Professor Joseph Knoll advises 5 mg of deprenyl weekly for healthy aging after the age of 40. Deprenyl has proven to extend the lifespan in multiple animal models. Deprenyl increases the lifespan of Wistar-Logon rats, Fischer-344 rats, F344/DuCrj rats, B6D2F1 mice and dogs. However in one animal model the Wistar rat, deprenyl decreases lifespan. But in this animal model a higher dose of deprenyl was used than in the other test animals.
Deprenyl extends the lifespan of rodents when injected subcutaneously three times a week at a dose of 0,25 mg/kg body weight. The remaining life span of 24-month old Wistar-Logon rats treated with this dose of deprenyl increased from 36 to 50 months. In this study 132 Wistar-Logon rats were used. The remaining life span of 24 month old Fischer-344 rats treated with the same dose of deprenyl increased by 16%. Fischer-344 rats have a normal life span of 28 months. The life span of male and female F344/DuCrj rats treated with this dose of deprenyl increased by 8.1% and 6.7% respectively. The life span of male and female B6D2F1 mice treated with this dose increased by 6-9%. The experiment started when the male and female B6D2F1 mice had a mean age of 26 and 18.5 months, respectively.
Deprenyl increases mortality in Wistar rats when injected subcutaneously three times a week at a dose of 0,5 mg/kg body weight. Forty rats were used in this rodent study. The duration of the study was 20 months, at the end of the study the animals were euthanized. Some animals were euthanized because of tumor growht. These euthanized animals were included in the data analysis of the experiment.
Ruehl et al. reports the influence of deprenyl on the life span of dogs. This study used 41 pairs of dogs that weighted between 6.3 and 15.8 kg. The dogs used in the study were between 2.8 and 16.4 years old. The dogs were given 1 mg/kg deprenyl daily orally or placebo. The duration of the treatment was 2 years and 10 weeks. The younger dogs had to be excluded from the analysis of the survivorship data, because they were still alive until the end of the study as expected. To answer the question or daily deprenyl administered in old age increases the life span of dogs as reported in rodents, the survival of old dogs was studied. These dogs were between 10 and 15 years old at the start of the experiment. They were treated with deprenyl for at least 6 months. In these old dogs treated with deprenyl, survival was significantly extended (p<0.05) compared to the placebo group. 80% of the deprenyl treated old dogs survived until the end of the study, whereas only 39% of the old dogs in the placebo group survived the study period. It can be concluded that an oral dose of 1 mg/kg deprenyl extends the life span of old dogs.