Pycnogenol, the tradename for French maritime pine tree bark, protects you from deep vein thrombosis (DVT) and superficial vein thrombosis (SVT). Both are conditions associated with prolonged air travel. The study subjects took 200 mg Pycnogenol before flying, 200 mg in mid-flight and 100 mg the day after flying. Air travel lasted an average of eight hours and 15 minutes. Compared to a placebo, researchers concluded Pycnogenol supplementation was effective in protecting against DVT and SVT in moderate to high-risk subjects.