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Tirzepatide testing in Canada

Identity confirmed by mass spectrometry, purity measured, and the milligrams of peptide actually in your vial reported as a separate figure. Analyzed in Ontario — your sample never crosses a border.

$249CAD

Results in about five business days from arrival

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  • Identity by LC–MS/MS
  • Purity, with the method stated
  • Net peptide content in mg
  • Chromatographic peak data
  • Certificate anyone can verify

A 39-residue chain with a fatty acid bolted on

A 39-residue synthetic peptide carrying a C20 fatty diacid attached through a PEG spacer at Lys20. That acylation is the most demanding part of the synthesis, and it is where a sample most often diverges from its label.

Residues
39
Formula
C225H348N48O68
Mol. weight
4813.5 Da
Also called
Mounjaro, Zepbound

Where a tirzepatide vial goes wrong

The substitution

Tirzepatide is expensive to synthesise. Semaglutide is cheaper and serves the same market, which makes it the obvious thing to put in a vial labelled tirzepatide.

The two differ by roughly 700 daltons. That is a large gap by the standards of this work, and mass spectrometry separates them without difficulty — but only if the laboratory is weighing the molecule rather than timing how long it takes to travel through a column.

The harder one

Retatrutide sits much closer.

4813.5  vs  4731.3

Tirzepatide against retatrutide — 82 daltons apart, about 1.7%

That is the difference between a 5 kg bag of flour and one with an extra 85 grams in it. Distinguishing them takes genuine mass accuracy, not a nominal figure. How mass spectrometry tells them apart.

What the largest dataset found

13.8%

of tirzepatide samples met both criteria under the stricter manufactured-drug standard. 58.8% had acceptable purity but the wrong amount in the vial — consistent purity paired with frequent dosing inaccuracy. Tirzepatide also showed one of the three widest spreads in measured amount across vendors.

Mendias C, Awan T, 2026 — 6,441 grey-market samples across 14 compounds and 203 synthesis companies. Posted as a preprint; not peer reviewed. The dataset is self-selected third-party testing, so buyers who already suspected a problem are over-represented. Full findings and caveats.

What your certificate reports

  1. Identity — confirmed from precursor-to-product-ion transitions on a triple quadrupole instrument, not inferred from retention time.
  2. Purity — measured at the quantifying transition, with the method named on the report.
  3. Net peptide content — quantified against an external calibration curve and reported as its own figure, in milligrams. Why this is a different number from purity.
  4. Peak data — the chromatographic results behind each figure, printed on the certificate rather than held back.

Common questions

How much sample do you need?

One unopened vial. Detailed posting instructions arrive with your order confirmation, immediately after you pay.

Does it need to be shipped cold?

No. Lyophilised peptides travel safely at room temperature, which is how nearly all samples reach us.

Who actually performs the analysis?

An independent Ontario laboratory. Every certificate we issue names the facility that ran it — we are a testing service, not a laboratory, and we would rather say so than let you find out from the report.

What if the result comes back bad?

You get the result. We do not soften findings, and we do not charge differently depending on what the analysis shows.

Can I verify the certificate is genuine?

Yes. Every certificate carries an identifier that anyone can check against our records, including the vendor you bought from.

Related reading

ExplainedPurity is not contentA vial can be 99% pure and hold a quarter less peptide than the label says.ExplainedHow labs know what is in a vialMass spectrometry without the jargon, and why weighing beats timing.Related testRetatrutide testingThe compound most often confused with this one.

Test your tirzepatide

$249 CAD · about five business days from arrival · never leaves Canada

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