Masteron does little to nothing by itself, but when added to test and tren it's just short of magic. Very synergistic, i.e. Makes 500 mg test feel like 750mg. Great libido boost and also raises free test.
Primo is said to mimic tren when run at higher doses but it's pretty pricey and needs > 600 mg to be real effective. One of the more mild aas out there. Side effects are less than most but then again so are the results. Women friendly as well