Research peptides in BaliFor research use only21+ only

Journal · Buying

Eight checks before you trust a peptide supplier

Trust lot-specific reports from an independent lab, with a full panel you can check at the lab, from a supplier who also shows weaker results.

By Published Last updated 2 min read

An old folding magnifying loupe with three lenses
An old folding magnifying loupe with three lenses. Photo: Marie-Lan Taÿ Pamart, CC BY 4.0, via Wikimedia Commons

Key takeaways

  • A trustworthy report is for your lot, from an independent lab, and can be checked at the lab.
  • A complete panel answers five questions; a purity figure answers one.
  • Honest suppliers also show the gaps and the weaker results.

Labels and prices are easy to copy. These eight checks are not.

1. The report is for your lot

A certificate of analysis is issued for one batch[1]. The lot code on the report must match the code on the vial. A generic report, or one for a different lot, does not count.

2. The lab is independent

A lab owned by the seller has an interest in the result; a named third-party lab does not. BP's reports are issued by Janoshik Analytical[2].

3. You can check the report at the lab

There is a task number and a key, and the lab's own page shows the same report[3]. If you can only see a PDF, you cannot check it. How to check a report

4. The panel is complete

Identity, purity, measured content, contaminants, endotoxin, heavy metals and microbial counts (Figure 1). A purity figure alone is one answer out of several. Why purity is not enough

  • PurityHPLC, the main peak's share.
  • IdentityLC-MS: is it the right compound?
  • EndotoxinEU per vial, from Gram-negative bacteria.
  • Heavy metalsAs, Cd, Pb and Hg.
  • Microbial countsTAMC and TYMC.
Figure 1. The tests on each BP report, and the question each one answers. Source: Janoshik Analytical reports in the COA library.

5. The numbers are honest

Measured content that sometimes falls below the label is a good sign: it shows the supplier publishes what the lab found. Content that always equals the label to the digit is not. Content versus the label

6. The gaps are shown

Not every report says everything, and not every product has every test. A supplier who marks the gaps, rather than hiding them, is easier to believe.

7. Storage and shipping are explained

Heat and moisture break peptides down, even when they are dry[4]. Ask how vials are kept and how they travel. Storage in a hot climate

8. No health claims

Research materials are not medicines. A supplier that promises a product treats, cures or improves a condition is describing a use, not a research material. Be careful with it.

And the price

A very low price next to full independent testing does not add up. Testing every lot costs money, and it shows in the price.

Check it on real reports. The COA library has the full lab reports for 11 lots, with the original PDFs and links to the lab's own copies. Open the COA library

Sources

  1. ICH. Q7: Good manufacturing practice guide for active pharmaceutical ingredients. Step 4 version, 10 November 2000. Section 11.4, Certificates of Analysis. database.ich.org (PDF)
  2. Bali Peptide Supply. COA library: every lab report for the lots sold on this site. Reports issued by Janoshik Analytical, with their task numbers, keys and original PDFs. balipeptidesupply.com/coa/
  3. Janoshik Analytical. Verification of test reports. Verification page (task number and unique key) and the lab's copies of BP's reports. janoshik.com/verification
  4. Lai MC, Topp EM. Solid-state chemical stability of proteins and peptides. Journal of Pharmaceutical Sciences 1999;88(5):489-500. doi.org/10.1021/js980374e

Each source was read in its own document on 16 Oct 2026. Numbers about BP's lots come from the reports in the COA library.

How this article was made

Written by Bali Peptide Supply from the sources listed above, each read in its own document on 16 Oct 2026. Every number about our lots comes from the Janoshik Analytical reports in the COA library, read by the site build, not typed by hand. The lead photo is from Wikimedia Commons under a free licence.

BP sells research materials for laboratory use only. This article explains laboratory testing and lab reports. It is not medical advice and not instructions for use.

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