Raspberry ketone is marketed as a weight loss aid that you can find in most any store that carries dietary supplements. It’s an aromatic compound found in red raspberries that is extracted and used in perfumes and cosmetics, and it’s also used as a flavoring agent in some fruit-flavored foods.
Structurally, raspberry ketones are somewhat similar to that of synephrine and ephedrine, two substances that are used for weight loss. Raspberry ketones also have some structural similarity to capsaicin, which is known for its pain-relieving and anti-diabetic properties.
Raspberry ketone is a chemical from red raspberries, as well as kiwifruit, peaches, grapes, apples, other berries, vegetables such as rhubarb, and the bark of yew, maple, and pine trees.
People take raspberry ketone by mouth for weight loss. It became popular for weight loss after it was mentioned on the Dr. Oz television show during the segment called “Raspberry ketone: Miracle fat-burner in a bottle” in February 2012.
People apply raspberry ketone to the skin for hair loss.
Raspberry ketone is also used in foods, cosmetics, and other manufacturing as a fragrance or flavoring agent.
Some research in rodents and test tubes shows that raspberry ketones might increase measures of metabolism and affect a hormone in the body called adiponectin, which regulates metabolism. Raspberry ketones are claimed to cause the fat within cells to be broken down more effectively, which helps the body burn fat faster.
Here’s the problem: there are no human studies on raspberry ketones alone for weight loss and the studies that are done in labs or with rodents involve very high doses of ketones.
Raspberry ketone supplements exhibit promise in studies on mice and rats.
However, the results weren’t nearly as impressive as the supplement manufacturers would have you believe.
In one study, raspberry ketones were given to some mice fed a fattening diet (17Trusted Source).
The mice in the raspberry ketone group weighed 50 grams at the end of the study, while the mice that didn’t get ketones weighed 55 grams — a 10% difference.
Note that the mice fed ketones did not lose weight — they just gained less than others.
Some raspberry ketone studies have been done in laboratories. Mice were given raspberry ketone, and it appeared to prevent weight gain when the little rodents were fed high-fat diets. Apparently, the anti-obesity effects were due to stimulation of lipolysis (which is how the body breaks down fat in fat cells called adipocytes) in both regular fat tissue and brown fat tissue. It also suppressed the release of pancreatic lipase, a digestive enzyme needed to break down dietary fats so they can be absorbed through the small intestinal wall.
Natural raspberry ketone is expensive, so it isn’t easy for manufacturers to buy enough of it at a reasonable price. Most of the raspberry ketone products are artificially created from other ingredients. Don’t be fooled by the label—it may have words like “natural” and “high quality” even if the product contains only artificial raspberry ketone.
Since there’s no reliable evidence that backs up the claims that it will help you lose weight (whether your find natural or artificial raspberry ketone), you’ll still have to cut back on calories or exercise more if you want to lose weight.
One study links raspberry ketones to cosmetic benefits.
When administered topically as part of a cream, raspberry ketones appear to increase hair growth in people with hair loss. It may also improve skin elasticity in healthy women (20Trusted Source).
However, this study was small and had a number of flaws. More studies need to confirm these effects before any claims can be made (21).
A 2012 study published in the Journal of Medical Food found that raspberry ketone treatment, after a high-fat diet, can protect rats against nonalcoholic steatohepatitis, which is liver inflammation caused by a buildup of fat in the liver. Researchers reported that raspberry ketones had a dual effect of liver protection and fat reduction in the tested rats.
No studies have directly assessed the role of raspberries or raspberry ketones in humans who have dementia or have a higher risk of developing it. However, scientists have found links between raspberries and Alzheimer’s disease.
Some research has looked at how ellagic acid, a phytochemical in raspberries, affects the formation of amyloid plaques.
People with Alzheimer’s typically have these plaques in their brains, and the plaques get worse as the disease progresses.
The study showed that ellagic acid might slow the development of plaques. If this is the case, eating whole raspberries may be more beneficial than taking raspberry ketones as a supplement. However, more research is necessary to confirm this potential benefit.
Isolated case reports suggest that ketones might cause side effects similar to those of supplements. These can include:
- heart palpitations
- high blood pressure
People considering using raspberry ketones should consult a doctor first. Speaking to a doctor before taking raspberry ketones is particularly important for people who:
- have a medical condition
- take prescription drugs
- take herbal supplements
The U.S. Food and Drug Administration first categorized raspberry ketones as a “Generally Recognized as Safe” (GRAS) food additive in the 1960s. However GRAS status is given under the assumption that a person will consume less than two milligrams of raspberry ketone a day. Most weight loss supplements pack far more raspberry ketone into their products.
Raspberry ketone is not well studied at concentrations used in supplements – which can range from 50 to 250 milligram per serving. And there are some known side effects from their use.
Typical diets provide only a few mg of raspberry ketones a day. Doses contained in dietary supplements typically range from 100 to 1,400 mg, and the safety of such doses has never been evaluated in humans . Participants in the METABO study described above had no serious adverse effects . However, additional research on raspberry ketone is needed to better understand its safety and side effects.