Ever since Dr. Oz promoted raspberry ketones on his show back in 2012, they’ve been all the rage, hailed as the biggest fat-burning miracle supplement.
You’ve likely seen the Google ads, the advertisements on TV and the online “testimonials” talking about the amazing weight loss benefits and heightened energy levels that come from raspberry ketones.
But how true is all of this, really? And do these raspberry ketones have anything to do with real ketosis?
Here’s the hard truth: Raspberry ketones are pointless when it comes to ketosis.
You’ll discover why below. But first, we’ll help you understand what they are and what they claim to do.
What are Raspberry Ketones?
In its true form, a raspberry ketone is found naturally in trace amounts in red raspberries and other fruits like blackberries, cranberries and kiwis. It’s what gives berries their appealing scent and flavor.
Before being sold as supplements, raspberry ketones were mostly used within the food industry, sold in items like ice cream and soft drinks, and in perfumes and cosmetics.
How Do Raspberry Ketones Work?
The claim is that raspberry ketones help your body burn fat faster and more effectively because they supposedly increase levels of adiponectin — a hormone that regulates metabolism and blood sugar levels.
Adiponectin has been shown to aid hair growth, contribute to fatty acid breakdown and regulate glucose levels[*]. This inadvertently led to raspberry ketones being sold as a weight loss product.
Here’s the theory: Adiponectin typically increases when you lose weight[*]. Those with low levels of the hormone tend to have a higher risk of suffering from type 2 diabetes, obesity, heart disease and fatty liver disease[*][*]. Supplementing with adiponectin would (theoretically) cause a loss in body weight and body fat.
Also, the molecular structure of raspberry ketones resembles molecules that have been shown in studies to boost metabolism: synephrine, a stimulant; and capsaicin, a component in chili pepper[*][*]. The claim here is that raspberry ketones can also boost metabolism because of the similarities.
However, there are problems with these claims, which you’ll dive into below.
The Difference Between Exogenous Ketones and Raspberry Ketones
Individuals take raspberry ketones for the same reason they take exogenous ketones: to get into ketosis quickly (initially), or to get back into ketosis.
Supplementing with ketones also helps athletes (who may consume more carbohydrates for performance) get the full benefits of ketosis. Finally, when just starting the keto diet it might lessen the effects of keto flu.
Raspberry ketones and exogenous ketones share these common goals. Therefore, there is quite a bit of confusion surrounding the two. Before we dive into differences — both in definition and scientific research — let’s review what exogenous ketones are.
What are Exogenous Ketones?
There are three different types of ketones your body produces in the absence of carbohydrates: Acetoacetate, beta-hydroxybutyrate and acetone. Beta-hydroxybutyrate (BHB) is the active form that can flow freely in the blood and be used by your tissues.
Exogenous ketones are ketones that are produced outside your body, in supplement form. Exogenous ketones are a tool to get you into ketosis. They can also help with the following situations:
Getting Back into Ketosis
If you eat a meal filled with carbohydrates, supplementing with exogenous ketones can help you get back into ketosis faster. The results are typically within hours, if not less.
Getting into Ketosis for the First Time
If you are starting keto for the first time, you may experience what has been dubbed, “Keto flu.” These are adverse side effects that range in symptoms from nausea, difficulty concentrating, headaches and other flu-like symptoms. Supplementing with ketones typically lessens the impact of these symptoms.
Performing Athletically on Ketosis
Some athletes find it difficult to completely cut out carbs, due to their high-impact training. Therefore, athletes can supplement with exogenous ketones to get the full benefits of ketosis while eating a higher percentage of daily carbs.
Exogenous ketones are not a weight loss supplement; they simply help your body become more efficient at using fat for energy.
The Different Forms of Exogenous Ketones (That Work)
The following are common forms of exogenous ketones, all of which are more effective (as you’ll read later on) than raspberry ketones.
The raw ketone (typically BHB) which is not bound to another compound. Typically, these can be utilized more quickly, helping to raise ketone levels in the blood. Gastric distress can be a side effect.
A ketone body is typically bound to sodium, calcium, magnesium or potassium. While it may not be as effective at raising ketone levels, it’s much easier on your digestive system.
MCT (medium chain triglyceride) oil, and other medium to smaller chain fats, can be used to help boost ketones. MCTs are broken down in the cells, indirectly creating ketone bodies.
Why Beta-hydroxybutyrate (BHB) Is the Most Efficient Ketone
As stated earlier, beta-hydroxybutyrate (BHB, 3-hydroxybutyric acid or 3-hydroxybutanoic acid) is one of the three ketone bodies produced by your body. It’s almost the most commonly found in the blood, making up to 78% of total ketones in the blood[*].
Your body uses two forms of BHB: endogenous and exogenous. Endogenous is the type of BHB it makes on its own. Exogenous BHB is the kind you supplement with, typically in the form of salts or esters (as mentioned above).
Endogenous BHB is derived from acetoacetate (AcAc) and is the main ketone used for energy. Unlike acetone, which can be lost through sweat and exercise, BHB is stable and in greater supply within your body.
Your body can use any of the three ketones for energy, but BHB is the most efficient. BHB has been shown to assist in the following:
- Reduce inflammation[*]
- Slow tumor progression and help fight cancer[*]
- Improve insulin sensitivity[*]
- Boost metabolic functions and heart health[*]
- Increase athletic performance[*]
- Enhance cognitive function and memory[*]
- And even increase your lifespan[*]
It’s also a more efficient energy source than glucose. The physical and mental benefits of BHB are undeniable.
To get more BHB flowing through your blood, follow a strict ketogenic diet, experiment with intermittent fasting and supplement with exogenous ketones and MCT oil. While your body produces endogenous BHB naturally, exogenous ketones boost your ketone levels faster. In fact, supplemental BHB can boost your ketone levels in a single hour.
Scientific Research on Raspberry Ketones
Here’s the main issue with scientific research on raspberry ketones and human weight loss: There is none.
There are absolutely no human studies showing a ketogenic benefit from taking raspberry ketones. Those selling these supposed weight loss supplements will cite a few studies with rats and mice to bulk up their credibility, but they aren’t as impressive as they’d have you believe. Here are some examples:
- In one study, fat cells were isolated from rats and grown by researchers in a test tube with raspberry ketones added[*]. This made the cells release more adiponectin and increased the breakdown of fat, but this doesn’t demonstrate that the same could happen in a living human or even a living rat.
- Another study involved feeding mice an unhealthy high-fat diet for six weeks. Some were given raspberry ketones while others weren’t. At the end of the six weeks, the mice given the raspberry ketones weighed 50 grams while those not given the ketones weighed 55 grams. The supplements actually caused weight gain. The first group simply gained 10% less than the second group[*].
- In another study, 40 rats were given a fattening diet along with raspberry ketones. Their adiponectin levels increased, but they were given the raspberry ketones in abnormally high amounts — over 100 times a feasible (or likely safe) amount for a human to take at all, much less on a regular basis[*].
There are better, more natural ways to increase the presence of adiponectin in your body and reduce fat, like eating a very low carb diet, getting regular exercise and even drinking caffeine found in green tea and coffee.
Raspberry Ketones Have Nothing to Do With Promoting Ketone Levels
For a complete breakdown of the types of ketone supplements available on the market, check out the Perfect Keto guide to ketone supplementation. An entire category is dedicated to phony ketone supplements that don’t actually improve your ketosis.
Most Raspberry Ketone Products Aren’t Legitimate Ketone Supplements
Most versions you’ll find of raspberry ketone supplements are made with artificial flavoring agents. It’s much more difficult to find real raspberry ketones. In fact, most of the supplements you’ll find use mostly ground up anise seeds, combined with a touch of real raspberry ketone.
In fact, before the Dr. Oz show, there were only a few people making a supplement with real, natural raspberry ketone powder due to the high cost of ingredients. Most have to use fillers and fake ingredients to keep the supplements affordable.
The Long-Term Effect of Raspberry Ketones is Unclear
Unlike human ketones, which can be found in supplement form (which actually benefit the ketosis process), you can’t be completely sure raspberry ketones are safe to consume. They were recognized by the U.S. Food and Drug Administration as a “Generally Recognized as Safe” food additive. However, that occured back in the 1960s — before people viewed them as a fat burner supplement.
Raspberry Ketone Bottom Line: They Don’t Have Anything to Do With Ketosis
Even though they sound fancy and contain the word “ketones,” raspberry ketones really have nothing to do with entering ketosis or burning fat mass. It’s easy to get pulled into the appeal of the product due to the name’s association with the fat-burning and health benefits of a low carb diet. However, these ketones are completely different than those made by your body, so they have no relation to ketosis or the ketogenic diet.
Even if you weren’t trying to emulate ketosis and just wanted to use raspberry ketones to lose weight, you would be left with nothing more than a much lighter wallet and disappointing results.
If you are looking for a quick boost to get into ketosis, purchase exogenous ketones. However, before you go shopping online, do your research. Exogenous ketones are a tool to get you into ketosis; not a weight loss supplement. Exogenous ketones come in the form of ketone salts, ketone esters and oils such as MCT oils. The best exogenous ketones are those which help raise BHB levels in the blood. BHB is the most abundant ketone, and more efficient than glucose for energy.
Best bet: Don’t waste your time or money on raspberry ketones. Put your energy into following a healthy, ketogenic diet for real results, and only spend your hard-earned dollar on quality ketone products (like Perfect Keto Base) that are proven to further your health goals.
Dr. Anthony Gustin is a board-certified sports chiropractor, functional medicine practitioner, entrepreneur, podcast host, and founder of Perfect Keto.
After growing his sports rehab and functional medicine clinics to six locations in San Francisco, he shifted his mission to help as many people as possible achieve optimal health and well-being.