Pycnogenol is far from cheap and not all the pycnogenol supplements are of the same quality, Maybe-for this reason-it could be reserved for long flights and for people who had DVT and those who had etinal vein thrombosis c

French Maritime Pine Bark Extract (Pycnogenol)[article from LifeExtension]

Pycnogenol, an extract from French maritime pine bark, has been reported to prevent edema and venous thrombosis during long airplane flights and may help chronic venous insufficiency.145,146 In one controlled trial, 198 airline passengers with moderate to high risk of venous thrombosis were given either pycnogenol, at 200 mg before and during a long flight (averaging 8 hours 15 minutes) plus 100 mg the next day, or placebo. There were five venous thrombotic events in the placebo group and none in the pycnogenol group.147

In a randomized controlled trial in 156 subjects with a history of a single DVT episode, 150 mg pycnogenol was as effective as compression stockings at reducing edema after one year, but was associated with better compliance due to the discomfort of compression stockings.148 In an observational study that followed 222 subjects with a history of DVT for six years, those taking 200 mg pycnogenol per day had lower risks of recurrent DVT and post-thrombotic syndrome compared with those treated with blood thinner medications such as aspirin, ticlopidine (Ticlid), sulodexide (Aterina, a formulation composed of 80% low-molecular weight heparin), or no medication.149 Pycnogenol has also been found to improve arterial endothelial function by increasing nitric oxide production in healthy subjects and those with coronary artery disease.150,151 One research team found a dose of 200 mg pycnogenol per day for two months suppressed the smoking-induced rise in platelet aggregation in chronic smokers but had no effect on platelet aggregation in non-smokers.152

Observational evidence from a study in 307 subjects with a history of retinal vein thrombosis found taking 100 mg pycnogenol daily was associated with the lowest incidence of repeat retinal vein thrombosis compared with aspirin, ticlopidine, sulodexide, or no medication, and was the only treatment associated with reduction in edema.153 A smaller study of similar design found pycnogenol, at 100 mg daily, was associated with better vision, lower risks of retinal edema and recurrent retinal vein thrombosis, and lower frequency of adverse side effects compared with aspirin after nine months.154