Learn as you go

Reference guides

Background reading for the calculators — what the units mean, how syringe types differ, and how reconstituted vials are commonly stored. No dosing recommendations, just the concepts behind the numbers.

mg, mcg, and Units — What They Actually Measure

1 mg equals 1000 mcg — both measure the mass of peptide. Units measure something different: they are marks on an insulin syringe, where 100 units equal 1 mL on a U-100. So a dose in mcg converts to units only once you know the concentration you mixed: at 2.5 mg/mL, 250 mcg is 10 units. Here is how the three connect.

U-100 vs U-40 Syringes: Scale vs Capacity

A U-100 syringe has 100 unit marks per 1 mL; a U-40 syringe has 40 marks per 1 mL. The same 0.1 mL of liquid therefore reads as 10 units on U-100 and 4 units on U-40 — the scale changes the number on the barrel, not the volume drawn. Capacity is a separate specification: a "50-unit syringe" is usually a 0.5 mL U-100, not a "U-50" scale.

Storing Reconstituted Peptides

Once a peptide vial is reconstituted with bacteriostatic water, how it is stored affects how long it stays usable. This is general handling information, not advice on how much to use or when.