Dostinex (cabergoline)

Cabergoline is a selective dopamine receptor agonist. This agent is highly specific in its actions, with a strong affinity for the dopamine D2 receptor, and a low affinity for dopamine D1, A1-adrenergic, A2-adrenergic, 5-HT1-serotonin, and 5-HT2-serotonin receptors. Its main clinical use is for the treatment of hyperprolactinemia, or the hyper secretion of prolactin from lacto tropes in the anterior pituitary. It is also used in the management of Parkinson’s disease. This drug effectively inhibits prolactin secretion by mimicking the actions of dopamine on the D2 receptor. Cabergoline was developed during the 1980s. The most popular brand name for the drug is Dostinex, which is produced in the United States and many other countries around the world by the large pharmaceutical company Pharmacia. This company did have exclusive rights to the sale of the drug until 2005 when the FDA began approving several generic brands of the drug for use. The Dostinex brand still dominates the global market. Cabergoline is most commonly found in tablets of 500mcg each.

Steroid users should be concerned about excessive prolactin levels because of the side effects associated with them. Prolactin is a naturally occurring hormone primarily produced by the lactotrophs located in the pituitary gland, with a minority amount of the hormone being produced by other tissues/cells of the body. Prolactin plays a major role in lactation in most mammals including humans. It both stimulates milk production as well as inducing lobuloalveolar growth of the mammary gland. Obviously both of these side effects would be of great concern to bodybuilders and strength athletes from both a health and cosmetic standpoint. Decreased sex drive, sperm production and sexual function may also be related to elevated levels of this hormone. In fact even in men with regular healthy levels of prolactin cabergoline can help to temporarily reduce the amount of the hormone that is secreted which leads to such advantages as an increase sex drive, improvement in sexual function (quality of erection) as well as reducing the refractory period for users (the amount of time between erections). Cabergoline works to inhibit secretion of prolactin because it is a dopamine receptor agonist. This means that it acts upon dopamine receptors in the same way as dopamine does in the body. Dopamine acts as a prolactin inhibitor by binding to receptors in the lactotrophs in the pituitary gland and signals for these to cease the synthesis and secretion of prolactin. While dopamine exhibits an ability to inhibit the secretion of prolactin it of course has numerous other functions in the body, with cabergoline being able to mimic the action of dopamine and also performing many of these. These functions include creating a sense of wellbeing or contentment via a chemical reaction in the body, most often released during pleasurable or satisfying physical actions. It has even been shown that dopamine-receptor agonists such as cabergoline can help increase the likelihood that individuals that are quitting smoking be successful. Dopamine can also help improve brain function. For this reason cabergoline is sometimes prescribed to sufferers of Parkinson’s disease. For the average user however it may help in improving memory or even motor functions, although if normal dopamine levels are already being produced by the user this effect will likely be minimal at best. However the primary reason for use of cabergoline by steroid users remains for the treatment of prolactin related side effects.

When used by athletes and bodybuilders to prevent certain side effects from the use of steroids, users  usually start off with a dosage of 250mc twice per week. After 4-5 weeks the user may choose to up the dosage to 1mg per week (2 full tablets usually).