Setup, so nobody has to ask: SSA · survodutide.
Somebody stated this to me confidently and I would like to check it before repeating it.
I would accept a well-reasoned negative answer over a poorly sourced positive one.
What would count as evidence here, and does it exist?
The short version: ask for the lot-specific certificate, check the method section, check the lot code ties to a vial, then spend a small amount and test it yourself.
The pre-order sequence: request a lot-specific certificate for the exact line, check that it names a lot code rather than a batch family, check that it carries the column, gradient and detection wavelength, and check the analysis date is recent relative to the lot.
| Step | Value | Note |
|---|---|---|
| Vial price, 10 mg nominal | £34.00 | As advertised |
| Nominal cost per mg | £3.40 | 34 ÷ 10 |
| Measured content | 9.2 mg | Independent content assay |
| Cost per actual mg | £3.70 | 34 ÷ 9.2 |
| Dead-space loss, 20 draws | 4 % | 80 µL of a 2 mL fill |
| Cost per delivered mg | £3.85 | 3.70 ÷ 0.96 |
| First vial, with £110 assay | £14.85 | Testing dominates a single vial |
The post-arrival sequence: inspect before reconstitution, photograph anything unexpected, confirm the lot code is physically on the vial, and submit a sample to an independent laboratory before committing to a larger order.
Published inter-laboratory comparisons of peptide purity routinely find spreads of half a per cent to a per cent on identical material, which sets a realistic expectation for agreement.
Write your accept threshold down before the result arrives.
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsAnswering this needs to know whether you have already ordered, because the pre-order checks and the post-arrival checks are different lists.
The single most informative free test is asking for the certificate of the lot they intend to ship and then confirming, on arrival, that the code on the glass matches it. A supplier who can do that has a traceability system; one who cannot does not.
Set your accept threshold before you see the result. Deciding after the number arrives is how thresholds become negotiable, and everybody does it unless they wrote it down first.
Aggregate community ratings, including the one on this site, are opinion averages rather than measurements and should carry less weight than a single result on your own lot.
Match the code on the glass to the code on the certificate. Everything else is secondary.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.