I have tried mangosteen juice, it is rich in naturally occuring vitamin c and antioxidents. But it is not the richest source. but it is a good start and it tastes good, just dont go overboard on it because it has a tendency to move the bowels. Its kind of expensive for what your getting. I paid 30 dollars for a bottle but you do get what you pay for with natural health products. Just look at what else is in the bottle. any preservatives and additives totally negate the benefits