The leading drug prescribed for male impotence can counteract the lethargy caused by a disruption in the sleep cycle, a study in rodents suggests. Sildenafil, commonly known as Viagra, helps hamsters rebound from a 6-hour clock change such as a long eastbound plane flight produces.
To mimic conditions that can lead to jet lag, scientists habituated hamsters to a daily routine of 14 hours of light and 10 hours of darkness. The researchers then abruptly switched on the lights 6 hours early and continued the same light-to-dark routine from that point onward, simulating the effects of a flight from Chicago to London.
Just before changing the hamsters' routine, the researchers injected each animal with either sildenafil or saline solution. Then, they observed how long it took the hamsters to restart their daily habit of running on a wheel.