Accepted answer
Keeping a record turns a vague worry into something a professional can act on.
Keep a written log: date, dose, lot, site, and anything noticed. It converts an anecdote into a record and is what makes any later consultation productive.
Cost per milligram, adjusted honestly
| 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 |
Tell a clinician. The most common reason a problem becomes serious in this space is that the person having it withheld the relevant fact from the person who could have helped.
Withheld information is a recognised barrier to effective clinical assessment, and disclosure changes management in a substantial fraction of cases.
Test your own material. Everything else is downstream of knowing what it is.
edited 21 Mar 2026 by label_claim — removed a claim I could not source