The relevant framing is that risk here comes from three separate places: what the material is, how it is handled, and what it does. They need three different mitigations.
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.
Do not combine unknowns. Adding a second unverified compound while assessing the first makes any observation uninterpretable and doubles the exposure.
Withheld information is a recognised barrier to effective clinical assessment, and disclosure changes management in a substantial fraction of cases.
The safest option in every case is not to use unapproved material at all, and that should be said rather than implied.
Tell a clinician. It is the decision that makes every other problem solvable.
edited 7 Apr 2025 by fiadh_cronin — expanded the table to cover the lower concentration