A lot of bodybuilders consider Oxymetholone to be the strongest oral that there is for sheer mass gain. It is important to note that some of this mass will be from water bloat caused by the steroid. While Oxymetholone is a DHT derived compound and therefore can’t convert directly to estrogen, it still is known for many estrogenic related side effects. Some have speculated that Oxymetholone somehow triggers the body’s natural estrogen receptors into overdrive. Stronger anti-estrogens such as Letrozole and Exemestane have been shown to greatly suppress the body’s estrogen levels and can both be very effective in keeping these types of side effects to a minimum while using Oxymetholone.