Raspberry ketone is a phenolic compound that is extracted from fruit. Phenolic compounds are a type of organic chemical - most of them have a characteristic sweet fragrance. It is of course found in raspberries (hence the name), but it is also found in other fruits including blackberries and cranberries.
This compound is chemically similar to capsaicin (found in chili peppers) and synephrine (found in bitter orange extract). Previous research studies on those substances suggested that they might improve the metabolism of fat.
Pure natural raspberry ketone is rather an expensive product - 1 kilogram of raspberries produces only 1-4 milligrams of this extract! Fortunately, organic chemists have discovered ways to reproduce it synthetically in the lab. (For all you chemistry geeks, here's a summary of the process.) The bottom line is that synthetic RK is an identical chemical compound which is easier to produce and much less expensive.
Many refer to it simply by the initials RK - an abbreviation we use frequently throughout this site. Chemists call it 4-(4-Hydroxyphenyl)butan-2-one. In the fragrance and flavoring industries, it is sometimes known as Rheosmin or Frambinone ("the smell of raspberries.")
Contrary to what you might read elsewhere, a recent clinical study was conducted on humans. See our page on weight loss for details on the study and its results.
Research suggests that raspberry ketone has properties which act on fat cells and your metabolism, and can help you lose weight.
It helps increase your levels of two substances - adiponectin, which regulates your metabolism, and norepenephrine, which accelerates the breakdown of fat.
Raspberry ketone appears to increase the secretion of the hormone adiponectin - a protein which regulates your metabolism. Low levels of adiponectin are associated with higher amounts of body fat.
It is generally considered safe for most healthy adults. However, long-term safety data is lacking - if you have any concerns you should ask the opinion of a medical professional.
It can cause anxiety and restlessness. One study reported mild, temporary stomach discomfort.
Since RK affects both adiponectin (which lowers blood glucose) and norepinephrine (which can raise it), there's a possibility that it may affect your ability to manage your glucose levels. Please talk to your doctor.
While RK does not appear to cause hypertension in healthy adults, it acts like a stimulant and can elevate blood pressure in people who are prone to hypertension. If you have high blood pressure or heart disease, you are strongly advised to check with your doctor before starting this supplement.
Because it can cause anxiety, raspberry ketone is not recommended if you are being treated with anti-anxiety medicines. There is no research on how raspberry ketone may interact with other prescription or non-prescription drugs. If you are taking any medication, we recommend you check with your doctor.
There has been some speculation that long-term use of RK may temporarily interfere with thyroid function. We were unable to find any evidence or studies to support this.
There are no studies on this. Please ask your doctor.
Studies indicate that it might protect against the development of fatty liver disease, caused by a high fat diet.
Early research suggests that it may have potential for use as a topical product to:
Raspberry ketone is also widely used in the fragrance and flavoring industries.
Read the product label. As little as 100mg is considered an effective dose. Most supplements have more than that - often 150-300mg per dose. Some products recommend you take as much as 800 mg - please be aware that there is no data on the safety of these very high dosages.
A clinical trial, conducted on 70 overweight but otherwise healthy individuals, showed measurable results in the group taking a raspberry ketone combination supplement by the end of 8 weeks.
None. The Doctor Oz Show never endorses any particular brand of product.
Read our buyers guide and check out comparisons and star ratings of 10 of the bestselling raspberry ketone supplements