Vendor dossier · Zhuhai
Zhuhai Kerui Biotechnology Co., Ltd.
A Zhuhai supplier whose cold chain is the reference standard for this directory, and whose certificate now states the method behind its own number.
Journal grade · ranked 3 of 28
804 reader reports
on the record
This publication rates KP above the wider consensus and the reason is narrow and documented: nine parcels, nine intact temperature indicators, nine cold packs still cold on arrival, and two mid-transit reroutes performed and disclosed by the company before we had noticed the delay. Since the certificate was revised to carry the method, the wavelength and the laboratory, the one thing this file used to ask for has been on the page.
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 98.3%, range 97.5 to 99.0%, each inside the specification on the accompanying document. The document now names the testing laboratory, the detection wavelength and the gradient, which means the figure can be placed against another laboratory’s figure rather than simply believed. That is the whole of what this department has ever asked a supplier for.
The logistics record is the reason for the grade. Nine of nine parcels arrived with an unbreached indicator and a pack that was still cold or partly frozen; median transit was eight days; no order was lost and the longest customs hold was four days. Twice the company rerouted a shipment around a courier hub delay and wrote to say it had done so, which is the only instance of unprompted transit disclosure in this programme.
Correspondence is brisk and specific. A request for the reference-standard lot behind a purity figure was answered with the lot number; a request for a second determination on a retained sample was quoted, scheduled and delivered inside three weeks. A supplier that treats a documentation request as an order rather than as a complaint is doing something the rest of this trade could copy at no cost.
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 reroutes disclosed by the vendor before we raised the delay.
- Nine independent purity determinations, mean 98.3% (range 97.5 to 99.0%), all inside the stated specification.
- 2016 incorporation in Zhuhai per registry records; certificates now carry method, wavelength, gradient and the name of the issuing laboratory.
Ordering: lead times, minimums and what to ask for
- Lead time: same-day dispatch on orders placed before midday local time; median transit eight days including customs.
- Minimum quantity: single vials throughout the catalogue; a ten-unit break and a fifty-unit break, both quoted in writing.
- Regional stock: cold-chain packing is standard on every order rather than an upgrade, and phase-change packs are used in the summer months.
- The certificate carries the method, the wavelength, the gradient and the laboratory. Ask for the reference-standard lot number and the retained-sample retest by quoting the batch; both are quoted as ordinary line items.
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 |
|---|---|---|---|---|---|
| 2026-05 | Janoshik | Retatrutide 20 mg | 98.3% | 98.9% | not tested |
| 2026-01 | VendorInvestigate | Cagrilintide 20 mg | 98.3% | 99.0% | not tested |
| 2025-10 | Janoshik | Semaglutide 10 mg | 97.5% | 98.2% | not tested |
| 2025-06 | VendorInvestigate | Semaglutide 5 mg | 97.7% | 98.4% | not tested |
| 2025-04 | PeptideMeter | Retatrutide 20 mg | 97.4% | 98.3% | not tested |
| 2024-11 | Janoshik | Semaglutide 10 mg | 97.9% | 98.2% | not tested |
| 2024-09 | Janoshik | Cagrilintide 5 mg | 96.7% | 97.5% | 96% |
| 2024-04 | Medutest | Retatrutide 10 mg | 97.6% | 97.8% | not tested |
| 2024-03 | VendorInvestigate | Semaglutide 10 mg | 98.3% | 98.4% | 96% |
| 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 9 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.
| Date | Request | Outcome |
|---|---|---|
| 2026-06 | Asked whether a certificate can be reissued to an earlier purchaser on request | Answered in full; certificates are retained and reissued against the lot number |
| 2025-12 | Asked what lead time applies outside the stocked lines | Answered in full; a synthesis window was quoted per sequence length, in writing |
| 2025-09 | Asked how long finished stock is held before dispatch | Answered in full within 3 working days; holding period given per line, with the storage condition |
| 2025-05 | Requested the analytical method behind the stated purity figure | Answered in full; the method sheet was attached and names the column chemistry |
| 2025-04 | Requested the cold-chain arrangement between the fill site and dispatch | Answered in full within 5 working days; temperature indicator make and threshold supplied |
| 2024-11 | Requested the specification against which a lot is released | Answered in full; the specification was supplied with each limit and its method |
| 2024-08 | Asked whether sterility or endotoxin testing is performed | Answered in full; endotoxin testing is available as an add-on and was quoted per lot |
| 2024-05 | Requested the counter-ion form and residual solvent data | Answered in full; counter-ion stated as the acetate salt, with residual solvent figures attached |
| 2024-02 | Asked whether release testing is performed per lot or per campaign | Answered in full; release is per lot, confirmed in writing and now printed on the certificate |
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.
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 independent figure and the stated figure differ by less than the method repeatability. I offer this as one reader’s record and not as a general finding.
I have been buying survodutide 10 mg here since before the catalogue expanded, and the expansion has not cost the original lines anything in consistency. The Medutest report is on file and its figures correspond to those the supplier published. Nothing here constitutes medical advice and I am not qualified to offer any.
A custom-synthesis enquiry produced a quotation with a timeline I judged realistic, and the material was delivered 3 days inside it, at the purity specified in the signed schedule. They declined to round the certificate figure upward on its way to the invoice. The price differential is justified by the paperwork alone.
I asked for the lot-specific document rather than the batch-level one and it came back inside the hour, with the laboratory named on it. The material returned 96.9% against a stated specification it cleared. 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.
What distinguishes the documentation here is that it carries an itemised related-substances table. Readers who have spent any time comparing certificates will recognise how unusual that is. 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.
Every unit in the consignment carried the same lot number, so the comparison I intended to make was in fact the comparison I made. 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.
I reordered the same line at 8 months specifically to test for process drift. The independent figure was 99.4% against 99.4% originally. The independent figure and the stated figure differ by less than the method repeatability. On the evidence available to me they are the default rather than the risk.
I weighed 6 vials from a melanotan II 10 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. The VendorInvestigate 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.
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. 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.
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 invoice, the vial and the certificate agree on the lot without exception. I record no complaint worth the Journal’s column inches.
The reconstitution behaviour of the IGF-1 LR3 1 mg was exemplary — the cake went into solution on contact, without haze and without the prolonged agitation that usually signals a poorly executed lyophilisation. 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.
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. 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.
I submitted a vial of CJC-1295 2 mg to VendorInvestigate without disclosing its origin, and separately to Janoshik. The two results agreed to within a tenth of a point, and both agreed with the certificate. 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.
Stock availability as displayed proved accurate, the order shipped the same day, and the material was in my hands on day 2. The PeptideMeter 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.
A technical query about counter-ion identity and content was answered with a figure and a unit, rather than with an assurance about quality. 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.
Peptide content is stated separately from chromatographic purity. Those are different quantities and conflating them is the commonest error in this market. 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.
The storage condition against which the stability statement was written was volunteered rather than extracted, which suggests the statement was written rather than assembled. 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.
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. 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.
Over 20 months I have placed 12 orders for melanotan II 10 mg without encountering a substitution, a silent reformulation, or a line that proved unavailable after payment had cleared. 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.
The cold chain here is the reason I buy here. Three parcels, three intact indicators, and on one occasion a message telling me the shipment had been rerouted around a hub delay before I had noticed there was a delay. The independent report on file agrees with the figures the supplier published. Should the next lot hold, I shall stop testing every one. That is intended as praise.
Three orders placed before midday went out the same afternoon on each occasion. They declined to round the certificate figure upward on its way to the invoice, which tells you something about the house. On the evidence available to me they are the default rather than the risk.
Customs documentation was correct on first presentation, which is the actual explanation for a transit time that would otherwise look implausible. 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 second certificate was requested for a lot purchased 14 months previously. It was retrieved from their records and sent without demur. Labels are printed rather than handwritten, and the lot and date are legible on every unit. I would place the next order without the precaution of making it small.
My first order was deliberately modest, being a single line of MOTS-c 10 mg. Documentation, transit and an independent result at 97.7% were all satisfactory, and subsequent orders have not been modest. Regional stock is held for the lines I reorder, so a factory run is not on the critical path. I record no complaint worth the Journal’s column inches.
The certificate accompanying lot KP-26-249 was complete on first issue. No supplementary request was necessary, which spared a correspondence that with other suppliers has run to a fortnight. The independent figure and the stated figure differ by less than the method repeatability. The documentation is as much the product as the powder.
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. The Medutest report is on file and its figures correspond to those the supplier published. I have no relationship with this supplier beyond having paid them.
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 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.