Nandrolone Other names: Decanoate nandrolone 19-nortestosterone

Nandrolone is chemically related to testosterone and shows enhanced anabolic and a reduced androgenic activity.

In humans nandrolone has been shown to positively influence calcium metabolism and to increase bone mass in osteoporosis.

Androgenic effects (e.g. virilisation) are relatively uncommon at the recommended dosages. Nandrolone lacks the C17 alpha-alkyl group which is associated with the occurrence of liver dysfunction and cholestasis.

Absorption

Nandrolone decanoate is slowly released from the injection site into the blood with a half-life of 6 days.

Distribution

The ester is rapidly hydrolysed to nandrolone in the blood with a half-life of one hour or less. The half-life for the combined process of hydrolysis of nandrolone decanoate and of distribution and elimination of nandrolone is 4.3 hours.

Biotransformation and excretion

Nandrolone is metabolised by the liver. 19-norandrosterone, 19-noretiocholanolone and 19-norepiandrosterone have been identified as metabolites in the urine. It is not known whether these metabolites display a pharmacological action.

Toxicity studies in animals after repeated dosing did not indicate a safety risk for humans. No formal studies to assess reproduction toxicity, genotoxicity and carcinogenicity have been conducted by the company. As a class, anabolic steroids are considered to be probably carcinogenic to humans (IARC Group 2a).

The use of androgens in different species has resulted in virilisation of the external genitals of female foetuses. Investigations into the genotoxic potential of nandrolone showed it to be positive in an in vitro micronucleus assay and an in vivo micronucleus assay in mouse but not rat, and in the comet assay of mouse and rat. The clinical relevance of these findings is unknown, therefore the risk to patients cannot be ruled out.