Durobolic is a fast-acting form of nandrolone. Nandrolone is chemically related to the male hormone testosterone. Compared to testosterone, it has an enhanced anabolic and a reduced androgenic activity. Nandrolone has been shown to positively influence calcium metabolism and to increase bone mass in osteoporosis. In women with disseminated mammary carcinoma, nandrolone has been reported to produce objective regressions for many months.

Furthermore, nandrolone has a nitrogen-saving action. This effect on protein metabolism has been established by metabolic studies and is utilised therapeutically in conditions where a protein deficiency exists such as during chronic debilitating diseases and after major surgery and severe trauma. In these conditions, nandrolone phenylpropionate serves as a supportive adjunct to specific therapies and dietary measures as well as parenteral nutrition, due to it's faster acting nature nandrolone phenylpropionate is preffered in situations where a faster clinical response is required over it's chemical variant nandrolone decaonate.

Usual dosage for Nandrolone Phenylpropionate for osteoporosis is around 50-100 mg per injection, or a total of 150-300 mg/week with the 1-2 ml injections, which are more pleasant than 2-4 ml injections. Because Durobolic is of higher concentration a smaller injection is used meaning there is less risk of infection and the experience is generally more comfortable.