The number of people traveling to altitude for work or for recreation is rising, and increased media attention towards these activities has also raised the profile of altitude related illness. The most effective preventive measure for acute mountain sickness (AMS)-gradual ascent-is frequently difficult or impractical for modern international travel to locations such as Lhasa in Tibet (3650 m) and La Paz in Bolivia (3740 m). In order to solve this problem, prophylactic acetazolamide was most commonly used. But prescription needed and side effects such as paresthesia and nausea are the disadvantage of using acetazolamide. Some over-the-counter herbal supplements with essentially no adverse effect were widely used, such as Rhodiola species. Rhodiola crenulata are widely used to prevent AMS in Himalayan areas and Lhasa in Tibet but none was examined by human study. The investigators conducted a randomized, double blind, placebo controlled, crossover study to investigate the efficacy of Rhodiola crenulata in preventing AMS.
Traditional folk medicine in the Arctic and Himalayan areas used Rhodiola species to enhance physical endurance, prevent aging, resist acute mountain sickness (AMS), and to treat fatigue, depression, anemia, impotence and respiratory infections. Rhodiola crenulata are widely used to prevent AMS in Himalayan areas and Lhasa in Tibet but none was examined by human study. The investigators conducted a randomized, double blind, placebo controlled, crossover study to investigate the efficacy of Rhodiola crenulata in preventing AMS.