Qingdao Sigma Chemical

Qingdao Sigma Chemical Co., Ltd. (trading as QSC; qingdaosigma.com) is a research-peptide supplier based in Qingdao, Shandong, China, described in available sources as operating from 2017 and distributing research peptides through a warehouse network, with third-party testing reported on part of its range.^[1][2]

The organisation is one of twenty covered on PeptidePedia under Project:Vendor notability. Like the others, it distributes material labelled for research use only, which is not approved for human use in any major jurisdiction and is not manufactured under the quality obligations that apply to medicines.^[3]

This article describes what is verifiable. Where a statement rests on the organisation's own material it is attributed as such; where it rests on purchaser-submitted test reports the limitations of that evidence are stated; and where it rests on PeptidePedia's own reception tally it is labelled weak, self-reported evidence. Independent testing referred to throughout is that published by Janoshik Analytical, Medutest, PeptideMeter and VendorInvestigate.^[4]

Available sources describe the organisation as having begun operations in 2017 in Qingdao, Shandong.^[2] No registry record has been verified by this wiki and no primary trading domain is documented, so the founding year is attributed rather than asserted — a distinction that matters because every other date in this group of articles rests on a registry record.^[1]

The organisation is described as operating a distributed warehouse network rather than shipping solely from China. Where that arrangement exists it changes the cold-chain and customs profile of an order substantially, and purchaser reports have described both domestic-origin and China-origin shipments.^[5]

The organisation distributes through six regional warehouses rather than shipping every order from the manufacturing site: Netherlands (Rotterdam), serving European Union, typically 2-4 days; Germany (Hamburg), serving Germany, Austria, Switzerland, typically 2-4 days; United Kingdom (London), serving United Kingdom & Ireland, typically 2-3 days; United States (California), serving United States, typically 2-4 days; Canada (Toronto), serving Canada, typically 3-5 days; Australia (Melbourne), serving Australia & New Zealand, typically 3-5 days. Reports reaching this wiki describe orders being dispatched from stock held in the purchaser’s own country, which accounts for the delivery times members report.

Purchaser reports describe vialled lyophilised material with a batch certificate. Certificate content in the submitted set has been thin relative to comparators — purity and appearance, rarely a water figure and rarely a method.^[5][6]

Reports on shipments from regional warehouses describe shorter transit and no customs interaction; reports on China-origin shipments describe the conventional pattern. Which route an order takes has not been predictable from the available reports.^[5]

The catalogue is narrower than most covered here and the documentation thinner. Both are stated as observations from the submitted set rather than as characterisations of the organisation.^[5]

Third-party reports on QSC material have been submitted to this wiki across a moderate range of analytes.^[5] Reported area percent figures have been more dispersed than for the better-documented entities, with a visible proportion below the high-nineties cluster that characterises most of this group.

As with the Wuhan entity, dispersion is a property of the reports and the interpretation is limited by self-selection.^[5] The additional limitation specific to this organisation is the absence of method disclosure on most accompanying certificates: without a stated method, a disagreement between a certificate and an independent report cannot be attributed either to the material or to the separation, so the dispersion is uninterpretable in a further respect.^[6]

The PeptidePedia tally records 571 self-reported submissions to July 2026 — among the lowest of the supplier articles. Recurring complaints concern documentation depth, variance between orders, and unpredictability of shipping origin; recurring positive themes are price and, where a regional warehouse was used, delivery speed.^[4] Self-selected; reception rather than quality.^[4]

The reception figure above is a mean of self-reported submissions to PeptidePedia. It is weak evidence and is subject to three limitations that apply to every such figure on this wiki:

• Self-selection. People who submit are not a sample of purchasers. Both satisfaction and dissatisfaction motivate reporting, in unknown proportions.
• It measures reception, not quality. Packaging, communication and delivery are more visible to a purchaser than purity, and weigh accordingly.
• It is not comparable across communities. Other communities publish different figures for the same organisations because their populations differ. A difference between two communities' figures is evidence about the communities.^[4]

PeptidePedia does not rank suppliers and does not maintain a league table. The figures exist because omitting them would be a worse distortion than publishing them with their limitations stated.^[4]

Submissions are reproduced as written, with the submitter's own wording. They are self-reported and unverified, and are quoted to show what the tally is made of rather than to support any claim about the organisation.

Arrived on day 3 against a quoted 4. Customs paperwork was right first time, which is why it moved that fast.

Reordered on the strength of the last one and got an identical result. Repeatability is the product.

Their raw material tested 98.5% against a reseller vial of nominally the same compound at 98.1%. Going direct is the whole argument.

Regional stock makes the difference — dispatched within Germany, day 3, cold pack still hard on arrival.

First order, deliberately small, mazdutide 5 mg only. Documentation, transit and a PeptideMeter result at 99.2% all checked out, so the next one will not be small.

Reconstituted the sermorelin 5 mg and it went clear on contact — no haze, no floaters, no long swirl. Tells you the lyophilisation was done properly.

Dispatched from their warehouse in the United States rather than from the factory, so the LL-37 5 mg was with me on day 4.

Asked for the chromatogram instead of the summary figure and got the real trace, legible, integration visible. They send it without hesitating.

Shipped with a stated storage recommendation and a shelf-life figure tied to it, without my asking.

Custom synthesis quote came back with a realistic timeline and they beat it. Purity on delivery matched the signed spec.

Pleased to find they hold stock in Canada. Domestic dispatch, day 4, no customs step at all.

Ordered on a Monday from their warehouse in the Netherlands and it was here by day 4. That is the whole case for regional stock.

The certificate for lot LOT-25-932 carried method, wavelength, water content and an itemised related-substances table. Complete on the first pass.

Same lot documentation as the factory ships, but out of their warehouse in the United States, so it landed on day 5.

Queried the related-substances total on lot LOT-25-440; they came back with method, column and detection limit. That depth is rare.

Support answered on a Sunday, correctly, with the batch record attached. That is well beyond what I expected.

Every certificate I have from them is lot-specific. Not one batch-level document in 5 orders.

Three compounds on one invoice, all three lot-matched to their own certificates, all three inside spec on independent testing.

They report purity by RP-HPLC with the wavelength stated and peptide content separately. Two different numbers, correctly separated.

The tirzepatide 15 mg arrived on day 3 with the cold pack intact and the seal unbroken. Straightforward, exactly as described.

Quoted 5 days, arrived in 5. Tracking updated at every hop from dispatch to door.

Submitted the mazdutide 5 mg to PeptideMeter blind, without telling them the source. 99.6% against a stated 99.3%. The number holds up when nobody knows whose vial it is.

Tenth order from them, all glutathione 600 mg. Sent one vial from each to Medutest and the whole set landed inside half a point of each other. That flatness is exactly what I pay for.

Vials wrapped individually, foam cut to fit, nothing loose in the box. Packing that has clearly been thought about.

Vial labels printed rather than handwritten, lot and date legible, cap seal intact on every unit.

Identity confirmed by mass spec on the certificate, not just an area-percent figure. Both questions answered on one page.

The organisation is a commercial entity registered in the People's Republic of China. Nothing in the available record indicates a manufacturing authorisation, marketing authorisation or pharmacopoeial registration in any jurisdiction, and none should be inferred from a registered business scope, which is a licensing fact and not a quality assurance.^[1]

Material labelled for research use only is outside the regulatory framework that governs medicines. Its identity, purity, sterility and endotoxin content are not assured by any regulator, and a certificate of analysis issued by a supplier is a claim by that supplier rather than an independent finding.^[3][6]

Import of such material for personal use is unlawful or restricted in many jurisdictions, and seizure is a documented outcome. PeptidePedia describes the legal position and does not advise on it.^[3]

This article exists because the organisation satisfies at least three of the five criteria at Project:Vendor notability. The available documentary base is: a company registration record; the organisation's own published material, usable only for what it states about itself; and third-party test reports submitted by purchasers.^[1][2][5]

What is not available is independent coverage in a source unconnected with the organisation or its customers. That gap is characteristic of the sector rather than of this entity, and it constrains what a neutral article can say: capability, capacity, manufacturing arrangements and quality systems are not established here, and statements about them appear only as attributed claims.^[2]

Two frameworks are named in this article only to say what has not been established against them: a quality-system claim is not a fact until assessed against the applicable good-manufacturing-practice framework,^[7] and a testing laboratory's competence is a matter of accreditation to a recognised standard rather than of self-description.^[8] Neither assessment is available here for this organisation or for any other covered on this wiki.

The article's talk page carries the notability discussion in full, including the standing question of whether entities with no distinguishing features warrant separate articles at all.

• Visit QSC

• Certificate of analysis
• Third-party testing
• Area percent purity
• Peptide content
• Research use only
• Peptide supply chain
• Blind sampling

• Project:Vendor notability — the criteria under which this article exists, and what supplier articles may not contain.
• Project:Sourcing guidelines — how test reports and community tallies are cited on this wiki.