I have purschaded syringes of THC And CBD in syringes marked 1/2 1 1/2 2 1:2 3 I uderstand it’s in cc I need to express it in mg syringes how do I do this and can I

The abbreviation “cc” stands for cubic centimeter and “mL” stands for milliliter, but they refer to the same amount of a liquid. In other words, 5 cc is exactly the same as 5 mL. The two terms can be used interchangeably. Under no circumstances, however, should milligrams (mg) and milliliters (mL) be confused

My sketchy "knowledge" also says cubic centimeter is measure of volume whereas milligram is measure of weight- maybe that's why guy says you need to know density to compute

Hell if i know ! Good luck !

You need to know the density of the liquid to figure that out.