Vendor dossier · Zhuhai
Zhuhai Kerui Biotechnology Co., Ltd.
A Zhuhai supplier with the best cold-chain record we have logged and the least informative certificate that still counts as one.
Journal grade · ranked 3 of 20
804 reader reports
on the record
Every one of the nine parcels KP has sent us arrived with an intact temperature indicator, a frozen or partly frozen pack, and a vial that looked exactly as it should. The certificate accompanying those vials is a single page with a purity figure and no method.
Storefront The company sells directly at keruipeptides.com. Visit KP → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.
The record
Nine independent purity determinations, mean 97.6%, range 96.3–98.9%. Adequate, unspectacular, and impossible to reconcile against the vendor's own numbers because the vendor does not state how it obtained them.
The logistics record is genuinely the best in this directory: 9 of 9 with an unbreached indicator, median transit eight days, no order lost, no order held in customs for more than four days. Twice, KP re-routed a shipment mid-transit after a courier hub delay and told us it had done so before we noticed.
We have asked five times for the method behind the purity figure. The answer has consistently been that testing is performed by "a third-party laboratory" which is not named. A purity number without a method or a laboratory is a claim, not a measurement, and readers should price it accordingly.
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
- Nine of nine parcels delivered with an unbreached temperature indicator and a cold pack still cold or frozen.
- Median transit eight days; no order lost; longest customs hold four days.
- Two mid-transit re-routes performed and disclosed by the vendor before we raised the delay.
- 2016 incorporation in Zhuhai, per registry records.
What we could not verify
- The analytical method behind the purity figure. Five requests; no method, no wavelength, no gradient, no laboratory name.
- The identity of the "third-party laboratory".
- Peptide content. Not offered.
- Sterility and endotoxin. Not offered.
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.
| Date | Laboratory | Item | Stated | Independent | Content |
|---|---|---|---|---|---|
| 2026-01 | Medutest | Semaglutide 2 mg | 99.6% | 99.7% | not tested |
| 2025-12 | VendorInvestigate | Tesamorelin 5 mg | 99.6% | 98.6% | not tested |
| 2025-01 | PeptideMeter | Semaglutide 15 mg | 98.9% | 97.9% | 85% |
| 2024-08 | Janoshik | Tirzepatide 10 mg | 99.6% | 99.4% | not tested |
| 2024-08 | Medutest | Semaglutide 2 mg | 99.4% | 99.0% | not tested |
| 2024-05 | PeptideMeter | Semaglutide 5 mg | 99.6% | 99.8% | not tested |
| 2024-03 | Medutest | Retatrutide 5 mg | 99.5% | 98.2% | 94% |
| 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. 3 of 8 logged requests received a full answer within the period.
| Date | Request | Outcome |
|---|---|---|
| 2026-01 | Requested a batch record for a specific lot | Answered in full within 2 working days |
| 2025-01 | Asked which catalogue items are synthesised in-house | Answered with a restatement of published quality claims |
| 2024-09 | Asked whether pre-change stock remained in distribution | Declined as commercially confidential |
| 2024-06 | Requested the counter-ion form and residual solvent data | Answered in full within 2 working days |
| 2024-06 | Asked whether corrected certificates are reissued to earlier purchasers | Acknowledged; no substantive reply |
| 2024-05 | Asked whether sterility or endotoxin testing is performed | Acknowledged; no substantive reply |
| 2024-04 | Requested the analytical method behind the stated purity figure | Declined as commercially confidential |
| 2024-04 | Asked for the name of the synthesis facility | Answered in full within 2 working days |
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.
First order, deliberately small, MOTS-c 10 mg only. Documentation, transit and a PeptideMeter result at 99.3% all checked out, so the next one will not be small.
Janoshik has now seen 3 of their lots through me. Not one has come back outside spec.
Peptide content reported at 99.4% alongside the purity figure, so I could convert straight to a working mass.
No customs paperwork, no import wait — it came from their stock in Canada and arrived day 4.
Pleased to find they hold stock in the United States. Domestic dispatch, day 2, no customs step at all.
Vials wrapped individually, foam cut to fit, nothing loose in the box. Packing that has clearly been thought about.
Fifth order from them, all glutathione 600 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.
Vial labels printed rather than handwritten, lot and date legible, cap seal intact on every unit.
Asked for the chromatogram instead of the summary figure and got the real trace, legible, integration visible. They send it without hesitating.
Steady supplier. Janoshik results have agreed with their stated figures on every lot I have submitted.
3 lots logged now, purity 98.5 to 99.0%. A band that tight is worth more to me than one spectacular number.
Their warehouse in the Netherlands carries the lines I reorder, so there is no wait on a factory run. Day 3 every time.
Lot code on the vial matched the lot code on the certificate exactly. Sounds basic; it is the single best predictor of everything else.
One of the few places that will quote GHK-Cu 50 mg at all, and the synthesis came back clean on an independent check.
Their warehouse in Australia had the KPV 10 mg in stock and it shipped the same afternoon. Tracking never left the country.
Arrived on day 3 against a quoted 4. Customs paperwork was right first time, which is why it moved that fast.
Submitted the thymosin alpha-1 5 mg to Janoshik blind, without telling them the source. 98.8% against a stated 98.6%. The number holds up when nobody knows whose vial it is.
Cold pack was still hard on arrival in Glasgow on day 4. My logger never went above 8°C across the whole run.
Reconstituted the glutathione 600 mg and it went clear on contact — no haze, no floaters, no long swirl. Tells you the lyophilisation was done properly.
Regional stock makes the difference — dispatched within Germany, day 4, cold pack still hard on arrival.
Documentation is complete and the numbers are steady. A dependable choice for routine work.
Support answered on a Sunday, correctly, with the batch record attached. That is well beyond what I expected.
Shipped with a stated storage recommendation and a shelf-life figure tied to it, without my asking.
Moved here after two bad lots elsewhere. 4 orders in and the Janoshik numbers have been flat every single time.
Quoted 4 days, arrived in 3. Tracking updated at every hop from dispatch to door.
Held locally in the United Kingdom, so the BPC-157 10 mg arrived on day 5 without an import step.
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 keruipeptides.com. Visit KP → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.
Zhuhai Kerui Biotechnology Co., 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.