Sustanon 250, being a Testosterone product, suffers from the issue of aromatization which has already been discussed (and will be further expanded upon when Sustanon 250 side effects are covered). Therefore, without the use of an aromatase inhibitor, one can expect a large amount of mass gains accompanied with water retention. This is usually preferable to those who do not mind the additional water gain, and this is usually associated with those who wish to utilize Sustanon 250 in bulking and strength gaining cycles. Sustanon 250 can also be utilized for lean mass and cutting cycles, but only with the use of an aromatase inhibitor in order to control Estrogen production as a result of aromatization. Without the addition of an AI, water retention and possible fat retention/gain will present itself.