Raspberry ketones supplements are advertised as a weight-loss aid, and claim to help people burn off excess fat, according to WebMD. There is insufficient scientific evidence to support raspberry ketones as a weight loss aid as of 2015.
Raspberry ketones are molecules that occur naturally in raspberries and help produce the raspberry's distinct taste and aroma. These molecules are sometimes used as a flavoring and scent additive in products such as packaged candy, soaps and candles, notes LiveScience. Raspberry ketones have a similar molecular structure to capsaicin, a molecule found in hot peppers that some researchers believe has the potential to increase fat metabolism in humans.
Studies performed on lab rats have shown a possible correlation between consumption of raspberry ketones and increased fat-burning metabolism, reports Authority Nutrition. In one study, isolated rat fat cells broke down more quickly and released more of the blood-sugar regulating hormone adiponectin when exposed to raspberry ketones. In another study using live mice, two groups of mice were fed a high-fat diet. The group of mice that was given raspberry ketones weighed an average of 10 percent less at the end of five weeks than the group that was not given raspberry ketones. However, the dosage of raspberry ketones given to the mice in this study was 100 times the recommended dosage in humans.