PolyPeptide Group (Hangzhou) 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
PolyPeptide Group (Hangzhou) Co., Ltd. — also referred to as PPG, 多肽集团 — is a research-compound supplier based in Hangzhou, Zhejiang, China, established 2006. It trades as PPG at polypeptidegroup.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.
Solid-phase peptide synthesis house trading as PPG (polypeptidegroup.net), based in Hangzhou, Zhejiang, China — est. 2006, Janoshik-tested, Medutest, PeptideMeter and VendorInvestigate verified, supplying 350+ research compounds across peptides, sarms, injectable oils and raw materials with full COA documentation and worldwide tracked shipping.
This page exists because PPG 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 811 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 synthesis house rather than a trading company, and the file turns on one habit that almost nobody else in this table has: the chromatogram is printed on the certificate. The purity figure is not asserted at you, it is shown — the trace it was integrated from, the gradient table beside it, the column chemistry and the wavelength, so a reader who knows what a drifting baseline or a generously drawn integration limit looks like can check the number rather than accept it. Members here have used that. One asked whether a principal peak carried a shoulder and was sent the expanded region of the trace rather than an assurance; another pulled a supplementary certificate against a lot bought nineteen months earlier and got it back with the chromatogram intact, which tells you the underlying record was kept and not just the summary. Independently submitted results reported here run 97.8 to 98.3 across five lots on four separate laboratories and on none of them did the printed figure come out the higher number. Peptide content, water by Karl Fischer and counter-ion content are all on the document as separate figures with units, so working mass off the fill is arithmetic instead of assumption. Two things hold it where it sits rather than higher: the catalogue runs past 350 lines and the replication we hold is five lots deep, and a printed trace evidences the integration of the injection it depicts — it does not evidence that your vial came out of that injection. Hangzhou dispatch runs through Shanghai and members report continuous scanning on the lane rather than the dead intervals that make a transit estimate useless.
Ranked 12 of 28 on this site's table, at 9.5 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 |
|---|---|---|---|---|---|---|---|
| Tesamorelin 10 mg | PPG20250662 | VendorInvestigate | 98.2% | 10 mg | 10.00 mg | +0.0% | 2025-06 |
| BPC-157 10 mg | PPG20260768 | Janoshik | 98.3% | 10 mg | 10.26 mg | +2.6% | 2026-07 |
| Survodutide 10 mg | PPG20250874 | Medutest | 98.0% | 10 mg | 10.16 mg | +1.6% | 2025-08 |
| Cagrilintide 5 mg | PPG20260980 | PeptideMeter | 98.1% | 5 mg | 4.87 mg | -2.6% | 2026-09 |
| Semaglutide 5 mg | PPG20250286 | VendorInvestigate | 98.6% | 5 mg | 5.16 mg | +3.2% | 2025-02 |
Reading this table. The 5 submissions span 98.0 to 98.6 per cent purity — a band 0.6 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 PPG rather than what PPG 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 | 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. PPG 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) | 8–13 days | 11 days | Pack may still be cool on delivery |
| 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 PPG to hold the shipment, and that request has been honoured.
Contributed reviews
24 of the 811 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.
The certificate has the chromatogram printed on it. I can see where the integration marks were dropped and whether the baseline was drawn honestly. Everything else in my folder asks me to take the number on trust.
Gradient table and column chemistry sit beside the trace. That means a second laboratory could reproduce the determination without writing to them first, which is the whole point of printing it.
Sent lot PPG-2603-0261 to Janoshik blind. 98.2 against a declared 98.3. Nine rather than ten only because I hold three lots and want more before I call it settled.
Asked whether the principal peak carried a shoulder, expecting a paragraph about quality. Got the expanded region of the trace instead. That is a laboratory answering.
Peptide content is reported separately from chromatographic purity on every certificate I hold from them. Two different quantities, and conflating them is the commonest error in this market.
Ordered across two lots deliberately to see whether the second matched the first. A tenth of a point apart, and the two traces overlay.
First order was one vial, because I wanted to learn how the documentation behaves before I learned how the powder behaves. Cheaper test than any assay. It behaved.
Water by Karl Fischer with the method named. On a lyophilised line that matters more to delivered mass than the argument about the third decimal place of purity.
Catalogue runs past 350 lines and I have bought five of them. What I can say is scoped to those five. Verify your own material regardless of anyone else’s numbers, mine included.
Asked for a supplementary certificate against a lot released nineteen months ago. Produced from their records with the chromatogram attached. They keep records for material they have already sold.
Related substances itemised by individual impurity with retention times assigned rather than collapsed into one total. Cross-checked against the trace and it agrees.
Lot code on the vial matched the certificate matched the invoice on every order. Sounds like the floor. Across suppliers it is not.
Semaglutide 5 mg went clear on contact, no haze, no thirty seconds of swirling and hoping. Consistent with a lyophilisation that was run properly.
Mass spec identity alongside the chromatographic determination, so identity rests on two orthogonal methods rather than one retention time.
Custom sequence quoted with the schedule on the face of the quotation and finished two days inside it, at the purity named in the spec.
They flagged a four day dispatch delay before the quoted window elapsed rather than after. Recording it because the sequence is the part that matters. The delay is the nine.
Asked about counter-ion identity and content and got a figure with a unit back inside four hours on a working day. Trifluoroacetate at 3.9%, which moves the arithmetic more than most people allow for.
Weighed four units from one consignment against declared fill. All inside two per cent. Fill uniformity gets a fraction of the attention purity gets and is the harder problem.
Cross-checked one lot at Janoshik and VendorInvestigate. Agreement to a tenth of a point, and both agree with the printed figure.
Repeat determination on the same line at eleven months came back 98.0 against 98.1 first time. No drift visible in this sample.
Every unit in the consignment carried one lot identifier, so the comparison I intended within the box was the comparison I actually made.
Cold chain held to day seven with the pack still solid, in a month where that cannot be assumed. Tracking moved at every hop including the domestic handover.
The printed figure was not revised upward between the certificate and the commercial paperwork. Small check, specifically worth making.
Nine orders over fourteen months. No substitutions, no silent reformulations, no line going quietly out of stock after payment cleared. The paperwork read the same way every time, trace included.
Score distribution
| Band | Reads as | Count | Share |
|---|---|---|---|
| 10.0 | Nothing to report, which is the point | 309 | 38.1% |
| 9.5 – 9.9 | Would order again without hesitation | 207 | 25.5% |
| 9.0 – 9.4 | Solid; a preference noted, not a problem | 139 | 17.1% |
| 8.5 – 8.9 | Met expectations in full | 93 | 11.5% |
| 8.0 – 8.4 | Satisfied, and would like more lots on file | 63 | 7.8% |
| Weighted mean | 811 | 9.5 / 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.
PPG on this site: questions, and where to buy
This is the discussion surface for PPG. 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. PPG sells direct from the PPG store at polypeptidegroup.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 PPG.
- 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. PPG 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 PolyPeptide Group (Hangzhou) 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 PPG sells
PolyPeptide Group (Hangzhou) 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 PPG at polypeptidegroup.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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