About this category
GLP-1 receptor agonists and dual / triple agonists are among the most counterfeited research peptides on the market. Independent purity verification matters because des-amido, oxidized, and truncated impurities are common in poorly synthesized lots and can change pharmacology and stability in research models. Our lab tests semaglutide, tirzepatide, retatrutide, cagrilintide, orforglipron, tesofensine, and related compounds with RP-HPLC for purity, LC-MS/MS Orbitrap for identity, and ICP-MS for residual metals.
Featured peptides we test
Semaglutide
4113.58 g/mol
Semaglutide is a GLP-1 receptor agonist peptide with a long half-life achieved through albumin binding via a C-18 fatty diacid chain. It is one of the most widely studied peptides in metabolic research with extensive clinical data.
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Tirzepatide
4813.45 g/mol
Tirzepatide is a dual GIP and GLP-1 receptor agonist peptide that has demonstrated remarkable efficacy in clinical studies for type 2 diabetes and obesity. It is a first-in-class twincretin combining the actions of both incretin hormones.
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Retatrutide
4177.63 g/mol
Retatrutide (LY3437943) is a novel triple agonist peptide targeting GIP, GLP-1, and glucagon receptors simultaneously. It is one of the most studied next-generation incretin-based peptides, showing significant results in obesity and metabolic disorder research.
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Cagrilintide
~3800 g/mol
Cagrilintide is a long-acting amylin analog being studied for obesity, often in combination with semaglutide (CagriSema). It modulates appetite and gastric emptying via amylin and calcitonin receptor pathways.
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Orforglipron
760 g/mol (approx)
Orforglipron is a small-molecule, oral GLP-1 receptor agonist in late-stage clinical development for obesity and type 2 diabetes. Its non-peptide structure allows true oral dosing without injection.
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Tesofensine
327.25 g/mol
Tesofensine is a small-molecule serotonin-noradrenaline-dopamine reuptake inhibitor studied for obesity. Phase 2 trial data showed substantial weight reduction.
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Sample submission
- Submit 0.5-1 mg of lyophilized peptide for full HPLC + MS panel.
- Blends (e.g. retatrutide/cagrilintide) require 1-2 mg for component-level quantification.
- Reconstituted samples should be shipped cold pack with overnight courier.
Common impurities
- Des-amido and deamidated forms
- Truncated sequences from incomplete coupling
- Oxidized methionine variants
- Residual TFA from cleavage
Recommended tests
- RP-HPLC Purity
- LC-MS/MS Identity
- Residual Solvents (GC-MS)
- Endotoxin (LAL)
All GLP-1 / Metabolic peptides we test (8)
GLP-1 / Metabolic Testing Methodology
Our analytical workflow for glp-1 / metabolic peptides follows USP <1225> guidance for validated chromatographic methods. Every lot is processed by a credentialed analyst with documented chain of custody.
Step 1
Sample intake & cold storage
Each GLP-1 / Metabolic sample is logged with a chain-of-custody ID and stored at -20 °C upon arrival at our Florida lab.
Step 2
Reverse-phase HPLC purity
Samples are run on a C18 column using a water/acetonitrile gradient with 0.1% TFA, with UV detection at 214 nm to quantify main peak purity and named impurities.
Step 3
LC-MS / Orbitrap identity
Observed monoisotopic mass is compared against the theoretical mass for each glp-1 / metabolic compound to confirm identity. Blends are deconvoluted to quantify each active component.
Step 4
Optional residual & endotoxin testing
Residual solvents (GC-MS), residual TFA / acetate counterions, and bacterial endotoxin (LAL) are run on request based on intended downstream use.
Step 5
Signed Certificate of Analysis
Findings are compiled into a signed COA with chromatograms, spectra, instrument metadata, and analyst interpretation, delivered within 9-11 business days.
GLP-1 / Metabolic Purity Notes
Recommended research-grade purity for glp-1 / metabolic peptides is typically ≥ 98% by HPLC area. Synthesis-related impurities are common and only show up under proper analytical scrutiny.
Common impurities to watch
- Des-amido and deamidated forms
- Truncated sequences from incomplete coupling
- Oxidized methionine variants
- Residual TFA from cleavage
What our COA confirms
- Main peak purity by HPLC area %
- Observed vs theoretical monoisotopic mass
- Named impurities ≥ 0.1% area
- Net peptide content where applicable
- Method, column, and instrument metadata
GLP-1 / Metabolic Handling, Storage & Safety
Guidance below is for laboratory and research personnel only. GLP-1 / Metabolic peptides are supplied for research use and are not intended for human or veterinary use.
Storage
Store lyophilized material at -20 °C, protected from light and moisture. After reconstitution, aliquot and store at -80 °C; avoid repeated freeze-thaw cycles.
Reconstitution
Reconstitute in bacteriostatic or sterile water in a clean environment. Allow vials to reach room temperature before opening to prevent moisture condensation on the powder.
PPE & shipping
Handle with gloves, lab coat, and eye protection. Ship samples to ACS overnight on dry ice or cold packs in a rigid, leak-proof container with a packing slip referencing your quote.
This page is informational and does not constitute medical advice. Consult your institution's safety officer and SDS before working with these compounds.
Frequently asked questions
Related testing resources
- HPLC purity testing for glp-1 / metabolic peptides
- Mass spectrometry identity confirmation (ESI-MS)
- Heavy metal and residual solvent screening
- LAL endotoxin testing for injectable peptides
- Peptide testing cost by assay
- How to ship peptides to our lab
- Independent third-party COA verification
- Peptide testing labs near me — all 50 states
- How to read a peptide Certificate of Analysis
- What peptide testing labs measure
Other peptide testing categories
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Healing & Repair Peptide Testing
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Cognitive & Nootropic Peptide Testing
Selank, Semax, Cerebrolysin, Noopept, Dihexa, and related cognitive research compounds.
Immune & Anti-Inflammatory Peptide Testing
Thymosin Alpha-1, Thymulin, LL-37, ARA-290, VIP, and related immunomodulators.
Sexual Health Peptide Testing
PT-141 (Bremelanotide), Melanotan II, Kisspeptin, and related research peptides.
Mitochondrial & Longevity Compound Testing
NAD+, MOTS-c, SS-31, Humanin, 5-Amino-1MQ, BAM15, and related longevity research compounds.
Khavinson Bioregulator Testing
Epitalon, Pinealon, Vesugen, Vilon, Prostamax, Pancragen, and the full Khavinson short-peptide bioregulator family.
Growth & Muscle Peptide Testing
IGF-1 LR3, IGF-1 DES, MGF, PEG-MGF, Follistatin, ACE-031, and Myostatin inhibitors.
Compounded Peptide Blend Testing
Component-level analysis of compounded peptide blends such as Tesamorelin/Ipamorelin and Retatrutide/Cagrilintide.