Skip to main content

1 / 4

Image 1 of 4

Incretin & Amylin Analogues

GLP-3

GLP-3 is retatrutide, a synthetic lipidated peptide and, by receptor class, a GIP, GLP-1 and glucagon receptor agonist peptide. British Peptide Labs supplies GLP-3 in the UK as a lyophilised powder in sealed 10, 30 and 40 mg vials from £59, at ≥99% purity (HPLC), with independent third-party testing by PeptideVerify (HPLC + LC-MS).

In stock
Concentration
10 mg vial£59.00

£5.90 per mg

≥99% purity (HPLC) · Independent third-party testing by PeptideVerify · View report

Order before 3pm for same-day dispatch.

Cut-off 3pm, Mon–Sat

Free next-day tracked delivery on every order · Royal Mail Tracked 24

10 mg · £59.00 · £5.90/mg

Independent third-party testing by PeptideVerify

Report PV-82D8C6-XTFK · issued 6 August 2026 · HPLC-PDA and LC-MS

How to read this report
Download PDF

At a glance

Research area
Incretin & Amylin Analogues · Explore the research area
Presentations
10 mg, 20 mg, 30 mg and 40 mg
Form
Lyophilised powder in a sealed vial
Purity
≥99% (HPLC)
CAS number
2381089-83-2
Molecular formula
C221H342N46O68
Molecular weight
4731.4 g/mol
Dispatch
Order by 3pm Mon–Sat for same-day dispatch

About GLP-3

GLP-3 (retatrutide) is a synthetic lipidated peptide: a chain of amino acid residues with a lipid group covalently attached. By receptor class it is a GIP, GLP-1 and glucagon receptor agonist peptide, and it belongs to the Incretin & Amylin Analogues research area, alongside other lipidated peptide analogues.

The catalogue lists CAS number 2381089-83-2, the molecular formula C221H342N46O68 and a molecular weight of 4731.4 g/mol. The formula describes the whole conjugate, peptide chain and lipid group together, and at this mass the molecule sits between short synthetic peptides and small proteins. Its identity is confirmed by electrospray mass spectrometry, in which it appears as a series of multiply charged ions that are deconvoluted to a single neutral mass for comparison with the expected value, while reversed-phase HPLC gives the chromatographic profile. Each presentation is supplied as a lyophilised powder in a sealed vial.

Further reading

GLP-3 structure and analytical profile

The GLP-3 chain has thirty-nine residues, written in one-letter code as Y-Aib-QGTFTSDYSI-αMeL-LDKKAQ-Aib-AFIEYLLEGGPSSGAPPPS-NH2. It opens with a tyrosine that keeps a free N-terminal amine and closes with serine amide, Ser39-NH2, so the C-terminus carries no free carboxylic acid.

Three positions hold residues outside the twenty coded amino acids: α-aminoisobutyric acid (Aib) at positions 2 and 20, and α-methyl-L-leucine (αMeL) at position 13. Each has a methyl group on the α-carbon where a coded residue has a hydrogen, so Aib is 14 Da heavier than alanine and αMeL 14 Da heavier than leucine. Tandem mass spectrometry places all three from the fragment ions that contain them.

The chain holds three tyrosines, at positions 1, 10 and 25, two phenylalanines and no tryptophan, so its absorbance near 280 nm comes from the tyrosines while the peptide bonds give the stronger signal around 214 nm. Of its two lysines, Lys16 keeps a free side-chain amine and Lys17 carries the lipid group.

The side chain of lysine 17 is acylated with a C20 fatty diacid, joined through a γ-glutamic acid unit and one OEG spacer, a short ethylene-glycol-based amino acid. Read outward from the lysine, the group runs spacer, γ-glutamic acid, then the twenty-carbon chain ending in a free carboxylic acid. The formula C221H342N46O68 covers chain, linker and diacid as one molecule.

Structurally the diacid adds a long hydrocarbon segment to an otherwise polar chain, which is why GLP-3 elutes late in reversed-phase HPLC. Any chain missing the diacid, or carrying it on another lysine, shows a different retention time and a different mass, so the chromatogram and the mass spectrum check the attachment from two sides.

The monoisotopic mass is 4728.47 Da and the average molecular weight 4731.4 g/mol. The singly protonated ion, [M+H]+, is calculated at m/z 4729.48, but electrospray shows mainly multiply charged ions, such as [M+3H]3+ near m/z 1577.16 and [M+4H]4+ near m/z 1183.12, which are deconvoluted to one neutral mass. Reversed-phase HPLC with photodiode-array detection gives the purity as the main peak's share of total peak area.

The C-terminal segment from residue 30, Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2, is proline-rich. The two glutamines, Gln3 and Gln19, are the residues most able to deamidate, a shift of +0.98 Da that high-resolution mass spectrometry resolves from the main ion.

Our GLP-3 is covered by PeptideVerify report PV-82D8C6-XTFK, by HPLC-PDA and LC-MS, published on this page and in the COA Library. The material is a white to off-white lyophilised solid in a sealed vial. The sealed vial is stored at 2–8 °C short term, or at −20 °C and below for long-term storage, protected from light and away from repeated freeze-thaw cycles.

Buying GLP-3 in the UK

Order GLP-3 directly from British Peptide Labs, a UK-registered company, as a sealed vial in 10 mg, 20 mg, 30 mg and 40 mg presentations, from £59. Every size is listed below with its vial price and its price per mg, so the presentations compare at a glance.

GLP-3 price (UK)
PresentationPrice£/mg
GLP-3 10 mg£59.00£5.90
GLP-3 20 mgOut of stock£89.00£4.45
GLP-3 30 mg£110.00£3.67
GLP-3 40 mgBest value£145.00£3.63

Priced at £3.63/mg, below the UK median of £4.00/mg across 7 suppliers in the October 2026 UK Research Peptide Price Index.

Choose a presentation in the buy box, add it to your basket and check out. Orders placed before 3pm Mon–Sat are packed the same working day and handed to Royal Mail Tracked 24, and your tracking number is emailed as soon as the parcel leaves us. Larger orders are welcome: add as many vials as your laboratory needs in a single basket.

For what other UK suppliers charge, see our UK price per mg data, updated every month.

Product information

Synonym
retatrutide
CAS number
2381089-83-2
Molecular formula
C221H342N46O68
Molecular weight
4731.4 g/mol
Appearance
White to off-white lyophilised powder
Purity
≥99% (HPLC)
Net content
10 mg, 20 mg, 30 mg or 40 mg per vial
Storage (sealed vial)
Store at 2–8 °C short term, or at −20 °C and below for long-term storage. Protect from light and avoid repeated freeze-thaw cycles
Testing
Independent third-party testing by PeptideVerify (HPLC-PDA and LC-MS)
Certificate
PV-82D8C6-XTFK, issued 6 August 2026
Supplier
British Peptide Labs, trading name of AODAEMON LTD, UK-registered company (Companies House 17176945)
PubChem CID
171390338
Research use
For laboratory research use only. Not for human or veterinary use.

GLP-3 is retatrutide, a synthetic lipidated peptide and, by receptor class, a GIP, GLP-1 and glucagon receptor agonist peptide. British Peptide Labs supplies GLP-3 in the UK as a lyophilised powder in sealed 10, 30 and 40 mg vials from £59, at ≥99% purity (HPLC), with independent third-party testing by PeptideVerify (HPLC + LC-MS). Independent report by PeptideVerify (HPLC and LC-MS), published in the COA Library. Store the sealed vial at 2–8 °C for short-term storage, or at −20 °C and below for long term. Protect from light and avoid repeated freeze-thaw cycles. For research use only. Not for human or veterinary use. Sold strictly for in-vitro laboratory research; not for diagnosis or treatment.

Testing
Independent third-party testing by PeptideVerify (HPLC-PDA and LC-MS), published on this page and in the COA Library
Presentations covered
10 mg, 20 mg, 30 mg and 40 mg
Certificate of analysis
Report PV-82D8C6-XTFK — issued 6 August 2026

Packing
Each sealed vial travels in protective packing.
Dispatch
Orders placed before 3pm Mon–Sat leave the same day.
Delivery
Next-day tracked delivery with Royal Mail Tracked 24.
Tracking
Your tracking number is emailed as soon as the order is dispatched.
Delivery cost
Delivery is free on every order.
Shipping details

Questions about GLP-3

GLP-3 is retatrutide, a synthetic lipidated peptide and, by receptor class, a GIP, GLP-1 and glucagon receptor agonist peptide. It is supplied in a sealed vial as a white to off-white lyophilised powder, in 10 mg, 20 mg, 30 mg and 40 mg presentations.

Read the Learn article

Order GLP-3 directly from British Peptide Labs, a UK-registered company. It is supplied in sealed 10, 30 and 40 mg vials, from £59, at ≥99% purity (HPLC), with independent third-party testing by PeptideVerify. Orders placed before 3pm Mon–Sat are dispatched the same day by Royal Mail Tracked 24 for next-day tracked delivery.

Yes. GLP-3 is in stock in the 10 mg, 30 mg and 40 mg presentations, and orders placed before 3pm Mon–Sat leave the same working day.

GLP-3 is £59.00 for 10 mg, £110.00 for 30 mg and £145.00 for 40 mg at British Peptide Labs, from £5.90 down to £3.63 per mg, with free tracked delivery to any UK address.

GLP-3 (retatrutide) is listed under CAS 2381089-83-2, with the molecular formula C221H342N46O68 and a molecular weight of 4731.4 g/mol.

Yes. GLP-3 is ≥99% purity (HPLC), with independent third-party testing by PeptideVerify (HPLC-PDA and LC-MS). Report PV-82D8C6-XTFK, issued 6 August 2026, can be downloaded on this page and from the COA Library.

Open the COA Library

Store at 2–8 °C short term, or at −20 °C and below for long-term storage. Protect from light and avoid repeated freeze-thaw cycles.

Orders placed before 3pm Mon–Sat are packed the same working day and handed to Royal Mail Tracked 24. Delivery is free to any UK address, and Royal Mail Tracked 24 delivers the next working day after dispatch.

Shipping details

British Peptide Labs supplies GLP-3 to buyers aged 18 and over for in-vitro laboratory research, under our Terms and Conditions.

Read the Terms and Conditions

Y-Aib-QGTFTSDYSI-αMeL-LDKKAQ-Aib-AFIEYLLEGGPSSGAPPPS-NH2, read from the N-terminal tyrosine to the C-terminal serine amide. Aib and αMeL are written out because they have no one-letter code, and the lysine at position 17 carries the fatty diacid side chain.

4728.47 Da, against an average molecular weight of 4731.4 g/mol. The [M+H]+ ion is calculated at m/z 4729.48; in electrospray LC-MS the [M+3H]3+ ion near m/z 1577.16 and the [M+4H]4+ ion near m/z 1183.12 are the ones usually read and deconvoluted. The deconvoluted spectrum is read against the average figure, 4731.4 g/mol, because at this mass the monoisotopic peak is a small part of the isotope envelope.

Three: α-aminoisobutyric acid at positions 2 and 20, and α-methyl-L-leucine at position 13. Both are α,α-disubstituted amino acids, with a methyl group on the α-carbon in place of a hydrogen, and both are built in during solid-phase synthesis.

On the side-chain amine of lysine 17. A C20 fatty diacid is joined there through a γ-glutamic acid unit and one OEG spacer, while the N-terminal amine stays free and the C-terminus is an amide. The other lysine, Lys16, keeps a free side-chain amine, and the formula C221H342N46O68 counts the whole side chain.

GLP-3 is catalogued in the Incretin & Amylin Analogues research area, where compounds are grouped by molecular class. The research area page lists each of them with its identifiers.

Incretin & Amylin Analogues research area