As of 2015, there is not enough scientific evidence to establish the side effects associated with raspberry ketone supplements, according to WebMD. Raspberry ketones in food and cosmetics are generally considered to be safe.
Raspberry ketones are similar in chemical composition to other stimulants, which suggests that side effects are possible, notes WebMD. Some users of raspberry ketone supplements have reported feelings of raised blood pressure, increased heart rate and jitteriness. The appropriate dosage of raspberry ketone supplements is unknown, and it is not known if raspberry ketone supplements interact with certain drugs or foods. It is important to speak with a health care professional before taking weight loss supplements.
Raspberry ketones are chemicals that occur naturally in raspberries, and they are often used to add raspberry scent or flavor to foods and cosmetic products, as WebMD explains. While some people believe that raspberry ketones promote weight loss, experts do not substantiate this claim.
One minor study showed that people who took 200 milligrams of raspberry ketones alongside 1,200 milligrams of vitamin C for one month dropped body fat and weight, but it is not known if the weight loss was due to the raspberry ketones, the vitamin C or the combination of both, according to WebMD. Experts recommend diet and exercise as a safe and effective way to lose weight.