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.

The synthesis house behind a great deal of material sold under other names — and a Journal sponsor, which we disclose here and on every page it appears.

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

B+

Journal grade · ranked 4 of 20

2,048 reader reports
on the record

GL Biochem is a 1998 Shanghai peptide-synthesis company with an industrial footprint, a large 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 has not seen this dossier before publication, and neither has 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 97.6–99.2%. 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 received the raw chromatogram, which no other company in this directory has supplied.

What makes GL Biochem structurally interesting is that it sits upstream of several other names in this directory. Multiple vendors we track describe themselves as manufacturers while sourcing crude or finished peptide from houses of this type. We have not been able to establish, for any specific vendor, that GL Biochem is the source — the paper trail stops at a trading company almost every time — but readers should understand that the twenty names in this directory do not correspond to twenty independent synthesis operations.

The ISO 9001 and cGMP claims are consistent with the certificates we have seen and with the company's published documentation. We have not audited the site and do not represent that we have.

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 97.6–99.2%).
  • 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.

What we could not verify

  • Whether GL Biochem is the upstream source for any specific vendor in this directory. Paper trails stop at trading companies.
  • ISO 9001 and cGMP status by direct audit — we rely on documentation, not inspection.
  • Sterility of research-grade material, which is not claimed for that grade.
  • How much of the retail-channel material sold under other names originates here.

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
2026-04VendorInvestigateCagrilintide 2 mg98.3%98.2%not tested
2026-04PeptideMeterRetatrutide 5 mg99.6%100.0%94%
2025-12VendorInvestigateSemaglutide 20 mg99.1%98.7%92%
2025-09JanoshikRetatrutide 15 mg97.5%97.4%not tested
2025-07JanoshikTirzepatide 15 mg98.4%97.9%not tested
2025-05MedutestTirzepatide 15 mg99.6%99.2%not tested
2024-11VendorInvestigateLiraglutide 2 mg98.9%98.4%not tested
2024-09MedutestSemaglutide 5 mg99.5%99.4%78%
2024-05PeptideMeterBPC-157 20 mg99.6%99.4%not tested
2024-04JanoshikTesamorelin 10 mg99.6%99.7%97%
2024-02PeptideMeterBPC-157 20 mg99.3%98.3%79%
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 the outcome, without editorialising. 4 of 6 logged requests received a full answer within the period.

DateRequestOutcome
2026-06Asked whether release testing is performed per lot or per campaignAnswered in full within 10 working days
2026-04Requested the reference-standard lot numberAnswered in full within 2 working days
2025-10Requested a batch record for a specific lotAnswered in full within 2 working days
2024-10Asked whether pre-change stock remained in distributionAnswered in full within 2 working days
2024-07Asked whether corrected certificates are reissued to earlier purchasersAnswered in part; the specific question was not addressed
2024-01Requested comment on an independent purity determination below the stated figureAnswered with a restatement of published quality claims

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

Dispatched from their warehouse in Canada rather than from the factory, so the glutathione 600 mg was with me on day 2.

H. Oyelaran, Uppsala11 February 2026

Everything about the order was routine in the best sense — quoted 3 days, arrived in 2.

V. Rahimi, Kochi2 December 2025

9 orders in eighteen months, no substitutions, no reformulations, everything in stock when the site said it was. Boring is the highest compliment I have.

L. Pereira, Nijmegen18 March 2026

Shipped from their warehouse in Germany, arrived day 4, documentation complete.

P. Aalto, Leuven5 January 2026

Regional stock makes the difference — dispatched within the Netherlands, day 3, cold pack still hard on arrival.

L. Salgado, Osaka24 November 2025

Consistent rather than flashy. Everything lands in the high nineties, and it lands there every time.

B. Nkemelu, Adana12 October 2025

Their warehouse in Australia had the thymosin alpha-1 5 mg in stock and it shipped the same afternoon. Tracking never left the country.

G. Radich, Catania11 June 2026

Every certificate I have from them is lot-specific. Not one batch-level document in 7 orders.

S. Fonseca, Nantes2 February 2026

Identity confirmed by mass spec on the certificate, not just an area-percent figure. Both questions answered on one page.

M. Diallo, Tilburg25 June 2025

Same lot documentation as the factory ships, but out of their warehouse in Canada, so it landed on day 3.

I. Broberg, Aarhus3 July 2025

The certificate for lot GLB-24-908 carried method, wavelength, water content and an itemised related-substances table. Complete on the first pass.

S. Moreau, Łódź13 April 2026

Tenth order from them, all LL-37 5 mg. Sent one vial from each to VendorInvestigate and the whole set landed inside half a point of each other. That flatness is exactly what I pay for.

L. Lehtinen, Dhaka10 May 2025

Arrived on day 2 against a quoted 3. Customs paperwork was right first time, which is why it moved that fast.

N. Danquah, Lublin18 March 2025

Third order and it went the same way as the first two. Predictable in the way you want a supplier to be.

S. Palacios, Ilorin2 July 2025

First order, deliberately small, BPC-157 10 mg only. Documentation, transit and a Janoshik result at 98.5% all checked out, so the next one will not be small.

E. Demir, Konya11 February 2026

Reliable on the general catalogue lines. Purity figures cluster tightly and the certificates match the lots.

K. Adebayo, Monterrey28 February 2026

Shipped with a stated storage recommendation and a shelf-life figure tied to it, without my asking.

H. Demir, Kraków6 July 2026

Asked them to hold an order until I confirmed a lot number and they did, without fuss and without a restocking charge.

M. Bakken, Konya28 May 2026

Fair pricing for the documentation standard, and delivery landed on day 4 as quoted.

A. Karlsen, Poznań5 June 2026

Solid on the IGF-1 LR3 1 mg. Purity where it should be, transit 4 days, paperwork in order.

R. Delgado, Catania23 April 2025

Good communication throughout, accurate lead time, and the parcel arrived on day 4.

B. Sorensen, Rosario6 April 2025

Sensible packing, sensible timelines, and a certificate that says what it should. No notes.

A. Ferreira, Mombasa20 May 2026

Straightforward order, arrived as described, documentation adequate and complete. Nothing to add, which is the point.

M. Girard, Linköping17 May 2026

Three compounds on one invoice, all three lot-matched to their own certificates, all three inside spec on independent testing.

N. Bakker, Dijon9 March 2025

Queried the related-substances total on lot GLB-26-390; they came back with method, column and detection limit. That depth is rare.

P. Nkemelu, Malmö18 January 2026

Reconstituted the KPV 10 mg and it went clear on contact — no haze, no floaters, no long swirl. Tells you the lyophilisation was done properly.

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 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.