It is thought that Salacia oblonga acts in a similar way to diabetes medications by binding to intestinal enzymes called alpha-glucosidases, which are responsible for breaking down carbohydrates into glucose. When the enzyme binds to the herbal extract rather than a carbohydrate, less glucose gets into the blood stream, resulting in lowered blood glucose and insulin levels.
After this report, please be careful about self-dosing. Herbs are not usually regulated like drugs, so I know they are accessible. Just BE CAREFUL if you purchase this stuff online before more studies come out. (There have been a slew of cases of bad botox, and this could follow suit.)
I'm sure the testing of the efficacy won't be that far away since it isn't a drug, and this way they will be able to tell what dose, if any, is best for you. It also gives time for reliable manufacturers to add it to their product list.
I'd wait for it to show up on some reputable vendor sites. I'm assuming if it does prove to work like the initial study that Costco or BJs will carry it. They have some of the best quality vitamins and fish oil pills, and their prices are first rate.