Nandrolone is a testosterone derivative which has very marked anabolic and anti-catabolic action whilst in the recommended therapeutic dosage it has negligible androgenic or progestagenic activity. It may therefore be used in both male and female with equally safe and potent activity. Positive effects on nitrogen, calcium and phosphorus metabolism are promoted, together with normalisation of tissue water/electrolyte balance.

Laurabolin is indicated whenever excessive tissue breakdown or extensive repair processes are proceeding, particularly in convalescence, new born animals, geriatrics, tendon and bone damage and after surgery. The effects of each treatment last approximately three weeks.

After release from the intramuscular or subcutaneous depot, it has been shown that the nandrolone ester enters the peripheral circulation and is immediately hydrolysed, releasing the active substance, nandrolone. The laurate ester of nandrolone has been compared with the phenylpropionate or decanoate esters. The T1/2 for the intra-muscular depot of nandrolone laurate in the rat is 243 hours compared with 130 hours for the decanoate, 25_hours for the phenylpropionate and 0.6 hours for nandrolone. This reflects the duration of action of the esters - 1 week for the phenylpropionate, 2-3 weeks for the decanoate and 3-4 weeks for the laurate.

Excretion and metabolic studies were carried out with nandrolone in rats. 3H nandrolone and/or its metabolites were not retained or stored in the body of rats. The biological half life of the radioactivity was 1-2 days. A pharmacokinetic study was performed in dogs. The nandrolone levels rose slowly after injection, reaching peak levels after an average of 5 days. Thereafter levels decreased steadily with an elimination half life of approximately 12 days. Twenty-one days after the injections, measurable levels of nandrolone were still present. There were no differences in pharmacokinetics between male and female animals. It should be noted that the dose of Laurabolin administered (1 mg/kg) was less than the range recommended in the data sheet/package insert: 2-5 mg/kg. The plasma levels after treatment would thus have a somewhat higher peak and slightly longer duration of action.