Tested lot by lot

Before any lot goes on sale, a sample goes to an independent lab for the tests below. The lot is listed only if it meets every limit, and its certificate carries the same lot number as your vial.

Release limits are the minimum a lot has to meet. Each lot's measured results are on its certificate. Check a lot.

Why independent testing

A supplier's own certificate isn't an independent result. When outside labs re-test peptides that were bought for research, the gaps show:

  • A university lab re-tested synthetic peptides it had ordered at 95% purity or better. Only 44% met that purity, despite the suppliers' certificates, and the main compound in one sample wasn't the intended peptide at all.1
  • An independent tester has logged 900 results for BPC-157 from 144 online vendors since December 2024. Of the 200 most recent results it lists, 92 failed.2
  • In 2023–24 test purchases of semaglutide from six online sellers, only three products arrived. Each held 29 to 39% more than its label stated, and one carried elevated endotoxin.3

That's why our lots go to an independent lab instead of being tested in-house, why we test for more than purity, and why we publish the full results rather than a summary.

What each test catches

Each test answers a different question, and none can stand in for another. A sample can be 99% pure and still be the wrong peptide, or the right peptide at half the amount on the label.

Identity

Mass spectrometry

Confirms the molecule's mass matches the peptide's sequence. It catches the wrong peptide outright, and the near-misses that synthesis can produce: chains missing an amino acid, carrying an extra one, or still holding a protecting group.4

Purity

HPLC

Separates the target peptide from related impurities and reports its share of the total. In research, closely related sequences can carry activity of their own and skew results.1,4 For comparison, regulators ask makers of synthetic peptide drugs to identify every peptide-related impurity at 0.10% or more.5

Content

Quantitative HPLC

Measures how much peptide is actually in the vial, which purity can't tell you. A freeze-dried peptide also holds water and counter-ions such as trifluoroacetate left from purification, so the powder weighs more than the peptide in it. Counter-ions matter for cell work too: trifluoroacetate has been shown to suppress cell growth at nanomolar concentrations.6

Endotoxin

LAL assay, USP <85>

Measures bacterial endotoxin, the cell-wall material of Gram-negative bacteria, with the pharmacopeial limulus amebocyte lysate method.7 Trace amounts are enough to activate sensitive immune cells in culture and produce misleading data.8

What to look for on any certificate

Use this list to judge any supplier's certificate, ours included. Every Mr. Peppers certificate meets all five.

  • It names the lab that ran the tests. An unnamed lab can't be checked, and an in-house result isn't independent.
  • It carries the lot number on your vial. A certificate for another lot, or for the product in general, says nothing about the vial you have.
  • It tests more than purity. Purity alone can't confirm the peptide is the right one, or that the full amount is in the vial.
  • It shows each method and limit. A result means little without the method that produced it and the limit it was judged against.
  • It can be checked with the lab. A report number the lab will confirm is much harder to fake than a PDF.

Reading a certificate

Every certificate follows the same layout. This specimen shows where to find each part.

Certificate of analysis

Mr. Peppers Peptides

Specimen
Product
BPC-157, 10 mg
1Lot
BPC10-0000X
Date tested
18 Sep 2026
2Lab
Lab name
Report number
000000
Sequence
GEPPPGKPADDAGLV
Test 3Method 4Release limit 5Result Status
Example layout with illustrative values. Not a real result.
  1. 1
    Lot numberMatch it to the label on your vial.
  2. 2
    Lab and report numberWho ran the tests, and the number to verify the report with them.
  3. 3
    MethodHow each result was measured.
  4. 4
    Release limitThe minimum a lot has to meet before it's listed.
  5. 5
    ResultWhat the lab measured for this lot.

Check a lot

Enter the lot number from your vial label to see that lot's certificate.

References

  1. Verbeke F, Wynendaele E, Braet S, D'Hondt M, De Spiegeleer B. Quality evaluation of synthetic quorum sensing peptides used in R&D. Journal of Pharmaceutical Analysis. 2015;5(3):169–181. pmc.ncbi.nlm.nih.gov/articles/PMC5762210
  2. Finnrick. BPC-157: independent test results and vendor ratings. Accessed October 2026; figures change as tests are added. finnrick.com/products/bpc-157
  3. Ashraf AR, et al. Safety and risk assessment of no-prescription online semaglutide purchases. JAMA Network Open. 2024;7(8):e2428280. doi.org/10.1001/jamanetworkopen.2024.28280
  4. D'Hondt M, Bracke N, Taevernier L, Gevaert B, Verbeke F, Wynendaele E, De Spiegeleer B. Related impurities in peptide medicines. Journal of Pharmaceutical and Biomedical Analysis. 2014;101:2–30. pubmed.ncbi.nlm.nih.gov/25044089
  5. U.S. Food and Drug Administration. ANDAs for certain highly purified synthetic peptide drug products that refer to listed drugs of rDNA origin: guidance for industry. May 2021. collections.nlm.nih.gov (archived copy)
  6. Cornish J, Callon KE, Lin CQ, Xiao CL, Mulvey TB, Cooper GJ, Reid IR. Trifluoroacetate, a contaminant in purified proteins, inhibits proliferation of osteoblasts and chondrocytes. American Journal of Physiology. 1999;277(5):E779–E783. Find on PubMed
  7. United States Pharmacopeia. General chapter <85> Bacterial endotoxins test. usp.org/harmonization-standards/pdg/general-methods/bacterial-endotoxins
  8. Schwarz H, Schmittner M, Duschl A, Horejs-Hoeck J. Residual endotoxin contaminations in recombinant proteins are sufficient to activate human CD1c+ dendritic cells. PLoS One. 2014;9(12):e113840. pmc.ncbi.nlm.nih.gov/articles/PMC4257590