21 vial against its label
One dot per vial, placed by how much it held compared with the amount on the label. 100% held more than the label and 0% held less. The ones to worry about sit on the left.
Dot chart of 3 vials (every P21 vial on file), each placed by its measured amount compared with the label, from 50% under to 50% over. 0 are within 5% of the label, 3 are 5 to 20% under or more than 5% over, 0 are more than 20% under, 0 are more than 50% over, and 0 were empty.
What an honest P21 lab report should show
Use this list on the report a vendor sends you, before you trust the numbers on it. How to read a COA
- Lot match. The lot or batch number on the report matches the one printed on your vial.
- Named, independent lab. The report names a lab you can contact and check it with. A PDF with only the vendor's logo doesn't count.
- HPLC and mass spec. HPLC measures purity and mass spectrometry confirms identity. You need both.
- Recent, batch-dated test. The test is dated for this batch, not one report reused for years.
- Purity isn't identity. A high purity figure says nothing about what the compound is unless the mass spec result matches it.
- Contaminants. Endotoxin, heavy metals and sterility results, where the lab offers them. Most reports leave these out.
P21-specific things to check
No P21-specific notes yet.
P21: common questions
Which P21 vendors pass lab testing?
No vendor has 5 or more independent lab reports for P21 yet, so none is ranked. The table on this page lists every vendor's results so far.
How often do P21 vials fail testing?
0 of 3 P21 vials on file failed (0.0%). A vial fails if it's empty, under 95% pure, more than 20% under its label, or more than 50% over it.
Are P21 vials underdosed?
Usually not; if anything they run over. The typical P21 vial on file held +14.5% compared with the amount on its label. Individual vials vary much more than that, and the chart on this page shows every one.
What purity do P21 vials test at?
The median P21 vial tested at 95.19% purity. We count anything under 95% as a failed vial and give full marks for purity at 99.5% or higher, because small differences above that are within normal lab-to-lab variation.
Where do these P21 results come from?
From 2 independent lab reports, mostly commissioned by buyers, covering 3 vials from 2 vendors, dated Jul 2026 to Aug 2026. VendorVerify doesn't test anything itself. A report a vendor paid for is only used if the lab can verify it, and it is marked as vendor-commissioned and counts at half weight.
Does VendorVerify sell P21?
No. VendorVerify doesn't sell peptides of any kind. Vendors can't pay to change their score, rank or warnings. No affiliate links, no coupon codes, no paid rankings.
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