Raspberry ketones are chemicals from red raspberries that are used for their flavor and fragrance. Although some supplement companies claim that raspberry ketones promote weight loss and increase lean body mass, there really isn’t enough scientific evidence that proves these claims to be true, at this point in time.
Are raspberry ketones just another element of a fad diet, or can they actually help you to lose those extra few pounds you’ve been working on? You may be struggling to lose weight and tempted to turn to supplements that claim to make a difference.
Unfortunately, we don’t really have a clear answer to that question just yet. But what we do know is that in studies conducted on rodents and in labs, only very high doses of raspberry ketones were effective for weight loss. These doses may not even be safe for humans.
So are raspberry ketones worth all the fuss or should we ignore the hype?
What Are Raspberry Ketones?
Ketones are natural chemicals that give raspberries their enticing aroma. They are phenolic compounds that also occur in berries like blackberries, cranberries, and other fruits. Although raspberry ketones have been used to add fragrance and flavor to foods and products like colas, ice cream, cosmetics, candles, soaps and candies for many years, they have recently gained attention for their alleged ability to help with weight loss.
The raspberry ketone is actually one of the most expensive products used in the food industry — the natural compound can cost as much as $20,000 per kilogram. Plus, extraction of pure raspberry ketone requires an insane amount of raspberries. Extraction occurs through hydrogenation and takes about a kilogram of raspberries (over 2 pounds) to make 1.4 milligrams of raspberry ketones. Considering a standard supplemental dose for humans is around 100–200 milligrams, that’s a lot of raspberries! This is exactly why some supplement companies use synthetic raspberry ketone, which is much cheaper. (1)
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.
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.
Benefits and Uses
1. May Aid Weight Loss (or May Not)
To date, there is not one single study that evaluates the efficacy of raspberry ketones for weight loss alone in humans. There are some studies involving rodents that have mixed reviews, but suggest that raspberry ketones may help to reduce food intake and thereby promote weight loss.
A 2005 study published in Life Sciences evaluated whether or not raspberry ketones help prevent obesity and activate lipid metabolism in rodents. The results of this study suggest that raspberry ketones prevent the high-fat-diet-induced elevations in body weight as well as the weights of the liver and visceral adipose tissues. (3)
One human study that includes raspberry ketones and other ingredients for weight loss shows promising results. The Journal of the International Society of Sports Nutrition published a randomized, placebo-controlled, double-blind study that evaluated 70 obese but otherwise healthy women who participated in an eight-week weight-loss program. The women were given a multi-ingredient supplement containing primarily raspberry ketone, caffeine, capsaicin, garlic, ginger and citrus aurantium.
The program consisted of daily supplementation, a calorie-restricted diet and exercise training. Forty-five women completed the study after eight weeks, and significant differences were observed in body weight, fat mass, lean mass, hip girth and energy levels. The placebo group did benefit from the diet and exercise portion of the program as well, but the weight loss percentages were lower than the group who took the multi-ingredient supplement.
Although this supplement containing raspberry ketone was beneficial in this study, it’s impossible to know if it was the ketones or another ingredient in the supplement that made the difference. Of the six primary ingredients, any of them could have led to weight loss during this program. (4)
So here’s what we know about raspberry ketones and their benefits for weight loss: very little. When tested in labs and on rodents, raspberry ketones seem to aid weight loss and activate fat metabolism.
However, the ketones are highly concentrated in the lab studies and dosages are extremely high in the rodent studies, so it’s impossible to equate these findings to the efficacy of ketones for actual human consumption. Before we can make a clear recommendation for using raspberry ketones for weight loss, we need a lot more research, specifically involving humans using ketones alone.
2. May Reduce Inflammation of the Liver
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.
The issue with these studies involving rodents is that the doses are very high; in fact, the equivalent dose in humans is 100 to 300 milligrams a day, which is over 200 times greater than the average daily intake of raspberry ketones! This is a worrisome dosage, especially when compared to other fat-burning supplements that are on the market today. So although this study suggests that raspberry ketones may help to reduce liver inflammation, more studies need to be done on humans using the appropriate dosage. (5)
3. May Improve Cholesterol Levels and Insulin Resistance
A 2018 study found that raspberry ketones may have a therapeutic role in controlling hyperlipidemia and insulin resistance among obese rats. Again, this is an animal study and the ketone doses were 250–500 milligrams per kilogram of body weight, which would be a very high dose for humans. (6)
The study does suggest, however, that raspberry ketones contribute to the upregulation of AQP7 expression, which is protein that plays a role in metabolic function. Like most of the potential raspberry ketone benefits, more research is needed on this to indicate whether or not ketones are effective for normalizing cholesterol levels and insulin resistance in humans.
4. Increases Hair Growth
Researchers in Japan indicate that raspberry ketone has a structure similar to that of capsaicin, the molecular compound that’s found in spicy peppers. It’s believed that like capsaicin, raspberry ketones activate sensory neurons, thereby promoting hair growth by increasing dermal insulin-like growth factor-1 (IGF-1) expression.
A study on mice found that when 0.01 percent raspberry ketones were applied topically, it increased IGF-1 expression at the surface of hair follicles and promotes hair regrowth in mice at four weeks after application.
When researchers tested whether or not raspberry ketones work as a natural treatment for thinning hair on humans, they also found positive results. When raspberry ketone was applied topically to the scalp, it promoted hair growth in 50 percent of humans with alopecia at five months after applications. (7)
5. Improves Skin Elasticity
The same researchers in Japan that reported the efficacy of raspberry ketones for hair growth evaluated its ability to improve skin elasticity in humans. They found that when 0.01 percent raspberry ketone is applied topically to skin on the face, it causes increased cheek skin elasticity at two weeks after application. This was only tested on five women, but it is a bit of promising evidence offered on raspberry ketones involving humans. (8)
Traditionally, ketones found in red raspberries were used to prevent high cholesterol, diabetes and even liver cancer. Raspberries were consumed for their ketones before supplements with much higher doses were available. Raspberries were also eaten for their nutritional value.
Raspberry nutrition is quite impressive, boasting powerful antioxidants and nutrients like vitamin C, manganese, vitamin K and magnesium. Consuming raspberries is known to help reduce inflammation, boost heart health, ease arthritic pain and fight aging.
Supplements and Dosage
Raspberry ketones supplements are available in capsule form, and they are widely available online and in vitamin stores. Raspberry ketone supplement dosage ranges from 100–1,000 milligrams, once or twice daily. Naturally, you only eat about 0.42 milligrams of raspberry ketones per kilogram of bodyweight, so if you choose to take ketone supplements, you are increasing your intake by a whole lot.
The FDA warns that supplement brands tend to contain higher concentrations of raspberry ketones than what’s generally recommended and the safety of these doses hasn’t been evaluated in scientific studies.
Before you choose to use high doses of raspberry ketone supplements, it would be best to have medical research involving humans that supports the biological effects first. There is no scientific research that evaluates the side effects of these doses on humans or the impact that they have on human cells and organs.
How to Get Raspberry Ketones in Your Diet
You can get ketones in your diet by eating berries (including raspberries, blackberries and cranberries) and fruits like kiwi, apples, grapes and peaches. Raspberry ketones are also commonly used to flavor some foods and drinks, and it’s estimated that ketones are mostly consumed through processed foods that use them as a flavoring agent.
Raspberry ketones are said to increase measures of metabolism and affect a metabolism-regulating hormone in the body called adiponectin. Adiponectin is involved in regulating glucose levels and breaking down fatty acids. It’s known for its anti-diabetic, anti-obesity and cardio-protective properties.
Some supplement companies are claiming that raspberry ketones are a great way to increase adiponectin levels, but guess what? You can boost this fat-burning hormone naturally with foods like avocados, nuts and olive oil. Drinking coffee can also increase adiponectin levels and so will exercising. (9)
Role in Ketosis/Keto Diet (Plus Recipes)
Some people get confused about raspberry ketones playing a role in ketosis and being part of the keto diet. The ketogenic diet is meant to change our “fuel source” that our bodies use to stay energized. It’s a diet made up of high-fat, low-carb foods. Switching to these foods will place your body in a state of ketosis, which is when your body becomes a fat burner, instead of sugar burner.
When your body doesn’t have any glucose to burn for energy, it will burn fat and produce ketones instead. And once your blood levels of ketones reach a certain point, you are officially in a state of ketosis.
The ketones that play a role in the keto diet are made naturally within the human body. They are water-soluble molecules that are produced in the liver. The body breaks down fatty acids into ketones, which then circulate through the bloodstream and alter our metabolism so that we continue to burn fat.
When you are following a ketogenic diet plan, you should only be eating fruits like raspberries occasionally. You also want to avoid eating any processed foods that are commonly made with raspberry ketones.
The ketones that are naturally produced by the liver are called “endogenous ketones,” but there are also “exogenous ketones” that are provided from outside the body and used in many keto supplements to raise ketone levels in the body. These ketones, which are also called keto salts, are completely different than raspberry ketones. Raspberry ketones don’t raise ketone levels in the body and they don’t mimic endogenous ketones, so you wouldn’t use raspberry ketones as part of the keto diet.
Risks, Side Effects and Interactions
Raspberry ketone supplements may cause side effects including rapid heart beat, increased blood pressure and jitteriness. They may also lower blood sugar levels and interact with medications used to control your heart rate, blood sugar, cholesterol and hormones.
There is not enough research to clarify whether or not raspberry ketones are safe for women who are pregnant or nursing, so they should avoid using these types of supplements.
If you choose to use raspberry ketones, I recommend consulting with your healthcare provider first. Remember that the supplement dosage is likely much higher than the amount of ketones you would ever consume naturally, and the science of the safety of these doses is extremely limited.
- Raspberry ketones are natural phenolic compounds found in raspberries, other berries and some fruits. Traditionally, raspberry ketones have been consumed for their anti-diabetic and cholesterol-lowering properties, but more recently, they have gained popularity for their potential ability to help with weight loss.
- The evidence of raspberry ketones for weight loss is minimal. Most studies involve rodents or single cells in labs. There is some evidence that raspberry ketones can help to promote hair growth and improve skin elasticity in humans.
- Here’s the bottom line: There are a lot of companies that claim to have the new magic pill. Weight-loss supplements are popular because they don’t require work. The truth is there is no magic pill. To lose weight and stay healthy, it’s best to eat a well-rounded diet, and you can rely on fat-burning foods that have been consumed by humans for thousands of years.
- It’s only with daily physical activity and healthy lifestyle choices that you can, for example, lose 20 pounds in 30 days. The interest in raspberry ketones is out there, and there has been an increase in scientific research. Hopefully more evidence involving human experiments will clear up this controversial topic, but for now the results are unclear.