Caberos (active agent - cabergoline) an ergot derivative, is a potent dopamine receptor agonist on D₂ receptors. In bodybuilding it is used by males to prevent side-effects (gynecomastia and sexual dysfunction in particular) caused by elevated prolactin levels through the use of 19-nor anabolic steroids (such as nandrolone or trenbolone).

The secretion of prolactin by the anterior pituitary is mainly under hypothalamic inhibitory control, likely exerted through release of dopamine. Cabergoline is a long-acting dopamine receptor agonist with a high affinity for D2 receptors. Cabergoline exerts a direct inhibitory effect on the secretion of prolactin by pituitary lactotrophs.

Besides this main effect, cabergoline also helps to combat other dopamine related conditions like difficulties with concentrating, attention deficit disorder, and depression. Caber has a long active life in the body, so only about 0.25 mg/week are sufficient to experience all of the anti-prolactin, pro-sexual, antidepressant, and cognitive effects of Caberos.

Post-cycle therapy (PCT)