Research peptide suppliers, read against their own lab reports.
We go through the certificates, testing notes and policies each supplier publishes and set out what holds up. Our guides show you how to check the same paperwork yourself.
Seven checks on every supplier
Scores weigh what a lab can verify most heavily: who did the testing, whether the report matches the batch, and whether identity was confirmed.
- Independent lab testing
- Testing done by a lab that is not owned by the seller, and named on the report.
- Batch-specific COAs
- A certificate of analysis for the actual batch on sale, with a batch number you can match to the vial.
- Identity confirmed by mass spec
- Mass spectrometry results showing the molecule is the one on the label, not just a purity percentage.
- Research-use labeling
- Clear research-use-only labeling on the site and products, with no dosing advice or health claims.
- Age and use confirmation
- An age check and a research-use acknowledgement before purchase.
- Clear shipping and refund terms
- Written shipping, storage-in-transit and refund or reship policies that are easy to find.
- Business transparency
- A real contact route, a stated business location and terms of sale.
Supplier files
28 of 97 suppliers show independent testing with batch-specific certificates. Sorted by score.
| Supplier | Score | Independent testing | Batch COAs | Identity by mass spec | Ships from | Supplier file |
|---|---|---|---|---|---|---|
| IDUN Peptidesidunpeptides.shop | 4.4/5 | Yes | Yes | Yes | United States | Read file |
| Ascension Peptidesascensionpeptides.com | 4.3/5 | Yes | Yes | Yes | United States | Read file |
| Index Peptidesindexpeptides.uk | 4.3/5 | Yes | Yes | Partly | United Kingdom | Read file |
| Averix Labsaverixlabs.com | 4.2/5 | Yes | Yes | Partly | Not stated | Read file |
| Axis Peptide Labsaxispeptidelabs.com | 4.2/5 | Yes | Yes | Partly | Not stated | Read file |
| Biotech Peptidesbiotechpeptides.com | 4.2/5 | Yes | Yes | Yes | United States | Read file |
| NuNu Researchnunuresearch.com | 4.1/5 | Yes | Yes | Partly | United States | Read file |
| Peptide Giantspeptidegiants.com | 4.1/5 | Yes | Yes | Partly | United States | Read file |
| Amino Researchofficialamino.com | 4.0/5 | Yes | Yes | Partly | United States | Read file |
| Eon Peptideseonpeptides.com | 4.0/5 | Yes | Yes | Partly | Not stated | Read file |
| HEEZ Researchheezresearch.com | 4.0/5 | Yes | Yes | No | United States | Read file |
| Medvinci Researchmedvinciresearch.com | 4.0/5 | Yes | Yes | Not shown | Not stated | Read file |
Guides for checking the paperwork
Plain-language explainers on lab reports, labeling and handling. No dosing, no protocols.
How to Read a Certificate of Analysis for Research Peptides
A field-by-field walk through a peptide COA: what each line means, what a complete result looks like, and what the document can't tell you.
HPLC and Mass Spec Explained: The Two Tests Behind a Peptide COA
HPLC tells you how much of a sample is the main compound. Mass spec tells you whether that compound is the right molecule. Here is how to read both.
Third-Party vs In-House Testing: What the Difference Means
Who ran the test and who chose the sample matter as much as the purity figure. Here is how in-house and independent testing differ, and how to weigh them.
What “Research Use Only” Means on a Peptide Label
Research use only is a statement of intended use, not an approval or a quality grade. Here is what the label does and doesn't mean, and how regulators read it.
Peptide Purity Percentages Explained: What 98% and 99% Mean
A purity figure is a share of peak area on an HPLC trace, not a measure of how much peptide is in the vial. Here is what the numbers mean and what they leave out.
How to Verify a Certificate of Analysis and Spot a Fake
Simple checks that catch most fake or recycled certificates: matching batch numbers, confirming the report with the lab, and spotting signs of reuse or editing.
A research guide, not a health site
Peptides from the suppliers on this site are sold for laboratory research. They are not approved medicines, and they aren't made or tested to the standards needed for use in people or animals.
That's why InhousePep never publishes dosing, injection or stacking information, never describes effects in the body, and leaves out suppliers that publish dosing tools or market products for weight loss and other body goals. Stores that also sell sprays, pens or capsules are marked as failing research-use labeling. If you're interested in a peptide for a health reason, talk to a licensed clinician about approved options.