Side Effects of Nandrolone Decanoate Injection

Updated April 17, 2017

Nandrolone Decanoate is a steroid used to treat a variety of medical conditions. Although it is banned from use in sports, many athletes have used it in training. Nandrolone causes a number of side effects, and those suffering from certain conditions should avoid its use. In some jurisdictions, it is illegal without a prescription.

What Is It?

Nandrolone decanoate, also known as Deca-Durabolin, is a pharmaceutically produced version of the naturally occurring steroid hormone nandrolone (19-nortestosterone), and is manufactured by a number of drug companies. Nandrolone strongly resembles the molecular structure of the hormone testosterone, and produces a number of similar anabolic effects. Nandrolone increases muscle mass, promotes bone density and stimulates appetite. It differs from testosterone by having weak androgenic properties (ability to cause masculine characteristics).

Medical Uses

Nandrolone decanoate received FDA approval in 1983 to treat a number of medical conditions. Doctors have used nandrolone's ability to increase red blood cell counts to treat anaemia of the kidneys. It has also been used to treat post-menopausal osteoporosis and in the past, it has been prescribed as a contraceptive for women.

As an oil-based steroid, patients must inject nandrolone into intramuscular tissue. Typical dosages range from 50 to 100 mg peer week for women and 100 to 200 mg per week for men.

Athletic Uses

Nandrolone increases muscle mass by facilitating nitrogen retention in muscle tissues, and consequently, many athletes have taken it to build muscle, increase strength or aid recovery after muscle injury. Nandrolone also helps recovery from and prevents joint injuries by storing excess water (as synovial fluid) in the joints, and this additional joint lubrication has encouraged nandrolone use among strength athletes.

The decanoate ester attached to nandrolone prevents it from being rapidly broken down by the liver, and nandrolone's long half-life (the amount of time it takes the liver to break down half of it) has resulted in many athletes testing positive in competition long after use of the drug.


Men with pre-existing prostate carcinoma (a form of cancer) or members of either sex with breast carcinoma should not take nandrolone. Also, women with hypercalcemia (excess calcium in the bones), or women who could become pregnant during use should not take nandrolone.

Nandrolone is considered a pregnancy Category X drug, which means that it is known to cause birth defects in unborn foetuses.

Also, nandrolone has been known to cause enlarged prostates and prostate cancer in the elderly.

Anyone with pre-existing liver, kidney or heart disease should discuss these conditions with a doctor before taking nandrolone. Additionally, patients should consult a doctor before taking nandrolone if they are taking coagulants or insulin, because nandrolone can affect the action of these medications.

Side Effects

Nandrolone can cause liver cell tumours, and may result in peliosis hepatitis, the formation of blood-filled cysts inside the liver and/or spleen. Both of these conditions can be fatal.

Nandrolone has caused hypercalcemia in women, and also effects blood serum cholesterol, including the lowering of HDL (good cholesterol).

Nandrolone may also result in acne, insomnia, jaundice (yellowing of skin), depression and/or aggression. It may also cause allergic reactions that include diarrhoea, nausea and vomiting.

Sexual Side Effects

While taking nandrolone, patients of both genders may experience change in libido. Men taking nandrolone have developed gynaecomastia (the development of breast tissue), erectile dysfunction (including constant erections), and a change in testicular function and sperm production.

Although nandrolone is a weak androgen, women taking nandrolone might undergo the adoption of male characteristics. These include deepening voice, enlarged clitoris, disruption of menstrual cycle, and increased facial and body hair.


Nandrolone is classified as a Schedule III drug by the U.S. Department of Justice, and under federal law, it is illegal to possess without a prescription. Anyone caught illegally selling, distributing or possessing nandrolone can be convicted of a felony punishable by up to five years imprisonment (state laws vary).

Additionally, the governing bodies of most professional sports, the NCAA, and the International Olympic Committee have all banned their athletes from taking nandrolone. Infractions can result in suspensions, fines or a lifetime ban.

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About the Author

Since 2005, James Rutter has worked as a freelance journalist for print and Internet publications, including the “News of Delaware County,” “Main Line Times” and Broad Street Review. As a former chemist, college professor and competitive weightlifter, he writes about science, education and exercise. Rutter earned a B.A. in philosophy and biology from Albright College and studied philosophy and cognitive science at Temple University.