Compression fittings don't require teflon tape or pipe compound, but they do require a compression ring (ferrule).

Do you need PTFE tape on compression fittings?

Compression joints on brand new pipe work should be fine without PTFE tape, but older pipework is more likely to weep when things are moved around, i.e. you are changing a radiator over. ... Use of PTFE tape, plus a thin coat of plumber's jointing compound, will ensure a nice tight seal and prevent leaks.

Is a ferrule the same as a compression fitting?

In small sizes, the compression fitting is composed of an outer compression nut and an inner compression ring or ferrule (sometimes referred to as an "olive") that is typically made of brass or copper or steel. Ferrules vary in shape and material but are most commonly in the shape of a ring with beveled edges.