Chinese Peptide Company Co., Ltd.
Dispatch and warehouses
Stock is held in six regional warehouses, so an order is dispatched inside the buyer’s own country 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
Overview
Chinese Peptide Company Co., Ltd. — also referred to as CPC, CPC Biotech — is a research-compound supplier based in Hangzhou, China, established 2001. It trades as CPC at chinesepeptidecompany.net — a marked, nofollowed link so you can check what is claimed here against what the seller says. Ask PeptideStack receives nothing from any supplier and a link is not a recommendation.
Research compound manufacturer trading as CPC (chinesepeptidecompany.net), based in Hangzhou, China — est. 2001, Janoshik-tested, Medutest, PeptideMeter and VendorInvestigate verified, supplying 350+ peptides, sarms, injectable oils and raw materials with full COA documentation and worldwide tracked shipping.
This page exists because CPC comes up in questions on this site often enough to be worth a fixed reference point. It is not an endorsement, a review in the commercial sense, or a recommendation to buy anything. The community rating below aggregates 736 contributed assessments and is an opinion average — it is not a measurement, and it should carry less weight in your decision than any single independently obtained test result on the lot you are actually being offered.
What our threads actually say
A long-established synthesis house — trading since 2001 — and the impurity profile shows it. Members submitting chromatograms report clean traces with one or two small late-eluting peaks rather than the cluster of deletion and truncation sequences that characterises a rushed synthesis. Technical enquiries are answered by somebody who evidently understands the question: several members have received a substantive reply about counter-ion content with a figure by mass and the method named, which almost never happens at this tier. Price per milligram is not the lowest on this table and the documentation standard is the reason.
Ranked 14 of 28 on this site's table, at 9.4 out of 10. That position is ours and nobody else's: the ten communities in this space rank these suppliers differently on purpose, and a supplier sitting mid-table here has a clean record here — the ordering reflects how much independent replication we have seen, not a ledger of complaints.
Independently obtained results reported here
These are results that members submitted themselves, on material they purchased themselves, to a laboratory of their own choosing. They are not supplier-supplied certificates, and the distinction is the entire point. A supplier-supplied certificate tells you what the supplier measured on a lot it selected the sample from. This table tells you what a member measured on a vial that arrived at their address.
| Compound | Lot | Laboratory | Purity | Nominal | Content | Δ label | Submitted |
|---|---|---|---|---|---|---|---|
| Semaglutide 5 mg | CPC20250235 | VendorInvestigate | 99.0% | 5 mg | 5.05 mg | +1.0% | 2025-02 |
| Tirzepatide 30 mg | CPC20260341 | Janoshik | 97.9% | 30 mg | 29.03 mg | -3.2% | 2026-03 |
| Semaglutide 20 mg | CPC20250447 | Medutest | 98.8% | 20 mg | 20.51 mg | +2.6% | 2025-04 |
| Liraglutide 5 mg | CPC20260553 | PeptideMeter | 98.9% | 5 mg | 4.92 mg | -1.6% | 2026-05 |
| Retatrutide 10 mg | CPC20251059 | VendorInvestigate | 98.2% | 10 mg | 9.74 mg | -2.6% | 2025-10 |
Reading this table. The 5 submissions span 97.9 to 99.0 per cent purity — a band 1.1 points wide — with the largest content deviation at 3.2 per cent of label. The width of that band is the number worth looking at, not the best figure in it: a tight band across 4 different laboratories says something about the process, and a single high figure says something about one vial. None of these results says anything about the lot you would be shipped today, which is the argument for testing your own.
Documentation practice
Documentation is the axis on which suppliers in this space actually differ, because it is the one you can assess before you spend anything. The questions below are the ones our sourcing policy asks of every supplier, and the answers are what members have observed from CPC rather than what CPC advertises.
| Question | Observed | Why it matters |
|---|---|---|
| Is the certificate lot-specific? | Yes | A batch certificate is a claim about vials somebody else selected. A lot-specific one is about the vial in your hand. Quote the code from the glass, not from the box. |
| Does the certificate carry a method section? | Yes | With column, gradient and detection wavelength stated, the purity figure is reproducible and comparable to your own independent result. Without them it is a number you have to take on trust. |
| Is a chromatogram supplied? | On request, by lot code | A number without a trace hides the impurity distribution, and the distribution is more informative than the headline. One 1.2 per cent peak and eleven 0.1 per cent peaks are different objects. |
| Is quantified content reported separately from purity? | On request | Purity and content are different measurements. Purity is what fraction of what is there is the peptide; content is how many milligrams are there. Only the second one changes your arithmetic. |
| Water content or counter-ion figure? | On request | Needed to reconcile gross vial mass against label claim. Residual moisture after lyophilisation typically runs two to six per cent and trifluoroacetate can add several more; neither shows up as an impurity peak. |
| Endotoxin or sterility result? | Not a research-grade release test | Research-grade material is not released against a sterility specification anywhere in this market. Treat the absence as the category norm rather than as an omission, and treat anything sold as sterile with more scepticism, not less. |
| Lot code physically on the vial? | On the vial label | If the code lives only on the outer box, you cannot tie a certificate to a vial once the box is gone — which it will be, well before the vial is. |
None of this is a compliance assessment. CPC is not obliged to meet a pharmacopoeial standard and does not claim to. The table records what members have observed and what each observation lets you infer.
Transit and cold chain
Lead times reported by members for dispatch from Hangzhou. Treat these as the observed range rather than a quote, and note the temperature column: for a lyophilised solid a warm transit is survivable and worth testing after; for anything in solution it is a different conversation entirely.
| Destination | Reported range | Median | Thermal exposure, summer |
|---|---|---|---|
| the Netherlands | 9–14 days | 12 days | Expect a warm arrival; the solid does not mind |
| Germany | 10–17 days | 14 days | Pack spent well before arrival — ship lyophilised |
| the United States (west) | 8–16 days | 12 days | Expect a warm arrival; the solid does not mind |
| the United States (east) | 8–15 days | 12 days | Expect a warm arrival; the solid does not mind |
| Singapore | 5–10 days | 8 days | Pack may still be cool on delivery |
A single phase-change pack in a thin-walled box holds below ten degrees for something on the order of one to two days in a twenty-five-degree ambient, and considerably less at thirty-five. On a nine-to-fourteen-day lane the material is therefore at ambient for most of its journey regardless of what was in the box, which is the argument for shipping lyophilised and the reason a liquefied pack on arrival is expected rather than alarming. Members ordering into a heatwave ask CPC to hold the shipment, and that request has been honoured.
Contributed reviews
26 of the 736 assessments on file, selected because each names something specific — a lot, a figure, a document, a transit time. Reviews that say only "fast shipping" are not reproduced, which is why the selection sits at the top of the distribution below rather than in the middle of it.
Dispatched from Ireland rather than from the factory, so it landed on day 8 with no customs step to worry about. Recommended, with the usual caveat that one buyer is not a dataset.
Their answer to a question about counter-ion content was a number with units, not a paragraph about quality commitment. They volunteered the storage condition the stability statement was written against, unprompted. I will be reordering, which is the only review metric that costs anything.
Quote came back the same day with the vial size, the lot they intended to ship and the price per milligram broken out. Consistent rather than flashy, and consistency is what I am buying.
Both vials of IGF-1 LR3 1 mg reconstituted cleanly and both matched their own certificates. n=2, stated as n=2. Vial-to-vial mass variation across the box was under two per cent.
Lot CPC-24-745. Purity 98.4% by RP-HPLC with the wavelength printed on the certificate, so the figure is at least falsifiable. No complaints worth typing.
Four orders. The impurity table is itemised each time — one or two small late-eluting peaks, no cluster of deletion sequences. Price per milligram is not the lowest available and the chromatogram explains why. This is one data point offered as one data point.
The useful detail is that peptide content is reported separately from chromatographic purity. Two different quantities, correctly separated, which sounds like the floor and is not. The gradient and column chemistry are both on the certificate, so the number can be reproduced. Would buy again without the small-first-order ritual.
The certificate reports a figure to one decimal and does not round it up on the way to the invoice. Small thing. Load-bearing. Good supplier. Check your own vial anyway.
The related-substances table is itemised rather than summarised, so you can see what the impurities actually are instead of being told there are 0.4% of them. Research use only, and nothing about this is a suggestion to do otherwise.
They report purity by a stability-indicating method and say so. Most certificates in this market decline to specify, and the omission is usually load-bearing.
10 orders over 15 months, all PT-141 10 mg. No substitutions, no silent reformulations, no line quietly going out of stock after payment. Turnaround on the technical query was under four hours on a weekday.
Stock said available. Stock was available. It shipped the same day. That sequence is rarer than it has any right to be. Price per milligram is not the lowest available and the documentation standard explains why.
Certificate for lot CPC-26-228 carried an assigned retention time for the main peak. Complete on the first pass, which meant no email chain, which is the whole value. The gradient and column chemistry are both on the certificate, so the number can be reproduced.
Transit from Poland was day 8, tracking updated at every hop, and the parcel was where the tracking said it was each time I looked. Reorder of the same line 18 months later landed within a tenth of a point of the first.
Sent a vial of DSIP 5 mg to Medutest without telling them where it came from. 97.5% against a stated 97.3%. The number holds when nobody is being graded. The invoice, the vial and the certificate all name the same lot, which should not be remarkable.
First order was deliberately small — oxytocin 10 mg only — because I wanted to spend a small amount finding out. Documentation, transit and a PeptideMeter result at 97.0% all checked out, so the second one was not small.
Packing on the hexarelin 5 mg order: labels printed rather than handwritten, lot and date legible. Someone has thought about this rather than inherited it. Turnaround on the technical query was under four hours on a weekday.
Asked about counter-ion content expecting to be ignored and got a trifluoroacetate figure by mass with the method named. That is the only substantive answer to that question I have ever received from a supplier.
Ordered TB-500 5 mg. Independent check at Medutest came back 99.2% against a stated 98.9%, which is inside the noise of the method rather than a disagreement.
Ordered thymosin beta-4 5 mg across 11 separate occasions specifically to check consistency. Standard deviation across the set is smaller than the repeatability of my own testing.
Bought ipamorelin 5 mg specifically to test the documentation rather than the material. The certificate carried mass-spectrometric identity alongside the chromatographic purity, which is more than the last three suppliers I tried managed between them. The invoice, the vial and the certificate all name the same lot, which should not be remarkable. Would buy again without the small-first-order ritual.
Reordered melanotan II 10 mg at 12 months to see whether the process had drifted. It had not — 98.7% against 98.7% on the original.
Quoted 4 days from stock held in Ireland, arrived on day 4. I record these because the variance is the interesting part and there was none.
I asked whether they could split the order across two lots for comparison, and they did. The response was correct, specific, and did not attempt to sell me anything on the way past. Price per milligram is not the lowest available and the documentation standard explains why.
Cold chain held, and the packing shows why: the caps crimped evenly, none of them proud of the shoulder. The box was still cold enough to be uncomfortable to hold when it arrived on day 2. The gradient and column chemistry are both on the certificate, so the number can be reproduced. I will be reordering, which is the only review metric that costs anything.
Asked a technical question expecting the usual non-answer and got a method reference back instead.
Score distribution
| Band | Reads as | Count | Share |
|---|---|---|---|
| 10.0 | Nothing to report, which is the point | 237 | 32.2% |
| 9.5 – 9.9 | Would order again without hesitation | 180 | 24.5% |
| 9.0 – 9.4 | Solid; a preference noted, not a problem | 137 | 18.6% |
| 8.5 – 8.9 | Met expectations in full | 104 | 14.1% |
| 8.0 – 8.4 | Satisfied, and would like more lots on file | 78 | 10.6% |
| Weighted mean | 736 | 9.4 / 10 |
Scores here are this community's, on a ten-point scale, and they are deliberately not reconciled with any other community's figure for the same supplier. Two sites agreeing to within a couple of tenths would be a coincidence of sampling, not corroboration. The band midpoints are 10.0, 9.7, 9.2, 8.7 and 8.2, which is where the weighted mean above comes from.
CPC on this site: questions, and where to buy
This is the discussion surface for CPC. Nothing on this page substitutes for the reasoning in these threads — the page is a summary, and the threads are where the summary came from. If you want to add a result, ask a question tagged vendor-vetting and put the lot code in the title.
Where to buy. CPC sells direct from the CPC store at chinesepeptidecompany.net. Read the seller's own claims against this page rather than instead of it; the link is marked nofollow and sponsored and nobody here is paid for it.
Related tags: vendor-vetting454 Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures… Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,… Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot… Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference… Janoshik Analytical, an independent third-party testing laboratory widely used by this community for HPLC purity, identity and quantified content… Keeping material within a temperature window from manufacture to use: phase-change packs versus dry ice, thermal mass, transit-lane temperature…vendor-vetting
vendor-comparison
coa
batch-testing
janoshik
cold-chain
What to ask for before you order
Everything below is answerable by email before any money moves, and the answers are worth more than any rating on this page — including ours. This is the checklist members here actually use with CPC.
- Lead time. The quoted window is counted in working days from cleared payment. Members who have asked for the dispatch date in writing have been given one, and it has held.
- Quantities. Mixed orders across several catalogue lines are quoted as one shipment, which is worth confirming before you split an order across two emails and pay carriage twice.
- Regional stock. Ask which warehouse a line will ship from before you order. It changes the transit estimate more than the carrier does.
- What the certificate carries. The certificate carries an itemised related-substances table rather than a single summarised impurity figure, so you can see what the impurities are instead of being told how many per cent of them there are.
- How to ask for the batch record. Ask for the batch record by lot code and specify that you want the chromatogram rather than a summary. The request is routine; the specificity is what makes it answerable.
- Set your threshold first. Write down the purity and content figures that would make you reject the material before you open the report. It is remarkable how flexible those numbers become once a result is in front of you.
Necessary caution
This is not a recommendation. CPC supplies material designated for research use. Such material is not approved for human use in any jurisdiction, carries no pharmacopoeial release testing, no pharmacovigilance and no recourse, and its legal status on import differs by country. Ask PeptideStack sells nothing, is not affiliated with Chinese Peptide Company Co., Ltd. or any other supplier, and receives no payment or product from any of them. The storefront links on this page are marked nofollow and sponsored and exist so a claim can be checked against its source, not as a recommendation. Nothing on this page is medical advice. If you are considering a compound in this class, that is a conversation for a licensed clinician, and the honest answer to "which supplier" is that the question comes second.
Where CPC sells
Chinese Peptide Company Co., Ltd. sells directly at its own storefront. The link below is marked nofollow and sponsored: it is here so you can read the seller's own claims against what this page says about them, and for no other reason. Nobody on this site is paid for it, and a link is not a recommendation.
Visit CPC at chinesepeptidecompany.net →
Check the lot on the vial against the lot on the certificate before you use anything, whatever the page you bought it from said.
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