The purpose of this study is to define the absorption, breakdown and excretion of a single dose of radiolabelled SB-649868 and its breakdown products by measuring their concentration in blood, urine and faeces over a 7-10 day period. "Radiolabelled" means that the test drug has a radioactive component to help us track the drug. The safety and tolerability of the test drug will also be assessed.

Inclusion criteria:

• Healthy males, aged 30-55 years inclusive.
• Body weight more or equal to 50kg with a BMI (body mass index) between 18.5-29.9kg/m2 inclusive.
• Healthy as based on a medical evaluation consisting of medical history, physical examination, lab tests on blood and urine and cardiovascular monitoring.

LH, FSH and testosterone hormones must be within normal reference range.

Exclusion criteria:

• Positive urine drug screen or alcohol breath test at screening visit.
• Average weekly alcohol intake of more than 21 units or average daily intake of more than 3 units.
• Grapefruit or grapefruit juice intake 7 days before dosing and until the last blood sample is taken.
• Any subject who is not prepared to eat standard meals in the clinic or is a vegetarian.
• Participated in a clinical trial for a new drug within 30 days or 5 half-lives or twice the duration of that drugs effect before the dosing day for this study.
• Exposure to 4 new drugs in clinical trials within the last 12 months before dosing in this study.
• Use of any medications (prescribed or non-prescribed including vitamins and herbal supplements) within 7 days before dosing in this study.
• Participation in this study would result in the subject donating more than 500ml in a 56 day period.
• Regular use of tobacco or nicotine-containing products within 6 months of screening.
• Unwillingness to abstain from sexual intercourse with pregnant or lactating women from dosing until 84 days after.
• Unwillingness to use contraception and have female partner use contraception if she could become pregnant for 84 days after dosing.
• Unwillingness to abstain from strenuous physical activity for 48 hours before screening and in the 72 hours before and 48 hours after the treatment period.
• Administration of radiolabelled substances or exposure to significant radiation (eg serial X-rays or CT scans, barium meal etc)within the past 12 months from screening.