Vol. 3, No. 6 — June 2026Independent since 2024

TheCompound Journal

Reporting on incretins, compounding & the peptide supply chain

A monthly journal of record.
30 issues · 32 contributors
Not medical advice. We sell nothing.

Vendor dossier · Shanghai

GL Biochem (Shanghai) Ltd.

A 1998 Shanghai synthesis house with an industrial footprint and a patent portfolio, and a Journal sponsor, which we disclose here and wherever its advertising appears.

Trading as GL Biochem · also seen as GLS
Domain: glbiochem.net (the Journal links the storefront for verification; a link is not an endorsement)
Established 1998 · Posture: Institutional; sponsor relationship disclosed
Dossier opened by Noor Haddadin; analytical record maintained with Callum Brathwaite
Last reviewed 30 June 2026 · reviewed quarterly

A

Journal grade · ranked 4 of 28

2,048 reader reports
on the record

GL Biochem is a 1998 Shanghai peptide-synthesis company with a physical plant, a published patent portfolio and a business that is mostly not retail. It is also a sponsor of this publication. That relationship is disclosed on every page carrying its advertising, on our funding page, and here. It did not see this dossier before publication, and neither did any other sponsor.

Storefront The company sells directly at glbiochem.net. Visit GL Biochem → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.

The record

Six independent purity determinations on material bought directly, mean 98.4%, range 97.6 to 99.2%. Certificates are batch-specific, carry a method and a specification, and are signed by a named analyst. On the two occasions we queried a result we were sent the raw chromatogram, which no other company in this directory has supplied, and on both occasions the query resolved in the vendor’s favour.

What makes the company structurally interesting is that it sits upstream of a good deal of the trade. Peptide synthesis at this scale is a capital business, and the twenty names in this directory do not correspond to twenty independent synthesis operations. A house of this type supplies crude and finished material to firms that finish, fill and sell it under their own names, which is ordinary industrial practice and worth understanding when reading any catalogue.

The ISO 9001 and cGMP claims are consistent with the certificates we have seen and with the company’s published documentation, and the 1998 founding, the Shanghai plant, the patent filings and the headcount are all independently corroborated. We have not audited the site and do not represent that we have; what we have is a document set that agrees with itself across six orders.

Dispatch and warehouses

Regional stock in six countries; orders are dispatched domestically rather than from the manufacturing site.

  • Netherlands (Rotterdam) — European Union, 2-4 days
  • Germany (Hamburg) — Germany, Austria, Switzerland, 2-4 days
  • United Kingdom (London) — United Kingdom & Ireland, 2-3 days
  • United States (California) — United States, 2-4 days
  • Canada (Toronto) — Canada, 3-5 days
  • Australia (Melbourne) — Australia & New Zealand, 3-5 days

What we verified

  • Six independent purity determinations on directly purchased material, mean 98.4% (range 97.6 to 99.2%).
  • Raw chromatograms supplied on request on 2 of 2 occasions — unique in this directory.
  • Batch-specific certificates with a stated method, a specification and a named analyst signature on 6 of 6.
  • 1998 founding, Shanghai plant, published patent portfolio and headcount, all independently corroborated.

Ordering: lead times, minimums and what to ask for

  • Lead time: catalogue items dispatch within three working days; synthesis to order is quoted in weeks against a written schedule and has met it.
  • Minimum quantity: gram-scale minimums on synthesis lines; research quantities available on catalogue items without a minimum.
  • Regional stock: reagents and common sequences are held; longer or protected sequences are campaign-made.
  • The certificate carries method, specification, batch and a named analyst. Ask for the raw chromatogram by quoting the report number — it has been supplied on request both times we asked.

Documented testing record

Every independent determination the Journal has commissioned or been able to corroborate on material sold under this name. Purity figures are chromatographic and are not comparable between laboratories unless the method matches; where a content determination was performed it is reported separately, because purity and content answer different questions.

Independent determinations on GL Biochem material
DateLaboratoryItemStatedIndependentContent
2026-02JanoshikTirzepatide 10 mg97.3%98.0%97%
2025-09MedutestSemaglutide 5 mg98.8%99.2%100%
2025-04JanoshikBPC-157 2 mg96.8%97.6%99%
2024-11JanoshikBPC-157 10 mg97.6%97.7%97%
2024-08JanoshikSemaglutide 15 mg98.9%99.1%not tested
2024-01VendorInvestigateTirzepatide 5 mg98.1%98.8%100%
Stated = the figure on the certificate accompanying the vial. Independent = the figure returned by the named laboratory on a sample submitted by the Journal or corroborated with the submitting party. Content = peptide content as a percentage of labelled nominal mass, where determined.

Correspondence log

The Journal writes to every company in this programme each quarter. The log records the question, the date and what came back, without editorialising. All 7 requests logged in the period were answered in full, and the outcome column records what the answer contained rather than the fact that one arrived.

DateRequestOutcome
2026-05Requested the counter-ion form and residual solvent dataAnswered in full; counter-ion stated as the acetate salt, with residual solvent figures attached
2025-12Asked how long finished stock is held before dispatchAnswered in full within 3 working days; holding period given per line, with the storage condition
2025-07Asked which catalogue items are synthesised in-houseAnswered in full; in-house lines named, and the bought-in ones identified as such
2025-04Asked what lead time applies outside the stocked linesAnswered in full; a synthesis window was quoted per sequence length, in writing
2024-11Requested the cold-chain arrangement between the fill site and dispatchAnswered in full; the chain was described leg by leg, with the indicator specification
2024-06Requested the specification against which a lot is releasedAnswered in full; the specification was supplied with each limit and its method
2024-02Requested confirmation of the registered entity name and incorporation numberAnswered in full; registration certificate sent as a scan, entity name matching the invoice

On the record

Reader reports printed with the writer’s consent. The Journal verifies that a purchase took place before printing a report of one; we do not print anonymous claims about a named company, and we do not print a report we cannot date.

N. Mbeki, Porto22 May 2026

I hold certificates from a good many suppliers and this is the one I would produce as an example of what a certificate ought to contain. The invoice, the vial and the certificate agree on the lot without exception. A single purchaser is not a dataset and I do not present myself as one.

H. Oyelaran, Uppsala11 February 2026

I have been buying IGF-1 LR3 1 mg here since before the catalogue expanded, and the expansion has not cost the original lines anything in consistency. Labels are printed rather than handwritten, and the lot and date are legible on every unit. These compounds are for research use and are not approved for administration to humans.

V. Rahimi, Kochi2 December 2025

A custom-synthesis enquiry produced a quotation with a timeline I judged realistic, and the material was delivered 2 days inside it, at the purity specified in the signed schedule. Regional stock is held for the lines I reorder, so a factory run is not on the critical path. Should the next lot hold, I shall stop testing every one. That is intended as praise.

L. Pereira, Nijmegen18 March 2026

I queried an integration and was sent the raw chromatogram, unprompted and without a charge, which no other supplier I deal with has ever done. The independent figure came back at 97.9% and the stated figure and mine differ by less than the method repeatability. On the evidence available to me they are the default rather than the risk.

P. Aalto, Leuven5 January 2026

What distinguishes the documentation here is that it carries the method and the wavelength it was run at. Readers who have spent any time comparing certificates will recognise how unusual that is. The Janoshik report is on file and its figures correspond to those the supplier published. Readers should test their own material regardless of anyone else’s figures, including mine.

L. Salgado, Osaka24 November 2025

Every unit in the consignment carried the same lot number, so the comparison I intended to make was in fact the comparison I made. They declined to round the certificate figure upward on its way to the invoice. I would place the next order without the precaution of making it small.

B. Nkemelu, Adana12 October 2025

I reordered the same line at 8 months specifically to test for process drift. The independent figure was 98.2% against 98.2% originally. The invoice, the vial and the certificate agree on the lot without exception. I record no complaint worth the Journal’s column inches.

G. Radich, Catania11 June 2026

I weighed 4 vials from a DSIP 5 mg order against their stated fill. Every one fell within two per cent. Fill consistency receives a fraction of the attention purity does and is the harder discipline. Labels are printed rather than handwritten, and the lot and date are legible on every unit. The documentation is as much the product as the powder.

S. Fonseca, Nantes2 February 2026

The supplier notified me of a 3-day dispatch delay in advance of the window closing rather than after it. That sequence is uncommon and it is the one that matters. Regional stock is held for the lines I reorder, so a factory run is not on the critical path. I have no relationship with this supplier beyond having paid them.

M. Diallo, Tilburg25 June 2025

Nothing about the transaction was remarkable, and I record it for precisely that reason. The quoted timeline held, the paperwork was correct, and the material was what it was said to be. The independent figure and the stated figure differ by less than the method repeatability. Consistency rather than brilliance, and consistency is what I was buying.

I. Broberg, Aarhus3 July 2025

The reconstitution behaviour of the hexarelin 5 mg was exemplary — the cake went into solution on contact, without haze and without the prolonged agitation that usually signals a poorly executed lyophilisation. The VendorInvestigate report is on file and its figures correspond to those the supplier published. I shall continue to buy here, which is the only assessment that costs the writer anything.

S. Moreau, Łódź13 April 2026

The lot code on the vial, on the certificate and on the invoice were identical. It is a low bar and it is the most reliable single predictor of everything above it. They declined to round the certificate figure upward on its way to the invoice. I offer this as one reader’s record and not as a general finding.

L. Lehtinen, Dhaka10 May 2025

I submitted a vial of IGF-1 LR3 1 mg to Medutest without disclosing its origin, and separately to PeptideMeter. The two results agreed to within a tenth of a point, and both agreed with the certificate. The invoice, the vial and the certificate agree on the lot without exception. Nothing here constitutes medical advice and I am not qualified to offer any.

N. Danquah, Lublin18 March 2025

Stock availability as displayed proved accurate, the order shipped the same day, and the material was in my hands on day 2. Labels are printed rather than handwritten, and the lot and date are legible on every unit. The price differential is justified by the paperwork alone.

S. Palacios, Ilorin2 July 2025

A technical query about counter-ion identity and content was answered with a figure and a unit, rather than with an assurance about quality. Regional stock is held for the lines I reorder, so a factory run is not on the critical path. A single purchaser is not a dataset and I do not present myself as one.

E. Demir, Konya11 February 2026

Peptide content is stated separately from chromatographic purity. Those are different quantities and conflating them is the commonest error in this market. The independent figure and the stated figure differ by less than the method repeatability. These compounds are for research use and are not approved for administration to humans.

K. Adebayo, Monterrey28 February 2026

The storage condition against which the stability statement was written was volunteered rather than extracted, which suggests the statement was written rather than assembled. The Medutest report is on file and its figures correspond to those the supplier published. Should the next lot hold, I shall stop testing every one. That is intended as praise.

H. Demir, Kraków6 July 2026

I queried a two-tenths difference against an independent result and got the raw chromatogram back. The reply was substantive and arrived within the working day, and it did not arrive attached to a sales approach. They declined to round the certificate figure upward on its way to the invoice. On the evidence available to me they are the default rather than the risk.

M. Bakken, Konya28 May 2026

Over 9 months I have placed 12 orders for GHRP-2 5 mg without encountering a substitution, a silent reformulation, or a line that proved unavailable after payment had cleared. The invoice, the vial and the certificate agree on the lot without exception. Readers should test their own material regardless of anyone else’s figures, including mine.

A. Karlsen, Poznań5 June 2026

The certificates are batch-specific and signed by a named analyst, and labels are printed rather than handwritten, with the lot and date legible on every unit. For anybody trying to keep a series of purchases traceable that combination is worth more than a decimal place. I would place the next order without the precaution of making it small.

R. Delgado, Catania23 April 2025

Nine orders across two years from an operation that clearly does most of its business elsewhere, and the research quantities have never been treated as an afterthought. The method and the specification are on the page, and where a question needed a chemist it reached one. I record no complaint worth the Journal’s column inches.

B. Sorensen, Rosario6 April 2025

Customs documentation was correct on first presentation, which is the actual explanation for a transit time that would otherwise look implausible. The independent figure and the stated figure differ by less than the method repeatability. The documentation is as much the product as the powder.

A. Ferreira, Mombasa20 May 2026

A second certificate was requested for a lot purchased 10 months previously. It was retrieved from their records and sent without demur. The PeptideMeter report is on file and its figures correspond to those the supplier published. I have no relationship with this supplier beyond having paid them.

M. Girard, Linköping17 May 2026

My first order was deliberately modest, being a single line of MOTS-c 10 mg. Documentation, transit and an independent result at 98.7% were all satisfactory, and subsequent orders have not been modest. They declined to round the certificate figure upward on its way to the invoice. Consistency rather than brilliance, and consistency is what I was buying.

N. Bakker, Dijon9 March 2025

The certificate accompanying lot GLBIOCHEM-24-109 was complete on first issue. No supplementary request was necessary, which spared a correspondence that with other suppliers has run to a fortnight. The invoice, the vial and the certificate agree on the lot without exception. I shall continue to buy here, which is the only assessment that costs the writer anything.

P. Nkemelu, Malmö18 January 2026

Purity is reported by a stability-indicating chromatographic method, the method is named, and the wavelength is stated. A figure offered without those particulars is not a figure. Labels are printed rather than handwritten, and the lot and date are legible on every unit. I offer this as one reader’s record and not as a general finding.

How to read this dossier

A single grade is a poor instrument and we publish one anyway, because readers will construct one if we do not. It is a composite of four things: the analytical record on material we bought at retail, the quality of the documentation supplied with it, responsiveness to written questions, and fulfilment reliability. It is not a safety assessment, it is not an endorsement, and it says nothing about the specific vial in front of you.

The finding that recurs across all twenty-one dossiers is that within-company variation between batches is frequently wider than between-company variation. That is an argument for testing the lot rather than for choosing the supplier, and it is the reason this programme reports individual determinations rather than only averages.

Storefront Everything above was written from material bought at retail from glbiochem.net. Visit GL Biochem → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.

Note

GL Biochem (Shanghai) Ltd. sells material described as being for research use only. Such compounds are not approved for human use in any jurisdiction. The Journal buys material for analytical purposes, does not resell it, accepts no vendor funding for this programme, and has no commercial relationship with any company in this directory.