TrialTracker_MD said:

Concentration choice is a precision decision, not a preference.

I am going to disagree with reconstituting low as a general rule. More diluent, more punctures, more in-use days at room temperature, and the stability trade-off is real. Precision is not the only variable being optimised.

I would rather be corrected than agreed with, if it comes to it.

WendyG_ATL said:

Two of us with identical vials and identical diluent arrived at different unit counts, which means one of us has a conceptual error rather than a…

Reconstitution tip for anyone mixing dosing arithmetic from lyophilized powder: use bacteriostatic water, NOT sterile water. The benzyl alcohol in BAC water preserves multi-dose vials for up to 28 days.

Inject the water slowly down the side of the vial. NEVER shake — gentle swirling only until fully dissolved. Should be crystal clear with no particles.

RetaRick_CA said:

I am going to disagree with reconstituting low as a general rule.

Ongoing cost tracking for dosing arithmetic — transparency for the community:

Monthly medication cost: $112
Supplies (syringes, BAC water, alcohol swabs): ~$10/month
Janoshik testing: ~$12/month (amortized quarterly)
Lab work: ~$42/month (amortized quarterly)
Total: ~$202/month

Compare to brand Wegovy at $1302/month without insurance. Compounded is roughly 88% cheaper for what I have found to be clinically equivalent medication.

One thing that is still open after JennaRN’s answer:

How to check the arithmetic without trusting a website calculator, since three calculators gave me three answers?

Closing the loop on my own question.

My error was treating units as a mass. Once I wrote mg/ml on the vial in marker and worked in millilitres first, the two of us got the same answer.