GLP-3RT is a retired listing name. The material is listed as GLP-3, CAS 2381089-83-2. Six lots, three independent laboratories, 99.375–99.946% measured purity.
- CAS Number
- 2381089-83-2
- Molecular Formula
- C221H342N46O68 C221H342N46O68
- Molar Mass
- 4731.3 g/mol
GLP-3RT is a retired product-listing name. The material is now listed as GLP-3, and its unambiguous identifier is CAS 2381089-83-2.
If you found that term in a catalogue, a spreadsheet, or an older reference, the CAS number is what to carry forward. Listing names vary between suppliers and change over time. A registry number does not.
This page covers what the designation meant, how to confirm identity independently, and the measured purity data from six lots tested by three separate laboratories.
Key points
- GLP-3RT is a retired listing name. The current listing is GLP-3.
- Registered as CAS 2381089-83-2. Formula C221H342N46O68, molar mass 4731.3 g/mol.
- Six lots tested across three independent laboratories measured 99.375% to 99.946% purity.
- Current-batch certificates can be verified directly with the issuing laboratory.
What does GLP-3RT mean?
It was a catalogue label, not a chemical name. No naming authority — IUPAC, CAS, or WHO — issues designations in that form.
That is why it appears inconsistently across sources: GLP-3RT, GLP3RT, GLP-3 RT, GLP 3RT. A label that exists only in catalogues can be spelled several ways, retired, or reused. None of that tells you anything about the molecule.
The “GLP” portion refers to the glucagon-like peptide receptor family, the receptor class this molecule interacts with in preclinical systems. It is a family reference rather than a structural description, and several structurally distinct peptides reference the same family.
How can I confirm what it refers to?
Use the CAS number. CAS 2381089-83-2 resolves to exactly one substance, and you can check it without relying on any supplier’s description.
- Look up the CAS number in a public registry. The PubChem entry gives the canonical structure, formula and mass.
- Compare the molecular formula against the specification below. A formula mismatch is the fastest way to detect that two listings are not the same substance.
- Read the lot certificate. A COA ties one physical lot to its measured purity and identity. A catalogue name cannot do that.
Product names are marketing artefacts. CAS numbers are not. When a listing name changes, as this one did, the registry number is the continuity between the old reference and the current one.
Specifications
| Property | Value |
|---|---|
| Current listing name | GLP-3 |
| Retired listing name | GLP-3RT |
| CAS registry number | 2381089-83-2 |
| Molecular formula | C221H342N46O68 |
| Molar mass | 4731.3 g/mol |
| Physical form | Lyophilised powder |
| Appearance | White to off-white solid |
| Purity specification | ≥99% by HPLC |
| Documentation | Lot-specific third-party COA |
The 4731.3 g/mol figure matters for molar calculations from a listed milligram quantity. Assuming a smaller mass introduces substantial error.
Measured purity across six lots
Most suppliers publish a purity specification. The table below is measured data — every lot analysed to date, including older batches, with the laboratory that performed the work.
| Lot | Size | Purity | Laboratory | Method | Report date |
|---|---|---|---|---|---|
| FO912 | 12 mg | 99.72% | ILS Laboratories | Full QC panel | 19 Jul 2026 |
| FO924 | 24 mg | 99.62% | ILS Laboratories | Full QC panel | 19 Jul 2026 |
| 36186 | 30 mg | 99.375% | Chromate | RP-HPLC with UV | 17 Jun 2026 |
| 34208 | 10 mg | 99.946% | Chromate | RP-HPLC with UV | 25 Apr 2026 |
| R10312 | 10 mg | 99.904% | Freedom Diagnostics | HPLC-UV / mass spec | 15 Mar 2026 |
| R20312 | 20 mg | 99.894% | Freedom Diagnostics | HPLC-UV / mass spec | 15 Mar 2026 |
Range: 99.375% to 99.946%, across three laboratories over five months.
Two things are worth drawing out. First, the spread is real and we publish it rather than quoting only the best number — lot 36186 at 99.375% is the lowest and is shown alongside the highest. Second, three different laboratories using different methods produced results within roughly half a percentage point of one another, which is a stronger identity signal than any single report.
Of the three, ILS Laboratories states ISO/IEC 17025 accreditation. That is worth checking on any certificate from any supplier. An accredited laboratory’s report and an unaccredited one’s are not equivalent evidence, however similar the documents look.
What does the full QC panel cover?
The two current lots were analysed under a full QC panel rather than purity alone. Heavy metals, for lot FO912:
| Element | Specification | Result |
|---|---|---|
| Arsenic (As) | NMT 1.5 ppm | Not detected |
| Cadmium (Cd) | NMT 0.5 ppm | 0.265 ppm |
| Lead (Pb) | NMT 1.0 ppm | Not detected |
| Mercury (Hg) | NMT 1.5 ppm | Not detected |
| Chromium (Cr) | NMT 10.0 ppm | 0.892 ppm |
The same panel reported identity confirmed by mass spectrometry, net content 12.73 mg against a 12 mg label, sterility recorded as no growth, endotoxin at NMT 0.05 EU/mL, and a fentanyl screen returning not detected.
These are analytical panel results, reported as measured. They describe the material’s composition and nothing else.
Can the certificates be verified independently?
Yes, for the current ILS-tested lots. Each carries an access code that resolves on the laboratory’s own portal, not on this site — for lot FO912, certificate COA-2026-XSTJNR, access code KW9EAGFZ, verifiable at ILS Laboratories’ verification portal.
That distinction matters. A PDF hosted by a supplier is a document the supplier controls. A record you can pull from the issuing laboratory is not. When evaluating any supplier in this category, independent verification is the question worth asking.
How should it be stored and handled?
Standard laboratory practice for lyophilised synthetic peptides:
- Storage. Sealed vials at −20°C, protected from light and moisture. Lyophilised material is substantially more stable than solution.
- Temperature excursions. Brief ambient exposure in transit is normal for lyophilised material. Return vials to −20°C on arrival.
- Freeze-thaw. Repeated freeze-thaw cycles degrade peptides, which is why storage stability and handling frequency are reported separately on a certificate.
- Traceability. Keep the lot number with the material. Lot number is what ties a vial back to its certificate, and material separated from its lot number cannot be traced to any analysis.
Specifics beyond this depend on your assay and your institution’s standard operating procedures, which take precedence over any supplier guidance.
Common questions
Is GLP-3RT the same as GLP-3?
Yes. GLP-3RT is a retired listing name for the material now listed as GLP-3. Both refer to CAS 2381089-83-2. The listing name changed; the substance specification did not.
What is the molecular formula?
C221H342N46O68, molar mass 4731.3 g/mol. The formula is frequently transcribed incorrectly in secondary sources. Confirm it against a registry entry for CAS 2381089-83-2.
What purity should I expect?
Six lots measured 99.375% to 99.946% across three laboratories. The specification is ≥99% by HPLC. Every lot ships with its own certificate; check the lot number on the vial against the certificate rather than relying on a published range.
How do I verify what I received?
Check three things against each other: the CAS number on the label, the formula on the certificate, and the mass-spectrometry result in that certificate. The lot number on the vial must match the certificate. For ILS-tested lots, the access code can be checked on the laboratory’s portal.
Can this be used outside a laboratory?
No. This material is supplied for in-vitro and laboratory research by qualified researchers and for no other purpose. It is not a drug, not a supplement, and not for human or veterinary use.
Research use only. Nothing on this page describes or implies use in humans or animals.