best way to think about EQ is that its just testosterone , minus the androgen and estrogen load. thats why its a great ‘filler’ drug. lets say you wanted to run 1500mg of test, but your both androgen and estrogen sensitive . well you can easily get to that 1500mg range by simply running only 500mg of test and then fill in the rest with 1000mg of Eq. thats gives you a 1500mg of test equivalent but with much less androgen and estrogen load.
Deca on the other hand is an entirely different beast . theres no comparison between deca and eq. deca is a progestin, eq has zero progestin effects.
side note- Eq and Dbol are the exact same drug on paper. Eq is simply the unmethylated injectable version of dbol . of course the way the liver metabolizes them they act very differently in the body,, but on paper they are structurally the same compound