Third-party analysis
Six samples from our range were sent to an analytical laboratory we do not control. Purity, peptide mass and identity came back measured, not asserted — and the numbers are published as issued, with the method behind each one.
Why
Every supplier issues a COA. The document is only worth something if someone other than the seller produced the number — so we buy vials from our own stock and post them to a laboratory that has no commercial interest in the answer.
Three things are measured, and they answer three different questions. Chromatographic purity is the main peak as a share of everything that absorbs at the detection wavelength — it tells you how much of the UV signal belongs to the target molecule. Total peptide mass is how much peptide is actually in the vial, weighed against a reference standard, which is the number that matters when you calculate an assay. Identity is a mass confirmation: the peak is the molecule it claims to be.
A vial can pass the first and fail the second. Purity of 99 % by area with 84 % peptide content is a normal, honest result — the remainder is counter-ion, water and residual solvent. A supplier who quotes only the first number is telling you half the story.
Results
Results are reproduced as issued, with the method behind each figure.
| Sample | Size | Purity (area) | Peptide mass | % of label | Sampled |
|---|---|---|---|---|---|
| BPC-157 | 10 mg | > 99.95 | 10.5 | 104.8 % | Oct 2025 |
| Tirzepatide | 30 mg | > 99.95 | 30.5 | 101.6 % | Oct 2025 |
| Retatrutide | 10 mg | 99.73 | 9.84 | 98.4 % | Oct 2025 |
| Retatrutide | 15 mg | > 99.95 | 14.3 | 95.4 % | Nov 2025 |
| PT-141 | 10 mg | 99.21 | 10.1 | 100.8 % | Nov 2025 |
| Melanotan II | 10 mg | 98.78 | 10.7 | 106.6 % | Nov 2025 |
Purity is the main peak as a share of total peak area. Peptide mass is weighed against a reference standard, and the percentage is against the label claim.
Reading the results
A purity figure on its own is half a specification. Here is how to read the rest.
A lyophilised peptide carries acetate or TFA, water and residual solvent. At 99 % purity the peptide fraction can sit anywhere from 78 % to 90 % by mass depending on the counter-ion and the drying. Two vials can both read “99 %” and deliver materially different amounts of peptide to an assay.
Column chemistry, gradient, detection wavelength and integration window all move the result. An independent laboratory and a manufacturer's release laboratory will not always agree to the decimal — which is why the method matters as much as the figure.
Ask for the report, not the number. Ask which method produced it. Ask whether the sample came from the lot you are buying. A supplier who can answer all three is worth the premium; one who cannot is quoting a decoration.
Disclosure
The reports were commissioned by a customer, and the laboratory's identity, address and report numbers are withheld at that customer's request. What is published here is the analytical data itself — the part that can be argued with.
The unredacted reports are available under NDA to buyers evaluating a specific order. If a supplier will show you a purity figure but not the report it came from, the figure is decoration.
Sales samples are bought from the same stock that ships to customers.
Any quotation can include the third-party data for the product you are evaluating, alongside the batch certificate.
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