Dr.ObesityLA 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.
denise_HTX said:I reconstituted a 10mg vial with 2ml of bacteriostatic water and I want someone to check my unit arithmetic before I draw anything, because I keep…
Quick syringe math for dosing arithmetic dosing: if your vial is reconstituted at 5mg/2mL, that's 2.5mg/mL. For a 0.25mg dose you need 0.1mL = 10 units on an insulin syringe.
I keep a chart on my fridge:
- 0.25mg = 10 units
- 0.5mg = 20 units
- 1.0mg = 40 units
- 1.25mg = 50 units
Always double-check your concentration before drawing up!
PurityPaulOR said:I am going to disagree with reconstituting low as a general rule.
For anyone reconstituting dosing arithmetic peptides: the water-to-powder ratio determines your concentration. Here's my reference:
| Vial Size | BAC Water | Concentration | 0.25mg Dose |
|---|---|---|---|
| 5mg | 2mL | 2.5mg/mL | 10 units |
| 5mg | 2.5mL | 2mg/mL | 12.5 units |
| 10mg | 2mL | 5mg/mL | 5 units |
| 10mg | 3mL | 3.33mg/mL | 7.5 units |
More water = easier to measure small doses but vial runs out faster. Find the balance that works for your dose.
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Shop Reference StandardsA narrower follow-up, since the general answer is now clear:
How to check the arithmetic without trusting a website calculator, since three calculators gave me three answers?
OP back with an update, since a thread like this is useless without one.
Follow-up: it was dead space. Switching to a low-dead-space fixed-needle syringe gave me the tenth dose back.