Here are a couple more recent studies as well:martinleroux wrote: There have been several studies on Ginkgo biloba extract (GBE) and AMS, but with conflicting results. Here are a couple. Peter Hackett was a co-author for both of these.
Leadbetter et al (2009), "Ginkgo biloba does - and does not - prevent acute mountain sickness", http://www.ncbi.nlm.nih.gov/pubmed/19364166
"Two randomized, double-blind, placebo-controlled cohort studies were conducted... Ginkgo biloba reduced the incidence and severity of AMS compared to placebo in the first but not the second study... The primary difference between the 2 studies was the source of GBE... The source and composition of GBE products may determine the effectiveness of GBE for prophylaxis of AMS".
Tissot van Patot et al (2009), "Ginkgo biloba for Prevention of Acute Mountain Sickness: Does It Work?", http://www.ncbi.nlm.nih.gov/pubmed/19278351
"We review the current literature regarding the prophylactic use of Ginkgo biloba extract (GBE) in acute mountain sickness (AMS)... Overall, the literature suggests that due to the complexity of GBE the standardization of the product is inadequate, which likely explains the disparate clinical results. The variability in commercially available GBE products makes it impossible to determine whether GBE is truly effective for preventing or ameliorating AMS".
"Pharmacologic prophylaxis for acute mountain sickness: a systematic shortcut review." (2012) - (http://www.ncbi.nlm.nih.gov/pubmed/22153998" onclick="window.open(this.href);return false;)
"Antioxidants, magnesium, and G biloba were not efficacious"
"Effect of acetazolamide and gingko biloba on the human pulmonary vascular response to an acute altitude ascent." (2013) - (http://www.ncbi.nlm.nih.gov/pubmed/23795737" onclick="window.open(this.href);return false;)
"The data show that a low prophylactic dosage of acetazolamide, but not gingko biloba, mitigates the early increase of PASP in a quick ascent profile."
For anyone interested, I have the full text on all four of these studies. PM me directly if you want them.