How many ml are in a line of codeine?

The amount of milliliters (ml) in a line of codeine can vary based on the concentration of the codeine solution being used. Typically, a "line" refers to a small amount of powdered substance, and the measurement in ml would depend on the density and form of the codeine. For example, if codeine is in liquid form, a line might correspond to a fraction of a milliliter, while in powdered form, it would not directly translate to ml. Always consult a healthcare professional for accurate dosing.