The triple-agonist peptide labs keep re-ordering.
A 39-residue GIP / GLP-1 / glucagon agonist with independently verified 99.745% HPLC purity. Here's what makes researchers switch — and what to check before you buy any peptide online.
The Brief
Why "purity" is the only number that matters.
The research peptide market has a problem most buyers don't see until they're three vials deep: opaque sourcing. A peptide labeled "99% pure" with no certificate, no lot number, and no mass-spec data is, functionally, an unknown compound.
That's why we keep coming back to one specific batch of GLP-3R — a 39-residue triple agonist targeting GIP, GLP-1, and glucagon pathways — supplied by Sourced Peptides. It's the rare listing that actually backs the marketing with paperwork.
"Highest purity I've tested." — Verified buyer, independent lab
Every batch
HPLC-UV, mass spectrometry, heavy metals, endotoxins, microbials.
Independent third-party labs. Full certificate available for every lot before you reconstitute.
A 6-point check
How GLP-3R from Sourced Peptides compares to the industry average.
Sourced Peptides
6 / 6 standards met- ✓≥99% purity — CoA verified
- ✓Full contaminant screening
- ✓cGMP-compliant manufacturing
- ✓Consistent batch potency
- ✓BAC water available
- ✓ISO-aligned certification
Industry average
0 / 6 standards met- ✕Unverified purity
- ✕No safety testing
- ✕Opaque supply chain
- ✕Variable potency
- ✕No BAC water offered
- ✕No certifications
Verified researcher feedback
Exactly what was advertised
Verified purity, well packed. CoA matched. Reconstituted cleanly with the included BAC water.
Highest purity I've tested
Ran independent HPLC against three other vendors. This one came out on top, not even close.
Worth the price
The bundle pricing is competitive and the consistency batch-to-batch is what keeps me ordering.
Limited stock at this price
Ready to see the certificate?
View live pricing, the full Certificate of Analysis, and bundle options — including 6-vial packs with free BAC water.
View GLP-3R on Sourced Peptides →