The May 30th issue of HerbClip, a publication of the American Botanical Council, describes the horrible situation revolving around extracts of Grapefruit seed. As it turns out, there are few products if any that actually contain what the label says they are supposed to contain. The marketing of most Grapefruit seed extracts is a sham.
Grapefruit seed extract has been promoted over the years as a product with a very strong antimicrobial effect -- one that can heal a variety of diseases. It has also been considered an up-and-coming natural preservative for food and dietary supplements. Many of these claims appear to be true -- the problem is that most products sold in this category have bogus ingredient lists.
Many studies show that Grapefruit seed extracts are often adulterated with other antimicrobials, and they do not have much of the promised Grapefruit in them at all. One study referred to in the HerbClip article showed that 7 out of 9 of the products tested contained traditional antimicrobial preservatives.
There have been adverse events reported that deal with these adulterated Grapefruit seed extracts. For example, an interaction with the drug warfarin resulted in a man and woman in serious medical difficulties within three days of ingesting the adulterated extracts. Of the three brands of Grapefruit seed extract these two were taking, two showed no traces of Grapefruit seeds at all (one of the labels said 33% and another said it contained 100% Grapefruit seed extract). Based on the drug interaction with warfarin, we're not even certain that Grapefruit seeds had anything to do with the medical issues because these products contained little to none.
Luckily for us all, there are few products in the dietary supplement industry which have this same record of shame. Always buy from a reputable company, one that is known to be a supplier of quality-controlled extracts.