Peptide testing
Testing a peptide means sending a sample from a vial to an analytical lab, which reports what is in it and how much. Peptide Vendor Reviews publishes thousands of these results for vials bought from shops; before paying for your own test, check whether your peptide or your vendor already has results on record.
This page is informational. We are not accepting sample shipments, taking testing payments, or offering a testing service.
What a peptide test can show
- Purity (HPLC): the share of the sample that is the target peptide rather than synthesis by-products, as a percentage.
- Identity (mass spectrometry): whether the molecule in the vial is the peptide on the label.
- Quantity (fill): how many milligrams the vial actually holds compared with the label.
- Endotoxin and sterility: separate tests that purity and identity results do not cover.
A purity percentage alone does not establish safety, suitability for human use or the quality of a different batch.
Peptide purity testing: choosing a lab
Peptide testing services such as Janoshik and Finnrick, and general analytical labs, test peptide samples for individual buyers. Before choosing one:
- Ask which methods it runs (HPLC, mass spec, quantity) and which peptides and sample types it supports.
- Confirm its current price, turnaround and handling instructions directly; they change.
- Check that it publishes or verifies results, so a certificate can be checked against the lab's own records.
How to send a sample
- Keep the vial sealed and note the vendor, product name, batch or lot number and order date.
- Follow the lab's own packing and shipping instructions exactly.
- Keep the shop's certificate for the same batch, if it provided one, to compare with your result.
How to read peptide test results
Check the batch number matches your vial, the identity result confirms the right peptide, the purity method is named, and the measured amount is close to the label. Results here count a pass at 99.5% purity or more, a fill within 35% of the label and a confirmed identity. How we grade · Understanding a certificate of analysis
Questions about a published result
If a record is incorrect or you have a newer certificate, contact our editorial team with the page and the source document. Do not send physical samples to our correspondence address.