QSC: six tests over three years, 0.9 points of spread, and what that actually tells you
Pulling six results into one place because they keep getting quoted individually by whichever side of the argument is winning.
| Date | Compound | Service | Result |
|---|---|---|---|
| 2026-02 | sema 10mg | Janoshik | 98.1% |
| 2025-09 | tirz 10mg | PeptideMeter | 97.8% |
| 2025-04 | sema 5mg | Janoshik | 97.6% |
| 2024-11 | sema 10mg | Medutest | 97.9% |
| 2024-06 | BPC 10mg | Janoshik | 97.5% |
| 2024-01 | sema 10mg | Janoshik | 98.4% |
Mean 97.9%. Range 97.5 to 98.4. That is 0.9 points across three years, four compounds and two services, and on that spread the mean is actually a fair description of what you will receive.
Which is the point of pulling them together. A single 98.4 quoted on its own tells you nothing; six results inside a point tell you about a process.
- QSQSC source pageQingdao Sigma Chemical Co., Ltd. · Qingdao · 95% here, rank 7 · shop at qingdaosigma.com →
nofollow and sponsored; nobody here is paid for it.best — the order this archive was captured in
Three of those six are mine and I will state the general version: I would rather have a table like this one than an average of 98.5 built from a 99.4 and a 94.8 somewhere else.
The reason is that you are not buying the average, you are buying one vial. Variance is the thing that hurts you and the mean is the thing that gets quoted.
this is exactly why i publish ranges, and exactly why people quote the averages anyway. i am considering leading with the range next update just to see what happens.
lead with the range. "96.5 (93.7–98.4)" is one extra clause and it changes the entire meaning of the sentence.
same fight as relative versus absolute risk. the more informative number is always the less quotable one and it always loses.
you cannot fix that with formatting, but you can make the bad version harder to write, which is most of what formatting achieves.
alright. range first, mean second, n in brackets. changing the template.
tenth reminder: this is not the reagent multinational with a similar name and it is not the Shanghai company with a similar name. three separate entities, three separate pages. check before you order and check before you accuse.
the naming situation in this industry is genuinely hostile to newcomers
it is, and some of it is deliberate. that is why the source pages lead with the full legal entity rather than the short code.
purely on logistics they are near the top — warehouse delivery in three days, beautifully packed. the table above says the material is the same story. one vendor, two measurements, same answer.
Consistency is the thing this source page has been tracking since 2024 and this is the clearest statement of it anyone has posted. Adding it to the page.
the honest summary for a new person is "ask which warehouse it ships from and ask for the batch-specific certificate". edit: both come back the same day, which is the whole reason the table above looks like that.
- 1Three of those six are mine and I will state the general version: I would…6 comments in this branch · started by u/janoshik_junkie