Nandrolone decanoate, sold under the brand name Decalon or Deca-Durabolin among others, is an androgen and anabolic steroid (AAS) medication which is used primarily in the treatment of anemias and wasting syndromes, as well as osteoporosis in menopausal women. It is given by injection into muscle or fat once every one to four weeks.
Side effects of nandrolone decanoate may include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. The medication is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). It has strong anabolic effects and weak androgenic effects, which give it a mild side effect profile and make it especially suitable for use in women and children. Nandrolone decanoate is a nandrolone ester and a long-lasting prodrug of nandrolone in the body.
Nandrolone decanoate was first described in 1960 and was introduced for medical use in 1962. It was the second nandrolone ester to be introduced, following nandrolone phenylpropionate (NPP) in 1959, and is one of the most widely used nandrolone esters. It is also one of the most widely used AAS worldwide. In addition to its medical use, nandrolone decanoate is used to improve physique and performance, and is said to be the most widely used AAS for such purposes. The drug is a controlled substance in many countries and so non-medical use is generally illicit.
Nandrolone decanoate is approved in the United States specifically for the treatment of anemia of chronic kidney disease and in the United Kingdom specifically for the treatment of osteoporosis in postmenopausal women. In Australia, it is approved specifically for the treatment of kidney failure, chronic kidney disease, anemia of kidney failure, aplastic anemia, osteoporosis (in women in whom estrogens are contraindicated), inoperable breast cancer, and for patients on long-term corticosteroid therapy. In New Zealand, it is approved for osteoporosis, inoperable breast cancer, and as an adjunct to therapy for conditions characterized by a negative nitrogen balance. The drug is often used off-label to preserve lean mass in HIV/AIDS patients and in other wasting syndromes.
In the past, nandrolone decanoate has also been indicated and used for a variety of other conditions and situations including pre- and postoperative use for increasing lean mass, treating weight loss due to convalescence or disease, geriatric states (e.g., general weakness, fatigue), burns, severe trauma, ulcers, and selected cases of growth failure in children. Starting in the 1970s, the indications of nandrolone decanoate were refined and use of the drug became more selective and restricted. Its use in medicine continues to decline and has become limited, with its sale having been discontinued in many countries.
Because of their reduced androgenic effects, nandrolone esters have not generally been used as a form of androgen replacement therapy for treatment of androgen deficiency in men, and have instead been used solely as anabolic agents. However, nandrolone decanoate has been and can be used at low doses as a means of androgen replacement in postmenopausal women, for instance to maintain or increase bone mineral density and decrease the risk of osteoporosis. It is one of only three androgens approved for androgen replacement in postmenopausal women, the others being testosterone (and esters) and methyltestosterone. Nandrolone esters have also more recently been proposed for the treatment of androgen deficiency in men due to favorable properties including their high ratio of anabolic to androgenic effect and consequent much lower risk of scalp hair loss, prostate enlargement, and prostate cancer relative to testosterone.