This study will assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of MK0773 in healthy older men.

Inclusion Criteria:

• Subject is in good general health
• Subject agrees to avoid excess alcohol and strenuous physical activity during the study
• Subject who is sexually active with partners of reproductive potential agrees to use two forms of appropriate contraception during the study

Exclusion Criteria:

• Subject has significant drug allergies
• Subject has donated blood within the last 8 weeks or has taken an investigational drug in another clinical trial within the last 4 weeks
• Subject is a regular user or past abuser of any illicit drug (including alcohol)
• Subject drinks excessive amounts of caffeinated beverages
• Subject has a history of cancer
• Subject has a history of prostate or testicular surgery