Quantum Peptides vs Growth Guys: COA Transparency Compared

Honest comparison · verified October 2026

Quantum Peptides vs Growth Guys: COA Transparency Compared

How Quantum Peptides and Growth Guys really compare — both verify at an independent lab, so the honest difference is Canadian testing and whether the vial in your hand carries a lot number that ties back to a certificate.

Browse the catalogue See our COAs Per-batch lab results

Full disclosure: this comparison is published by Quantum Peptides, so we’re not a neutral party — we have an interest in you choosing us. To keep it fair, every Growth Guys detail below reflects only what Growth Guys states on its own website (checked 19 October 2026) and on a retail vial we purchased in August 2026, and where something isn’t stated we say ‘not publicly disclosed’ rather than assume the worst. Verify both of us before you buy.

The seven questions, side by side

These are the questions we publish on our own COA page and invite every buyer to ask any supplier. (We recently split the old vial question in two — a lot number and printed dates are separate promises, and suppliers deserve separate credit for each.)

The seven questions	Quantum Peptides	Growth Guys
Do you have a valid Certificate of Analysis?	✓ YesDownloadable per-lot COA before purchase	✓ YesJanoshik lab reports published at /lab-results/
What date was the testing done?	✓ YesTest date on every certificate — current-lot COAs	PartialReports are dated, but freshness varies widely by product — from October 2026 back to January 2026 at review
Does the COA match the lot that you received?	✓ YesLot-matched — the lot number on your vial appears on its certificate	✗ NoCOAs carry Janoshik batch codes (e.g. RET23) — nothing printed on the vial matches them (vial purchased Aug 2026)
Is there a lot number on the vial that ties back to that COA?	✓ YesLot number printed on every vial	✗ NoNo lot number on the vial — the printed CAS number and molecular formula identify the compound, not your batch
Are the manufacturing and expiry dates printed on the vial?	✓ YesManufacturing & expiry dates printed on every vial	✗ NoNo manufacturing or expiry date on the vial we purchased
Where was the test done — in Canada or otherwise?	✓ YesIndependent lab testing in Canada (British Columbia & Alberta)	— Janoshik (Czech Republic) — Canadian testing not stated
Can I view the test results for my specific product on the testing facility’s own website?	✓ YesPublic COA lookup on the lab’s own site — no login needed	✓ YesReports link to verify.janoshik.com

✓ Yes = stated on the vendor’s own site (or confirmed on a vial we purchased) · Partial = some of it · ✗ No = checked and absent · — = not stated at review (19 Oct 2026; vial Aug 2026).

Vial → Certificate → Lab. We are not aware of another Canadian supplier that does all three: prints the lot number, manufacturing date and expiry on the vial, runs testing in Canada, and lets you verify that result on the testing lab’s own website. Break any link in that chain and “third-party tested” stops meaning anything.

TRACEABLE lot # on the vialCANADIAN tested in CanadaVERIFIABLE check it at the lab

Lot-Matched COA — Each vial’s Certificate of Analysis traces directly to its production batch. The lot number matches — traceable, verifiable, yours to confirm. That is the standard every row above is really testing: not “is there a lab report somewhere,” but “does the report belong to the vial in your hand.”

Beyond the seven questions. We also randomly select samples from each supplier order for independent endotoxin testing and heavy-metal screening. Our latest sampled lots — Retatrutide 10mg, CJC-1295/Ipamorelin 10mg and HCG 10,000 IU — reported both as not detected within the tests’ detection limits, with the reports published in our COA library. It’s a sampling program, not per-vial testing — and we say so, because that’s the standard this page holds everyone to.

A fair read on Growth Guys

Growth Guys is one of the most-searched peptide and HGH suppliers in Canada, and to their credit they run a real verification trail. Their lab-results page publishes Janoshik Analytical reports, each tied to a batch or product code, and the reports link straight to verify.janoshik.com so you can confirm them on the lab’s own system. When we re-checked in October 2026 the program was active, with tests as recent as that month. That’s a legitimate setup — far better than a vendor that shows you nothing, and we’d rather you buy from Growth Guys than from one of those.

But in August 2026 we did what any buyer can do: we ordered a Growth Guys vial and looked at the label. Three things stood out.

1 · The numbers on the vial aren’t lot numbers. The label carries a CAS registry number and a molecular formula — identifiers of the compound itself, shared by every vial of that compound ever made anywhere. Their Janoshik COAs are batch-coded (e.g. RET23), but nothing on the vial repeats any of those codes, so you cannot tie the vial in your hand to any specific report.

2 · No dates on the vial. We found no manufacturing or expiry date printed on the vial we purchased, and no way to judge whether the certificate that exists is still the certificate that applies.

3 · Where the testing happens. Janoshik is an independent lab, but it tests in the Czech Republic. Our HPLC and mass-spec testing is done in Canada, by an independent Canadian lab with a public COA lookup. For a Canadian buyer who wants domestic testing and a short chain of custody, that’s a real distinction; if an independent EU lab is fine by you, Janoshik is a credible one.

Every Quantum vial carries its lot number, manufacturing date and expiry (for example, lot 260604, mfg 2026-06-04, exp 2028-06-04), and that lot number appears on its certificate. Both of us let you verify a result on the testing lab’s own website — that part is genuinely comparable. The difference is whether the paper trail starts at your vial.

Those numbers on a vial aren’t lot numbers

Some vials carry scientific-looking identifiers — for example a CAS registry number like 9002-61-3 or a molecular formula like C₁₀₅H₁₆₉N₂₇O₃₂. Those identify what the compound is. Every vial of that compound ever made, from any factory, in any year, shares the same CAS number and formula. They say nothing about which production lot your vial came from, and they cannot connect your vial to any lab report. Try entering one at a testing lab’s verification portal — it returns nothing, because it isn’t a lot number.

A real lot number is assigned per production run, printed on the vial, and repeated on that lot’s Certificate of Analysis. If a vial shows only a CAS number or a formula, the traceability chain is broken at the first link.

Frequently asked questions

Is Growth Guys legit?

Growth Guys publishes third-party Janoshik lab reports on its lab-results page, each tied to a batch or product code and linked to Janoshik’s own verification portal (verify.janoshik.com). That’s a legitimate, checkable setup, and it was active when we re-checked in October 2026. Two caveats from a vial we purchased in August 2026: the vial itself carries no lot number (only a CAS number and molecular formula, which identify the compound, not the batch), and no manufacturing or expiry date. Janoshik tests in the Czech Republic rather than in Canada.

What do the CAS number and formula on a Growth Guys vial mean?

A CAS registry number (such as 9002-61-3) and a molecular formula identify the substance itself — every vial of that compound ever produced shares them. They are not lot numbers and cannot connect your vial to a specific lab report. Entering them at verify.janoshik.com returns nothing, because the portal verifies report codes, not compound identifiers.

What’s the main difference between Quantum Peptides and Growth Guys?

Both publish verifiable third-party COAs. The differences: Quantum’s testing is done by an independent lab in Canada with a public COA lookup, and every Quantum vial carries a lot number, manufacturing date and expiry, with the same lot number on its certificate. On the Growth Guys vial we purchased, there was no lot number and no dates, so the vial can’t be tied to a specific report.

Want the whole market in one table? See our full ranking: Best Canadian peptide suppliers, ranked by COA verification.

Research use only. Quantum Peptides products are supplied as laboratory reference materials for in-vitro research and are not for human or veterinary use. This page compares supplier documentation and testing transparency only; it makes no health, therapeutic, or performance claims. Competitor details reflect what was publicly stated on the vendor’s own website on 19 October 2026, plus a retail vial we purchased in August 2026, and may change — verify before purchase.