Consuming exogenous ketones isn't the same as following a ketogenic diet–the ketones in the blood haven't been naturally produced by the breakdown of fat stores. However, scientists believe many of the health benefits of the keto diet and fasting (aside from weight loss) are triggered by ketones. Therefore, raising ketone levels through either endogenous or exogenous ketosis could help to improve health and performance by:

Exogenous ketones provide the body with another fuel to employ. Think about it like an electric car that runs on both gas and electricity: by consuming ketones along with carbohydrates, the body will preferentially burn the ketones first, saving the carbohydrates for later. Exogenous ketones allow us to enter a metabolic state that wouldn't occur naturally: the state of having full carbohydrate stores, as well as elevated ketones in the blood. This could be advantageous to athletes looking to boost their physical performance. 

Now that you have fasted for quite a long time, you can break your fast at around 4 to 5 pm. Try having some good fat for this purpose, such as coconut oil or MCT oil, butter, or any other healthy fat. MCT oil might come in as a better option in this case since it gets quickly absorbed by the body. It swiftly bypasses the gallbladder and reaches the liver where it is transformed to ketones rapidly.
To determine the reason for the differences in blood d-βHB concentration, the KE and KS drinks were analyzed for enantiomeric purity. The KE contained >99% of the d-isoform, whereas ~50% of the KS βHB was the l-isoform (Figure ​(Figure1D).1D). Plasma samples from participants who consumed the high dose KS drink (n = 5) were analyzed to reveal higher l-βHB than d-βHB, the total βHB Cmax being 3.4 ± 0.2 mM (Figure ​(Figure1E),1E), with a total βHB AUC of 549 ± 19 mmol.min. After 4 h, plasma l-βHB remained elevated at 1.9 ± 0.2 mM; differences in urinary excretion of the two isoforms could not explain this observation as both d- and l-βHB were excreted in proportion to their blood AUCs (Figure ​(Figure1F).1F). Therefore, in order to determine the time required for l-βHB elimination, a follow-up experiment was undertaken in which subjects (n = 5) consumed 3.2−1 of βHB as KE and KS with hourly blood and breath sample collection up to 4 h, plus additional samples at 8 h and 24 h post-drink. l-βHB was found to be 1.1 ± 0.1 mM at 4 h, and 0.7 ± 0.2 mM after 8 h, but undetectable after 24 h (Figure 1G). Low amounts of d-βHB (0.3 ± 0.1 mM) were present at 24 h, presumably due to endogenous production. Both ketone drinks significantly increased breath acetone concentration, but at a slower rate than blood d-βHB, reaching a peak after 3 h that was twice as high following the KE (87 ± 9 ppm) than the KS (44 ± 10 ppm), suggesting that d-βHB was readily converted to acetone, but l-βHB was not (p < 0.005, Figure ​Figure1H1H).
If you are new to ketosis and don’t know much about it, it is a metabolic state, where your body preferentially uses ketones (instead of glucose) for energy. This can lead to a host of different health benefits. If you’d like to learn more about ketosis, what ketones are, and how to benefit from these, feel free to read through our guides: What is Ketosis? What is the Ketogenic Diet? What Are Ketones?
The ketone supplements were associated with a 5.4% decrease in physical performance while the artificially-sweetened, non-caffeinated beverage I used as a placebo was associated with a 20.3% increase: a big difference in favour of the placebo. Before you go rushing out to buy some, remember that this experiment was not performed under fully-controlled, laboratory conditions, and we were working with too small a group to prove that the placebo caused an increase in physical performance. But what we can say is that we couldn’t find any correlation between ketone supplements and an increase in physical performance in this experiment. According to Brianna Stubbs, some of the work currently being done on new kinds of ketone salts is starting to show more promise in relation to physical performance, so there may be better news on this down the line.
A growing number of people are giving it a try, thanks to exogenous ketone supplements that claim to launch your body into a state of ketosis within two and a half days—even if you’ve been living on pasta and cookies instead of following a low-carb diet. How can that be, though? And can that kind of rapid transformation actually be safe? Here’s what you should know.
Miriam, Thank you for the questions. I am going to do my best here to provide you with answers: Q: The manufacture of BHB salts involves ionic bonding of an anion (beta-hydroxybutyrate) with a cation (Na+, K+, Ca+, Mg+). At least one of the exogenous ketone products you listed does in fact contain potassium ions. People taking potassium-sparing drugs need to know this and that raises concerns about leaving it off your chart. A: The table lists the BHB and the mineral content from the BHB salts (no added minerals). Therefore, since potassium BHB is not in any of the… Read more »
North Americans typically live pro-inflammatory, pro-disease lives (think about your everyday: likely sitting in a flexed position for hours on end, not enough natural sunlight, not enough movement, artificial food stuffs, artificial colouring, going to bed late, blue light exposure, less in-person contact with our loved ones, late night snacks, the list goes on and on).
Good question. There have been many tests and studies that have been conducted to see if ketogenic supplements genuinely do work and many of these studies have shown that ketosis theories are correct. Adding ketones to your body and using fats as a resource of energy has some fantastic effects and if done right can help your body fight all sorts of ailments such as cancer, heart disease, diabetes and many other illnesses that can only be cured by chemical therapy. Keto therapy or nutritional ketosis is paving the way for more natural solutions, and it's a good thing that scientists have created these exogenous ketone supplements that help us induce more ketones in our body.
The “BHB salt” is simply a compound that consists of sodium (Na+), potassium (K+), and the ketone body β-hydroxybutyrate. In supplements like Pruvit’s Keto OS these individual components are being held together by ionic bonds; however, when you consume the product, it is absorbed into the blood where it dissociates into free Na+, K+, and BHB since it is a water-based solution. Thus, consuming the product directly and immediately puts more ketones into your blood.
It might sound absolutely crazy to go that long without food. Especially when you consider traditional diets that recommend eating 3-5 small meals each day, starting with breakfast – the “most important” meal of the day. But if you think back to hunter gatherer times, human beings didn’t always have food accessible to us. Farming and agriculture hadn’t existed so our first meal each day would vary quite vastly. If you think about the word itself, ‘breakfast’ means to break-fast. We didn’t have a set time where we would consume our first meal – it was dependent on accessibility. So if you’re wondering how you’re going to survive without going for food for 16 hours, the answer is straight forward – you can! Let’s simplify this and break down what this may potentially look like.
I feel like I should also mention that the GI discomfort is real, people. I would recommend starting this product on a weekend or a day where you’re able to just take it easy. After my first dose, which was only 1/2 scoop, I literally just felt like lying in bed all day due to feelings of nauseousness; however, by the next day I was fine and even bumped my dose to a full scoop.
Intense exercise — more than just fidgeting or pacing — uses ketones, when glucose is in short supply, which means the body has to create more ketones to replace what you use. This is great for those who are used to a moderate to intense activity level, but intensity is a fine dance between encouraging ketone production and elevating cortisol for the rest of us.

The current recommendation for magnesium is 310-320 mg for adult women and 400-420 mg for adult men. Magnesium deficiencies are common; 2005-2006 data indicates that the majority of Americans’ dietary magnesium intake was less than the Estimated Average Requirement (EAR) for the respective age groups[25]. The EAR for a nutrient is about 20% LESS than the RDA. Current data on magnesium intake and deficiency in the US is not readily available, as magnesium testing is not part of routine electrolyte testing in hospitals and clinics[26].
Since beta hydroxybutyrate is transported throughout the body via the blood, the best way to check your true BHB levels is through a blood test. The good news is that you can just use a simple finger prick and an at home method that is very similar to how diabetics check their glucose. The bad news is that it can be pretty expensive. Each strip and time you test can be around $4-6.
Second, take a look back at table 2. Kegenix Prime scored as the “winning brand” for 4 out of the 7 markers tested: mental performance, satiety, mental clarity and energy. Compared to the other supplements, it also scored highest for physical performance, although none of the supplements were listed as a “winner” since the placebo outperformed them all for that marker.
In fact this was one of the biggest surprises I had when exploring ketosis. For years I have been following a cyclical lower carb diet. For years I wouldn’t consume a carb until later in the afternoon (ala Carb Backloading style). After eating 5 days without any carbs I tested my ketone levels… they were 0.1 mmol. This reading was done first thing in the morning (10 hours fasted) after 5 days without a carb in my diet.
Most of the ketone supplements out there are either underdosed or overpriced - some don't even bother to disclose how much BHB (ie ketones) is used in their product. And why would they? BHB is EXTREMELY expensive. So by not disclosing the amount the can get away with putting in as little as they want and still claim it's a ketone supplement while keeping their costs as low as possible.

Your body uses the energy source that is the easiest to use, in our case this is glucose. Glucose is just a type of sugar. As our body cannot store glucose as such it stores the extra glucose in form of glycogen that is stored in our liver and muscles. To initiate production of ketones in your body as fast as possible you must deplete your body of glycogen reserves. The best way to do this is a simple 24 hours fast. This will deplete your glycogen stores as fast as possible. If you don’t over eat for dinner or you even skip it all together you will already wake up in state of mild ketosis the next morning due to the overnight fast. Here are also described some signs that you are in Ketosis already.
Because they’re so expensive, you want to make sure you pick a good one. Griffin and Langer say to ignore the companies that make these supplements sound too good to be true. Just like with any supplement, Griffin says it’s important to look at what’s in it. Beware of products with lots of fillers and instead go for one with a short, straightforward list of ingredients (Griffin likes the options from KetoSports).
Ketoacidosis is driven by a lack of insulin in the body.  Without insulin, blood sugar rises to high levels and stored fat streams from fat cells.  This excess amount of fat metabolism results in the production of abnormal quantities of ketones. The combination of high blood sugar and high ketone levels can upset the normal acid/base balance in the blood and become dangerous.  In order to reach a state of ketoacidosis, insulin levels must be so low that the regulation of blood sugar and fatty acid flow is impaired.
Recently, two published studies investigated the effects of ketone salts in athletes (total n = 22).8,9 Performance over a four-minute cycling time-trial and a 150 kJ ( ~11 mins) cycling time trial were compared between ketone salts vs. carbohydrate. In the four-minute trial there was no change in performance, and in the 150 kJ test, performance decreased by 7%. Blood BHB levels peaked at 0.6 and 0.8 mM in these studies.
Studies show that exercising depletes both liver and muscle glycogen faster than fasting [4]. For example, swimming for an hour and a half depletes the same amount of glycogen as a 24-hour fast. However, it's a good idea to eat a tiny amount of carbs and protein before and after a workout to prevent muscle damage. Your body can break down proteins in your muscles if glycogen stores get depleted during workouts.
Our mission at Ketologie is to help educate and assist people in transitioning to a ketogenic way of eating for life. Primarily, we support people achieving this via adopting a VLCHF or ketogenic way of eating. Exogenous ketones can however play a useful role in transitioning to and maintaining a ketogenic lifestyle, and so we have exhaustively researched and developed a unique, “next level” ketone supplement that focuses specifically on optimizing health via the gut-brain axis.
Increased calcium levels in the bloodstream may contribute to the hardening of arteries (atherosclerosis), which in turn can lead to a heart attack.  Calcium from supplements enters the bloodstream in one bolus, whereas we usually tend to get calcium from foods in small doses from the breakdown process. This might explain why calcium from food doesn’t create the same risk that is introduced by calcium supplements. At first glance, it seems to be the case that high calcium intake –at least from supplements–may not be ideal.

So I’ve been primarily on a Keto diet for almost 6 months. During this time, I have fine tuned a lot to get my ketone levels up (Eating more fat and less protein). Most recently, I have used blood measurements for my ketone levels and I fluctuate between .6 and 2.6. The higher readings I get on the days I workout in the morning (about 5 hours before I draw blood and take a reading). I don’t have any problems sticking to the diet. It only seems to get easier. I’ve also incorporated 16 hour fasts which also are becoming easier over time. My priority and motivation for doing a keto diet is first and foremost weight loss. So far I have lost 40 pounds and I need to lose about 20 more. I do however want to improve my performance (running) and strength (I am doing the Stronglifts 5×5 program now).
If you noticed that you're not getting into ketosis quick enough, chances are you're not eating enough fat. Eating plenty of healthy fat is essential in inducing ketosis. One reason why this is so is that your body makes ketones from fat. The other reason being that fat is highly satiating, so your body won't slow down or start breaking down muscle for fuel.

Exogenous ketones don’t seem to improve high-intensity, glucose-intensive exercise, increasing fat burning during steady state exercise but dropping top-end high-intensity performance. Another study found that ketone dieters reduced 50-minute time trial performance in cyclists, though another group of researchers have criticized the methods. Even when a ketone ester didn’t improve performance in the shuttle run to exhaustion and 15 meter sprint repeats, it did reduce the drop in brain function following the exercise.

Exogenous ketones provide the body with another fuel to employ. Think about it like an electric car that runs on both gas and electricity: by consuming ketones along with carbohydrates, the body will preferentially burn the ketones first, saving the carbohydrates for later. Exogenous ketones allow us to enter a metabolic state that wouldn't occur naturally: the state of having full carbohydrate stores, as well as elevated ketones in the blood. This could be advantageous to athletes looking to boost their physical performance. 
Ketones naturally exist in the body, being created during the process of fat metabolism and are therefore safe to consume even during pregnancy or breastfeeding. Supplements such as Ketologie’s PROBHB are simply providing ketones from an external (exogenous means literally ‘outside of the body’) source. However, if you suffer from any medical conditions and/or are on medications, it is always advisable to consult your health care provider prior to starting any new nutritional or dietary supplement.  

Ketogenic diets have been successfully used to treat diseases that have an underlying metabolic component, effectively decreasing seizures in recalcitrant pediatric epilepsy (Kossoff et al., 2003), lowering blood glucose concentrations in type 2 diabetes mellitus (Feinman et al., 2015) and aiding weight-loss (Bueno et al., 2013). Emerging evidence supports several clinical uses of ketogenic diets, for example in neurodegenerative diseases (Vanitallie et al., 2005), specific genetic disorders of metabolism (Veech, 2004) and as an adjunct to cancer therapy (Nebeling et al., 1995). Ketone bodies themselves may underlie the efficacy of the ketogenic diet, either through their role as a respiratory fuel, by altering the use of carbohydrate, protein and lipids (Thompson and Wu, 1991; Cox et al., 2016), or through other extra- and intracellular signaling effects (Newman and Verdin, 2014). Furthermore, ketone metabolism may offer a strategy to improve endurance performance and recovery from exercise (Cox et al., 2016; Evans et al., 2017; Holdsworth et al., 2017; Vandoorne et al., 2017). However, achieving compliance to a ketogenic diet can be difficult for both patients and athletes and may have undesirable side effects, such as gastro-intestinal upset (Cai et al., 2017), dyslipidemia (Kwiterovich et al., 2003) or decreased exercise “efficiency” (Edwards et al., 2011; Burke et al., 2016). Hence, alternative methods to raise blood ketone concentrations have been sought to provide the benefits of a ketogenic diet with no other dietary changes.

Weight loss benefits ushered the keto diet into the spotlight. That’s how most people have likely heard about ketones, a fuel source created naturally by the body when burning fat. But more and more research points to diverse applications of ketones in the blood outside of just fat loss, from improved endurance performance to the treatment of medical conditions like epilepsy.
The liver is always producing ketones to some small degree and they are always present in the bloodstream. Under normal dietary conditions, ketone concentrations are simply too low to be of any significant benefit. A ketogenic diet and exogenous ketone supplements will increase the amount of ketone in your body. The idea that  ketones are “toxic” is ridiculous. Ketones are a normal physiological substance that play many important roles in the human body.

I heard a rep from Perfect Keto on a podcast and your Exogenous Ketones. I ordered and received it the other day. I see from this article that I should not do a full scoop at once, but break it up in a day. Good to know. I had about a half scoop before I worked out this morning and could tell I had more energy. Loved that. Just curious….any ideas how long it will take me to get back into ketosis and fat burning?? (I know it depends on what I eat, but a general idea that I promise not to hold you too! (I’m actually missing having ‘keto breath!)
The ‘carb-sparing’ effect from BHB suppresses the break down of muscle glycogen. This leads to lower lactate levels. When increasing exercise intensity, fat oxidation (burning) reaches a limit. At that point the muscle burns carbohydrates as fuel. But when consuming Ketone esters, the body does not make this switch. This suggests Ketones are being used instead. 11
Effects of ketone supplementation on blood βHB. a, b Blood βHB levels at times 0, 0.5, 1, 4, 8, and 12 h post intragastric gavage for ketone supplements tested. a BMS + MCT and MCT supplementation rapidly elevated and sustained significant βHB elevation compared to controls for the duration of the 4-week dose escalation study. BMS did not significantly elevate βHB at any time point tested compared to controls. b BD and KE supplements, maintained at 5 g/kg, significantly elevated βHB levels for the duration of the 4-week study. Two-Way ANOVA with Tukey’s post hoc test, results considered significant if p < 0.05. Error bars represent mean (SD)
Background and aims: Currently there is considerable interest in ketone metabolism owing to recently reported benefits of ketosis for human health. Traditionally, ketosis has been achieved by following a high-fat, low-carbohydrate “ketogenic” diet, but adherence to such diets can be difficult. An alternative way to increase blood D-β-hydroxybutyrate (D-βHB) concentrations is ketone drinks, but the metabolic effects of exogenous ketones are relatively unknown. Here, healthy human volunteers took part in three randomized metabolic studies of drinks containing a ketone ester (KE); (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, or ketone salts (KS); sodium plus potassium βHB.
One common concern regarding the KD is its purported potential to increase the risk of atherosclerosis by elevating blood cholesterol and triglyceride levels [55, 56]. This topic remains controversial as some, but not all, studies have demonstrated that the KD elevates blood levels of cholesterol and triglycerides [57–62]. Kwitervich and colleagues demonstrated an increase in low-density lipoprotein (LDL) and a decrease in high-density lipoprotein (HDL) in epileptic children fed the classical KD for two years [27]. In this study, total cholesterol increased by ~130 %, and stabilized at the elevated level over the 2-year period. A similar study demonstrated that the lipid profile returned to baseline in children who remained on the KD for six years [63]. Children typically remain on the diet for approximately two years then return to a diet of common fat and carbohydrate ingestion [64]. The implications of these findings are unclear, since the influence of cholesterol on cardiovascular health is controversial and macronutrient sources of the diet vary per study. In contrast to these studies, the majority of recent studies have suggested that the KD can actually lead to significant benefits in biomarkers of metabolic health, including blood lipid profiles [65–72]. In these studies, the KD positively altered blood lipids, decreasing total triglycerides and cholesterol while increasing the ratio of HDL to LDL [68–77]. Although, the KD is well-established in children, it has only recently been utilized as a strategy to control seizures in adults. In 2014, Schoeler and colleagues reported on the feasibility of the KD for adults, concluding that 39 % of individuals achieved > 50 % reduction in seizure frequency, similar to the results reported in pediatric studies. Patients experienced similar gastrointestinal adverse advents that have been previously described in pediatric patients, but they did not lead to discontinuation of the diet in any patient [78].
However, with the ketone esters, the effects are nearly immediate, and my entire body was humming throughout the entire day, but not in a jittery way. I was full of mental and physical energy that lasted without any sort of crash (it was a gradual taper). During my cognitive tests, things felt almost effortless as I played the various games. After my experiment was complete I continued writing code for several hours, then went to the gym to work out. I did forget to each lunch though, so there must be some suppressive effect on appetite.
I started this website because it was hard to find trustworthy, evidence-based information about the ketogenic diet. Information that was published and peer reviewed by respected scientific journals. After years of research, I'm sure you'll achieve great results in a healthy way following my advice. I do my best to translate scientific research jargon into plain English. Remember, it's always a good idea to consult a doctor before starting a new diet!

Sometimes waiting for your body to make the switch from carbohydrate metabolism to beta hydroxybutyrate metabolism (aka ketosis) can be an uncomfortable and lengthy process. Another way to get beta hydroxybutyrate into your system so your body is using “clean” energy is by taking it supplementally or through nutrition. A betahydroxybutyrate supplement is what can be used in this scenario. This is an exogenous ketone. Exogenous means you get it from outside of your body. Think EX = exit = outside.

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Medical Disclaimer: The material on this site is provided for informational purposes only and is not medical advice. Always consult your physician before beginning any diet or exercise program.

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