A 10mg CJC/Ipa blend is typically 5mg of each, so your math checks out — 3mL of BAC water gives you 1.67mg/mL per peptide, and 12 units on the syringe lands you right at 200mcg of each. When calculating blends like this, just use the mg amount for one peptide (5mg in this case) since they're equal. Honestly, I'd recommend running the numbers yourself a few times for other doses like 100mcg and 250mcg, then cross-checking against a peptide calculator until your math consistently matches — that way you'll never second-guess your doses.