Q&A about peptides and testing

Peptides are short chains of amino acids — the same building blocks that make up proteins — typically between two and about fifty links long. Each peptide has a defined sequence, and that sequence determines its exact molecular mass, which is what our mass spectrometry testing measures. Our article on how peptides get made explains the chemistry and the manufacturing process in plain language.

Research peptides are compounds sold online and labelled for laboratory research rather than human use. They are manufactured and sold outside pharmaceutical regulation, so no authority checks that a vial contains what its label claims. That gap between label and contents is the reason independent testing exists.

Peptide testing is laboratory analysis that establishes what a sample actually is (identity), how clean it is (purity), and how much peptide the vial really holds (net content). Contamination screening — bacterial endotoxin and heavy metals — can be added. The results are reported on a verifiable certificate of analysis.

That depends on the method. The laboratory we work with uses mass spectrometry (LC–MS/MS): the sample is dissolved, separated by liquid chromatography, and the instrument weighs the molecule and its fragments against the expected values for the stated compound, quantifying the amount against a reference standard. Many other peptide testing services rely on HPLC alone, which times a molecule rather than weighing it. Our article on HPLC vs. mass spectrometry explains the difference.

A certificate of analysis is the document a laboratory issues to report what it measured in a specific sample: identity, purity, quantity, and the methods used. A meaningful COA names the laboratory that ran the analysis and states the method behind every figure. Every Veriphase certificate does both, and carries a code anyone can check against our records.

A COA supplied by the seller is a claim made by the party with the strongest interest in a good result. When researchers tested 6,441 grey-market peptide samples against the compounded-medication standard, 41.6% failed on purity, identity or quantity — label claims notwithstanding. An independent certificate is one produced for the buyer, by a laboratory with no stake in the outcome.

Purity is the share of the peptide-related material in a vial that is the intended molecule, rather than fragments, truncated sequences or synthesis by-products. It is expressed as a percentage and measured chromatographically. Purity says nothing about how much peptide is in the vial — that is a separate measurement.

Net peptide content is the actual amount of peptide in the vial, in milligrams, measured against a reference standard — the figure to compare with the label claim. A vial labelled 10 mg can be 99% pure and still contain 6 mg. Purity and content answer different questions, and a complete certificate reports both.

Because purity describes quality, not quantity. The powder in a vial is typically part peptide and part salt and water left over from manufacturing, and the peptide portion can be smaller than the label claims while still being immaculately pure. In published testing, 32.8% of samples were pure but held the wrong amount. Purity is not content covers this in depth.

Mass spectrometry weighs molecules. Every peptide sequence has an exact, known mass — ipamorelin, for example, shows its singly-charged peak at m/z 712.4 — and the instrument also breaks the molecule apart and weighs the fragments, which confirms the sequence itself. A matching mass and fragment pattern is strong, direct evidence of identity.

HPLC times a molecule — how long it takes to travel through a column — and infers identity from that travel time. Mass spectrometry weighs the molecule and its fragments. Two different molecules can share a travel time; they very rarely share an exact mass and fragment pattern. The full comparison is here.

In the largest published dataset — 6,441 grey-market samples across 14 compounds and 203 synthesis companies — 41.6% failed the compounded-medication standard on purity, identity or quantity. Results varied sharply by compound: retatrutide samples passed 68% of the time, TB-500 just 23%. See the full findings.

Endotoxins are fragments of bacterial cell walls that can enter a product through water or equipment during manufacturing. In published testing, roughly 15% of samples showed elevated endotoxin — and endotoxin levels were statistically unrelated to purity, so a high purity figure does not rule them out. The standard test is kinetic chromogenic LAL, USP <85>.

Yes. In May 2026, ECRI and ISMP warned that wellness peptides they examined ranged from 5% to 75% purity and that some contained arsenic and lead above injectable-medication thresholds. Standard purity testing does not detect metals; that requires elemental analysis by ICP–MS, available as an add-on to any Veriphase test.

Not by looking — every peptide is a white powder, and a label is a claim, not a measurement. The only direct evidence is analysis: LC–MS/MS compares the measured mass against the known target (4,813.5 Da for tirzepatide) and quantifies how much the vial holds. Veriphase tests semaglutide, tirzepatide and retatrutide individually.

Veriphase tests run from $149 to $299 CAD depending on the compound, with most single-compound tests at $249 CAD. Every test includes identity, purity, net peptide content, chromatographic peak data and a verifiable certificate — contamination screening can be added. Current pricing for every compound is on Tests & prices.

About five business days from the day your sample arrives at the laboratory, with the certificate delivered electronically. Because testing happens inside Canada, there is no cross-border shipping, no customs broker and no import delay on the sample getting there.

Veriphase receives samples from across Canada — Toronto, Vancouver, Montreal, Calgary, Edmonton, Ottawa and everywhere in between — by regular domestic post. Analysis is performed at an independent laboratory in Ontario, and results are delivered electronically, so distance makes no difference to turnaround.

Most lyophilized (freeze-dried) peptides are stable at room temperature for far longer than a domestic shipment takes, so no cold packs or special handling are needed for most compounds. The certificate reflects the sample as received, and the laboratory flags any sample that arrives damaged before analysis begins.

Every certificate carries a QR code and an ID. Scanning the code — or entering the ID at veriphase.ca/verify — checks the document against our records and confirms the certificate and its figures are genuine. Anyone can run the check: the researcher who ordered the test, or a vendor shown the certificate.