There are possible estrogenic side effects of Nandrolone despite it not being a very estrogenic hormone, at least not directly. Nandrolone does aromatize slightly. Aromatization refers to the conversion of testosterone to estrogen . This takes place when the testosterone hormone interacts with the aromatase enzyme. When the conversion takes place this can cause estrogen levels to go up, which can promote gynecomastia and water retention. High blood pressure can also become an issue if water retention becomes severe. Along with the low level of aromatase activity Nandrolone is also a progestin and has a strong binding affinity for the progesterone receptor. This may stimulate the mammary tissue and enhance the risk of gynecomastia in sensitive individuals.
Combating the estrogenic side effects of Nandrolone can be achieved by the use of anti-estrogen medications, specifically Aromatase Inhibitors (AI’s) such as Anastrozole ( Arimidex ). Selective Estrogen Receptor Modulators (SERM’s) are also sometimes used, such as Tamoxifen ( Nolvadex ). However, AI’s are the proper choice as they will directly reduce serum estrogen levels and SERM’s will not. An AI should be enough to reduce and avoid gynecomastia unless the individual already has existing gynecomastia that could potentially be exasperated.
Important Note: It’s often been said that Nandrolone based gynecomastia is based on increases in prolactin. It is true that 19-nor steroids can increase prolactin, which can also negatively affect libido and erection function. Some men may need to use a dopamine agonist to combat this. However, it is not prolactin that causes 19-nor based gynecomastia but rather the imbalance between estrogen and progesterone. If you merely combat prolactin you may find yourself with the very gynecomastia you tried to avoid.
Non-medical users of anabolic steroids often “stack” different anabolic steroids over the course of a “cycle” of use. They also administer various ancillary drugs and substances to enhance the desired effects of anabolic steroids or to minimize adverse side effects. The most common liquid (injectable) anabolic steroids encountered in these cases are (oil-based) esters of testosterone (., testosterone cypionate, testosterone enanthate, and testosterone propionate, and a blend of testosterone esters called Sustanon 250) or nandrolone (., nandrolone decanoate). Also popular are Equipoise (boldenone undecylenate) and trenbolone acetate and trenbolone enanthate, as well as the water-based injectable Winstrol (stanozolol). Popular oral anabolic steroids include methandrostenolone (Dianbol), oxandrolone (Anavar) and oxymetholone (Anadrol 50).
Sustanon 250 is a potent combination of four esters; testosterone propionate, testosterone phenylpropionate, testosterone decanoate and testosterone isocaproate. All four esters have different half lives; propionate has a half life of one day, phenyl propionate has a half life of 1 to 2 days, the half life of isocaproate is 4 to 5 days and that of decanoate is 7 to 8 days. The esters having short half life release quickly in the body but wear off quickly too thereby needing frequent doses. The esters with a long half cycle stay in the body for long but take time to become active. The different half cycles make Sustanon 250 quite useful and the users require just one dose per week. This is one of the reasons users buy Sustanon 250.