Around fifth part of the injected steroid binds to progestin receptors (due to the absence of a carbon atom in the 19 position), and therefore, such reactions as the suppression of secretion of gonadotropin-releasing hormone, increased production of prolactin, a significant decrease in libido should not be excluded. Weak erection - the most pronounced and severe consequence of abuse of deca nandrolone. Exceeding of the recommended dosage and duration of the course may cause rhinitis, headache, back pain, rash. In general, the side effects of nortestosterone decanoate - rather the exception than the rule.
Through its action on the pituitary, danazol indirectly reduces estrogen production by lowering the output of follicle-stimulating hormone and luteinizing hormone. There is also evidence that danazol binds to sex hormone receptors in target tissues, thereby exibiting anabolic, antiestrognic and weakly androgenic activity. With higher doses, amenorrhea generally occurs after about 6 weeks of therapy; ovulation and cyclic bleeding returns to normal 60—90 days after therapy is discontinued. Danazol is used to treat endometriosis because it causes atrophy of ectopic endometrial tissue, which relieves symptoms completely. It also decreases the growth rate of abnormal breast tissue, making it useful in fibrocystic breast disease. Heriditary angioedema is an inherited disorder characterized by a deficiency in C1 esterase inhibitor (C1 INH), a serum inhibitor of the activated first component of complement. Danazol increases circulating levels of C1 INH and therby increases C4 of the complement system, which also is deficient in hereditary angioedema. Consequently, danazol prevents attacks of hereditary angioedema in both males and females. The exact mechanism by which danazol increases C1 INH is not known. Danazol does not possess any progestogenic activity, and does not suppress normal pituitary release of corticotropin, or release of cortisol by the adrenal glands.
Like other AAS, boldenone is an agonist of the androgen receptor (AR).  The activity of boldenone is mainly anabolic , with a low androgenic potency. Boldenone will increase nitrogen retention, protein synthesis, increases appetite and stimulates the release of erythropoietin in the kidneys.  Boldenone was synthesized in an attempt to create a long-acting injectable metandienone , for androgen deficiency disorders. Boldenone acts similar to metandienone with fewer adverse androgenic effects. [ medical citation needed ] Although commonly compared to nandrolone , boldenone lacks progesterone receptor interaction and associated progestogenic side effects.