Vendor dossier · Changzhou, Jiangsu
SinoPep Biotechnology (Changzhou) Co., Ltd.
A Changzhou peptide house that has run its own solid-phase lines since 2011, and prints on every certificate the one number most of this directory leaves out.
Journal grade · ranked 25 of 28
798 reader reports
on the record
SNP is a synthesis house rather than a company that buys material finished and applies a label to it, and the file settles that question in the ordinary way — by asking about the chemistry and getting answers from somebody who runs it. What distinguishes the file is narrower and, in the desk’s view, more consequential than the manufacturing claim. Every certificate on it quantifies counter-ion content. Trifluoroacetate is reported as a figure with units, unprompted, alongside the purity determination. A chromatographic purity figure describes the composition of what eluted from the column; it does not describe the mass of peptide in the vial, and on a TFA salt the gap between the two is several per cent. Nine determinations out of nine carry the figure. Across the rest of this directory the desk records it on rather fewer than half.
Storefront The company sells directly at sinopep.net. Visit SinoPep → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.
The record
Nine independent purity determinations, mean 98.7%, range 98.2 to 99.2%, every result at or above the figure printed on the accompanying certificate. Method reference, gradient, column identifier and detection wavelength are present on all nine documents without a supplementary request, and the related-substances table is itemised by impurity with assigned retention times rather than reported as a single total.
One determination on the file does work that none of the others can. A catalogue line purchased in June 2025 was purchased again in May 2026 and both lots were determined on the same declared method; the results are a tenth of a percentage point apart. Reproducibility across a year is the question a single impressive figure cannot address, and the desk is able to put it to four suppliers in this directory. This is one of them.
Two limits hold the grade at A- rather than higher, and neither concerns the material. The determinations cover five compounds out of more than three hundred and fifty listed, which is a narrow base from which to generalise about a catalogue. And the quotation desk runs at two speeds: catalogue enquiries are answered the same working day, non-catalogue sequences take about three, recorded independently by four correspondents. The desk records the disparity because purchasers plan the second on the timings of the first and are then surprised.
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 independent purity determinations, mean 98.7% (range 98.2 to 99.2%), every one at or above the figure on the accompanying certificate.
- Counter-ion content quantified as trifluoroacetate, with units, on 9 of 9 certificates without a supplementary request.
- Method, gradient, column and wavelength present on 9 of 9 certificates; water by Karl Fischer and appearance on 9 of 9.
- 2011 incorporation in Changzhou consistent with registry records; the trading name on the invoice matches the name on the certificate on 9 of 9 orders.
- One catalogue line determined twice at an eleven-month interval on the same declared method, results 0.1 percentage points apart.
Ordering: lead times, minimums and what to ask for
- Lead time: catalogue lines dispatch within two working days of cleared payment; median door-to-door transit eight days to a European address against a quoted seven to ten.
- Quotation turnaround: same working day on catalogue enquiries; about three working days on non-catalogue sequences, recorded independently by four correspondents.
- Minimum quantity: single vials on the research catalogue; raw-material quantities quoted in writing against a written schedule before the order is taken.
- The certificate carries method reference, gradient, column, wavelength, batch, itemised related substances, counter-ion content, water by Karl Fischer and appearance, with release signed and dated.
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 | PeptideMeter | Retatrutide 5 mg | 97.5% | 98.2% | not tested |
| 2026-01 | PeptideMeter | Tirzepatide 20 mg | 98.2% | 98.6% | 100% |
| 2025-11 | VendorInvestigate | Semaglutide 15 mg | 98.2% | 98.5% | not tested |
| 2025-07 | PeptideMeter | Retatrutide 20 mg | 98.9% | 99.2% | not tested |
| 2025-03 | PeptideMeter | Semaglutide 2 mg | 98.2% | 99.1% | not tested |
| 2024-11 | Medutest | Tirzepatide 2 mg | 97.7% | 98.5% | 96% |
| 2024-08 | Medutest | Tesamorelin 5 mg | 98.4% | 98.9% | not tested |
| 2024-06 | Medutest | Tesamorelin 15 mg | 98.2% | 98.9% | not tested |
| 2024-03 | Janoshik | Tesamorelin 15 mg | 97.5% | 98.4% | 99% |
| 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 8 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 |
|---|---|---|
| 2026-05 | 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 | Requested the specification against which a lot is released | Answered in full within 4 working days; specification sent, with the tighter internal limit noted |
| 2025-08 | Asked which catalogue items are synthesised in-house | Answered in full within 2 working days; the in-house list was itemised |
| 2025-05 | Requested a batch record for a specific lot | Answered in full; the batch record was sent against the certificate reference |
| 2025-01 | Asked what lead time applies outside the stocked lines | Answered in full; a synthesis window was quoted per sequence length, in writing |
| 2024-10 | Requested the counter-ion form and residual solvent data | Answered in full; counter-ion stated as the acetate salt, with residual solvent figures attached |
| 2024-06 | Requested the reference-standard lot number behind a purity figure | Answered in full; the reference-standard lot was quoted and matched the supplier of the standard |
| 2024-02 | Asked for the name and location of the synthesis facility | Answered in full within 4 working days; site named, with the province and the line |
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.
The counter-ion figure is on the certificate, with units, and I did not have to ask for it. On a ten-milligram vial that number is worth more to me than a decimal place of area percent. I have no relationship with this supplier beyond having paid them.
Method reference, gradient and wavelength printed beside the purity figure. A purity value without its method is not a measurement and I have stopped pretending otherwise.
Submitted a vial to Janoshik without disclosing its origin. The independent figure came back above the declared one. The direction is the part that matters.
I repurchased the same line eleven months after the first order specifically to test for drift. Same declared method, results a tenth of a point apart. That comparison is almost never available.
Content is reported separately from chromatographic purity. Two distinct quantities, correctly distinguished, which sounds like a floor and is not.
Related substances itemised by impurity with retention times, not aggregated. One impurity and twelve impurities are not the same finding and a total conceals which you are holding.
Requested a chromatogram for a lot dispatched fourteen months earlier. It arrived the next working day, unquestioned.
Eleven vials from one consignment weighed against declared fill, all within two per cent. Fill uniformity is harder to achieve than purity and receives a fraction of the attention.
No adverse finding on material. A written quotation for a non-catalogue sequence took three working days where catalogue enquiries were answered the same afternoon; I planned badly around the difference.
Water content and appearance carried on the document as issued rather than released on request. Trivial determinations, and reliably diagnostic of the operation behind them.
Asked which resin a line was assembled on and received an answer rather than a referral to a sales function.
Transit from Changzhou was scanned continuously. Unscanned intervals are the failure mode that makes a transit estimate meaningless and there were none.
Five lots of one line across ten months, purity band under a point wide. Consistency is what I am buying; the best single figure in a file tells me very little.
Certificate, vial and invoice carried the same lot identifier across three consecutive orders.
Independent determination through Medutest agreed with the declared figure within the combined uncertainty of the two methods, which is the correct standard and not the same as an identical number.
The printed lot identifier on the unit is small enough that I photograph the carton on receipt. A minor operational irritation rather than a defect.
They quoted a sequence two other suppliers declined to respond about, with a purity target and a schedule, and both held.
Peptide content by weight was supplied on request with the method named. I would prefer it on the certificate as standard.
Regional stock was confirmed in writing before I ordered and the lane quoted matched the lane delivered.
Three orders, no variance in documentation between them. Nothing remarkable occurred, which is the finding.
The counter-ion line changed my dose arithmetic by more than the purity line did. I had not appreciated that before this file.
Not affiliated with the supplier. Two purchases, one independent determination, both unremarkable. Filed because the record was thin when I was deciding.
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 sinopep.net. Visit SinoPep → — a labelled, nofollowed link the Journal is paid nothing for. Read the record before you use it.
SinoPep Biotechnology (Changzhou) 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.