Raspberry ketone is an aromatic compound found in raspberries. This chemical is what gives raspberries their characteristic aroma and is also found in blackberries and cranberries. It is used in natural and artificial flavorings, cosmetics and nutritional supplements.
Raspberry ketone is a popular weight-loss supplement. Studies show weight loss effects in rats fed large doses of the chemical, but this effect is not proven in humans. While it is an approved food additive and has been generally recognized as safe since 1965, there is no data on its long-term effects in the doses necessary to produce weight loss in rats. Rats in studies show no long-term harm from doses 238 times higher than the average human intake of raspberry ketone, suggesting that it is safe.
In addition to its use in weight loss products, raspberry ketone is a food and perfume additive. Both natural and artificial versions of raspberry ketone are used to add raspberry flavor and scent to products. Artificial formulas are popular due to the high cost of natural raspberry ketone. Because 1 kilogram of raspberries produces only 1 to 4 milligrams of raspberry ketone, the price of natural raspberry ketone can be as high as $20,000 per kilogram as of 2014.