TrialNerd_Beth said:

Dead space is the answer to the missing dose.

Saving this. It is the first explanation that did not require me to already understand it.

From the other side of the consultation, briefly.

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.

Dr.ObesityMed said:

Freezing is the one to avoid, and freeze-thaw more so.

Bacteriostatic water quality matters for dosing arithmetic reconstitution. Not all BAC water is created equal:

• Should contain 0.9% benzyl alcohol as preservative
• Must be sterile and pyrogen-free
• Should come in a sealed, intact vial
• Check expiration date — yes, BAC water expires
• Store at room temperature, protected from light

I buy from a reputable medical supply company, not Amazon marketplace sellers. The $3 savings isn't worth the infection risk from unverified BAC water.

ingrid_STO said:

Do it in two steps and it stops being confusing.

For anyone reconstituting dosing arithmetic peptides: the water-to-powder ratio determines your concentration. Here's my reference:

More water = easier to measure small doses but vial runs out faster. Find the balance that works for your dose.

Moderator note: a couple of off-topic posts removed. Report rather than reply if it drifts again.