Boldenone undecylenate is a very versatile drug, and can be combined with a number of other agents depending on the desired result. For mass, it is commonly stacked with an injectable testosterone such as enanthate or cypionate. This should produce strong gains in muscle size and strength, without the same intensity of side effects of using testosterone (at a higher dose) alone. During a cutting phase, muscle hardness and density can be greatly improved when combining boldenone undecylenate with a non-aromatizable steroid such as trenbolone acetate or methenolone enanthate. Oral c-17 alpha alkylated agents such as fluoxymesterone or stanozolol may also be used, but will present some level of hepatotoxicity. For some, even the low buildup of estrogen associated with this compound is enough to relegate its use to bulking cycles only.
Stephan Bonnar and Josh Barnett , mixed martial arts (MMA) fighters from the UFC and PRIDE Fighting Championships , have also tested positive for the banned substance.  After the World Extreme Cagefighting show on January 20, 2006 Muay Thai turned MMA fighter Kit Cope also tested positive for boldenone.  Following the Strikeforce card on June 22, 2007 former PRIDE and UFC fighter Phil Baroni tested positive for boldenone, as well as stanozolol .  At a K-1 WGP event in Las Vegas on August 17, 2007 two fighters, Rickard Nordstrand and Zabit Samedov , both tested positive for boldenone.  Alexandre Franca Nogueira tested positive for boldenone in July 2008.