At the same time, research suggests that getting as much of your calcium from your diet, rather than supplements is a good idea. For instance, there is some evidence that the calcium intake from food is better for bone mineral density than the same calcium intake from supplements[17]. Foods that are high in calcium include dairy, leafy green vegetables, fish with edible bones, tofu made with calcium sulfate, and calcium-fortified foods and beverages.
Effects of ketone supplementation on blood glucose. a, b Blood glucose levels at times 0, 0.5, 1, 4, 8, and 12 h (for 10 dose) post intragastric gavage for ketone supplements tested. a Ketone supplements BMS + MCT and MCT significantly reduced blood glucose levels compared to controls for the duration of the 4-week study. BMS significantly lowered blood glucose only at 8 h/week 1 and 12 h/week 3 (b) KE, maintained at 5 g/kg, significantly reduced blood glucose compared to controls from week 1–4. BD did not significantly affect blood glucose levels at any time point during 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)
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.
Meanwhile Brinkworth, et al., in their 2009 paper "Long-term Effects of a Very Low-Carbohydrate Diet and a Low-Fat Diet on Mood and Cognitive Function" looked at the effects on ketogenic diet on cognitive function and mood. The study participants ate a ketogenic diet for a year and the researchers found that mood levels decreased when compared to a group eating a high carb/low fat diet. They go on to remark “there was no evidence that the dietary macronutrient composition of LC and LF diets affected cognitive functioning over the long term, as changes in cognitive function were similar for both diets”.
Considering both the broad therapeutic potential and limitations of the KD, an oral exogenous ketone supplement capable of inducing sustained therapeutic ketosis without the need for dietary restriction would serve as a practical alternative. Several natural and synthetic ketone supplements capable of inducing nutritional ketosis have been identified. Desrochers et al. elevated ketone bodies in the blood of pigs (>0.5 mM) using exogenous ketone supplements: (R, S)-1,3 butanediol and (R, S)-1,3 butanediol-acetoacetate monoesters and diester [48]. In 2012, Clarke et al. demonstrated the safety and efficacy of chronic oral administration of a ketone monoester of R-βHB in rats and humans [49, 50]. Subjects maintained elevated blood ketones without dietary restriction and experienced little to no adverse side effects, demonstrating the potential to circumvent the restrictive diet typically needed to achieve therapeutic ketosis. We hypothesized that exogenous ketone supplements could produce sustained hyperketonemia (>0.5 mM) without dietary restriction and without negatively influencing metabolic biomarkers, such as blood glucose, total cholesterol, HDL, LDL, and triglycerides. Thus, we measured these biomarkers during a 28-day administration of the following ketone supplements in rats: naturally-derived ketogenic supplements included medium chain triglyceride oil (MCT), sodium/potassium -βHB mineral salt (BMS), and sodium/potassium -βHB mineral salt + medium chain triglyceride oil 1:1 mixture (BMS + MCT) and synthetically produced ketogenic supplements included 1, 3-butanediol (BD), 1, 3-butanediol acetoacetate diester/ ketone ester (KE).

If you have already mastered the Very Low Carbohydrate (VLC) or ketogenic way of eating, and/or are eating at a caloric deficit, exercising or fasting you are naturally creating the optimal conditions for your body to produce ketones and put your body into nutritional ketosis. By strict adherence to a well-formulated ketogenic diet (complete with higher levels of mineral salts) you should be able to produce all the ketones you need naturally (endogenously). If you are new or inexperienced in ketogenic eating however; or if you or a family member struggles to adhere to a ketogenic diet, then supplementation with exogenous ketones may be very beneficial. Not only will ketone supplements help to mitigate hunger and carb cravings, but they will also help you stave off carb flu symptoms (see below), giving you the best possible chance of long-term success.
After a minimal amount of internet "research," I decided to try my first exogenous ketones. I have used the ketogenic diet off and on for at 15 years and my body is pretty efficient at fat adapting. (Usually by the end of 2 strict days, I am in ketosis, but not without symptoms and intense cravings.) I can consistently fast from carbs for 20 - 24 hours and do this consistently. However, around hour 20, my mind begins to negotiate that intermittent fasting is advantageous too and that I can afford to have some carbs once a day. Hence the yo-yo effect.
How to get into ketosis in 24 hours you ask? Can it be done? Yes, it can happen. But only for people who have already been keto-adapted and may have dropped out of ketosis for a short period of time, like after a cheat day. Those people can follow these steps to get back into ketosis quickly. However, if you are just starting keto you have a lot of work to do before your body will let you get into ketosis.
Ketones may be a better source of fuel than glucose, and a far better beverage than Fruitopia, but it's a question of whether or not you can spare the extra fuel. Because just like adding sugar to a diet, it's like pressing pause on the fat burning process since the body preferentially burns it for fuel. Adding ketones to the diet does the same thing.
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.

The Zenwise Keto Life BHB Salt uses a custom calcium, magnesium and sodium ketone complex to help access ketones for fuel without the low carb diet or fasting. This product is another all-natural option that goes as far as using turmeric for its added coloring. It is a proven product with hundreds of happy customers. They seem to have a strong grasp on the lemonade side of the exogenous market with their Raspberry Lemonade and Wild Limeade flavor choices.
There is a great deal of positive speculation that exogenous ketones can be beneficial for inflammation, cognitive enhancement, and even protection against certain types of cancer. There is mounting evidence that the ketogenic way of eating can help many people, and when used appropriately with realistic expectations, exogenous ketone supplementation can enhance these positive effects (25).
The many roles of magnesium include helping us maintain normal nerve and muscle function, as well as heart rate, supporting a healthy immune system, regulating blood glucose levels, and making energy production and protein synthesis possible[23]. Magnesium is also involved in both aerobic and anaerobic energy production. ATP synthesis (the body’s energy source) depends on enzymes that are activated by magnesium.

The problem? Exogenous ketone supplements work by flooding your bloodstream with ketones. But unless you’re also eating a ketogenic diet (and producing a steady stream of ketones naturally), those supplemental ketones won’t stick around forever. “The benefit of exogenous ketones is limited due to their excretion through the urine,” explains Madge Barnes, MD, family medicine specialist with Texas Health Family Care. In other words? They’ll only work for a few hours until you pee them out. As a result, you need to keep on supplementing—which can get expensive. Twenty single-serving packets of Prüvit’s Keto//OS MAX Pure Therapeutic Ketones, for example, cost $130. (The company doesn’t specify how often you should take them.)
Even though there is mixed evidence regarding the association between calcium supplementation and cardiovascular events, there may be other reasons to avoid high calcium supplementation. In one of his studies, Dr. Bolland claimed that calcium supplements do not prevent hip fractures. Rather, they may lead to kidney stones, acute gastrointestinal events, and increased risk of myocardial infarction and stroke. Thus, the risks involved with high-calcium supplementation potentially outweigh the benefits[21].
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?
If you read about ketosis in magazine or heard about it in a podcast and wanted to jump on the bandwagon, then I think you should avoid it. Remember, it is a strict diet, and the potential health downsides may not be worth the upsides, unless you are working with a medical professional and or you are tracking your labs to see what’s going on with your health (thyroid).
I don’t think we even need a drumroll here… Based on my background research into ketone-supplement companies, the survey of Diet Doctor users and the experiment itself, we cannot recommend taking these supplements. I can personally think of many more beneficial ways to invest money in my health, such as buying grass-fed meat and organic vegetables, or even buying a bicycle and riding it outside in the sunshine.
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].
KE consumption decreased FFA from 0.6 to 0.2 mM, TG from 1.0 to 0.8 mM, and glucose from 5.5 to 4.7 mM by the end of the study (4 h). The effect was not altered by a meal (Figures 5A–C). Dextrose drinks also lowered FFA from 0.6 to 0.2 mM and TG from 1.0 to 0.7 mM (Figures 5A, B). This was likely mediated by the transient increase in glucose, which rose from 4.6 to 6.5 mM following the dextrose drink (Figure ​(Figure5C).5C). The anti-lypoytic effect of dextrose drinks was shorter than that of KE drinks as d-βHB concentrations were elevated for longer after KE drinks than glucose after dextrose drinks. Insulin increased to ~ 35−1 after both the meal and the dextrose drink, but also increased to 13 ± 2−1 when KE was consumed whilst fasted owing to the 15 g of glucose in the flavored drink used as a diluent (Figure ​(Figure5D5D).
Ketostix are very unreliable. There are many factors which can alter results such as hydration level, if you’ve worked out recently and the amount of unused ketones in your body to name just a few. Never rely of Ketostix to determine whether you are in ketosis or not. The Precision Xtra blood ketone monitor is the gold standard for testing for ketones in your body. After following a ketogenic diet for a while, you should be able to tell if you are in ketosis or not by the way you feel.
The way you make an exogenous BHB is by attaching it to some type of other compound (sodium, potassium, calcium, or magnesium) so that your body can process the molecule by cleaving the bond between the salt and the beta hydroxybutyrate. BHB + bound to a salt = BHB salts, which is what most people in the ketosis community call exogenous ketones. There are also things called esters, which are basically unbound BHB molecules. These are really disgusting and cause massive digestive issues, so I like to ignore them until we can produce them in a more appealing way.
One monk, for example, set out to do a 40 day fast with medical supervision while maintaining his daily activities in the monastery. After 36 days, the medical professionals had to step in due to “profound weakness” and low blood pressure when standing. Although the monk fasted for 15 days longer than Ghandi, the medical professionals were able to stop the fast in time so that he could recover.
Although decreases in FFA, TG and glucose occurred, there were no significant differences between the KE and KS drinks or with intake amount. Ingestion of ketone drinks significantly decreased overall mean plasma FFA from 0.7 to 0.4 mM, TG from 1.1 to 0.9 mM and glucose from 5.7 to 4.8 mM after 1 h (all p < 0.05). Concentrations were the same as at baseline by 4 h, with FFA at 0.6 mM, TG at 0.9 mM and glucose 5.1 mM (Figures 2A–C). There was a rise in insulin concentrations 30 min following all drinks, probably due to the small amount of carbohydrate in the sweetener (Figure ​(Figure2D2D).
Long-Term Effects of a Ketogenic Diet in Obese Patients – The present study shows the beneficial effects of a long-term ketogenic diet. It significantly reduced the body weight and body mass index of the patients. Furthermore, it decreased the level of triglycerides, LDL cholesterol and blood glucose, and increased the level of HDL cholesterol. Administering a ketogenic diet for a relatively longer period of time did not produce any significant side effects in the patients. Therefore, the present study confirms that it is safe to use a ketogenic diet for a longer period of time than previously demonstrated.
Exogenous ketones are created in a lab to accelerate both physical and mental performance. These ketone drinks were actually used in pro cycling races back in 2015, trading at prices that would make using your kidney as a bartering tool seem like a cut price deal. Fortunately, they’ve now come down in cost and are used often in between meals as a way of blackmailing your body into getting into ketosis way faster.

Hello! I’m planning on taking a short vacation and will be having “kept friendly” drinks, mostly vodka and water with lemon and stevia. When should I take my exogenous ketones? That night before bed or early the next morning or after the 3 day vacation is completely over? I’m unsure how to manage this to have the best odds of staying in ketosis and get back to burning FAT. Also, I just purchased Instaketones from Julian Bakery, what are your thoughts on this brand? Thanks for what you do!

Effects of ketone supplementation on basal blood ketone and basal blood glucose levels: Rats administered ketone supplements did not have a significant change in basal blood ketone levels (a) or basal blood glucose levels (b) for the four week study. Two-Way ANOVA with Tukey’s post-hoc test, results considered significant if p < 0.05. Error bars represent mean (SD)

To enter ketosis, up to 80%of your daily calories should come from fat. To put this into a frame of reference, if you eat 2,000 calories a day, 1,600 of those calories should come from fat sources. This comes out to roughly 144-170 grams of fat. Both quantity and quality are equally important, so consume fats from high-quality sources, like omega-3 and omega-6 fatty acids.

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!)
Even though there is mixed evidence regarding the association between calcium supplementation and cardiovascular events, there may be other reasons to avoid high calcium supplementation. In one of his studies, Dr. Bolland claimed that calcium supplements do not prevent hip fractures. Rather, they may lead to kidney stones, acute gastrointestinal events, and increased risk of myocardial infarction and stroke. Thus, the risks involved with high-calcium supplementation potentially outweigh the benefits[21].
Individuals who have clinically unregulated blood sugar, such as those with diabetes, are cautioned to consult their trusted healthcare provider before choosing to use exogenous ketones. While it can be done safely, especially in the presence of a well-formulated ketogenic food plan, there may be a risk of blood sugar dropping unexpectedly low. There may be therapeutic value in this application, but close monitoring is key.
Athletic performance benefits: The use of exogenous ketone supplements for bettering physical/athletic performance is promising for several reasons. Firstly, taking exogenous ketones (particularly BHB salts) induces acute nutritional ketosis for upwards of eight hours, mimicking fasting physiology (e.g. increases fat burning, insulin sensitivity, etc.).[3]
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:
Ketone Esters: These are not normally found in the body, but exogenous ketone esters convert into BHB once it is in the body. They are also synthetically (lab) made compounds that link an alcohol to a ketone body, which can then be metabolized by the liver into a ketone. They are like ketone salts on steroids as they have 5-10 time more BHB per serving/maximum daily intake than ketone salts. To date, pure ketone esters have been very expensive to produce and have only been available to researchers, elite athletes (Tour de France cyclists), and the US Department of Defense (people have spent more than $20,000 to have an independent lab produce a single serving!).
However, it's important to NEVER overlook the power of exercise and of course sticking to a proper routine to get the most optimized results. The most common mistake people make is by treating any keto supplement like a "wonder drug" that will help them shed weight in their sleep. Seriously... how is that even scientifically possible. So if you are thinking about trying out a particular keto supplement, I would suggest two things:
The second ketone ester compound was developed at the University of South Florida. This is a diester of AcAc and BDO. In rodents, this ketone ester raises blood D-BHB to 1-4 mM and blood AcAc to up to 5 mM.19 There is one published study of this ketone ester in humans; results showed a 2% decrease in 31 km cycling time trial performance.16 This may be due to the high rate of side effects of this ester studied. Other factors may have been low levels of BHB (<2 mM), the short, high-intensity time trial used, or the use of AcAc vs. BHB.
Keep these studies in mind as your body tries to play tricks on you during your first day of fasting.  Even after three days of fasting, health complications are highly unlikely. However, it is important to know about the possible issues that can be caused by fasting. If you choose to incorporate fasting into your daily diet, you typically want to eat every day as well. Occasionally going on a longer period of fasting.
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.
Over the 28-day experiment, ketone supplements administered daily significantly elevated blood ketone levels without dietary restriction (Fig. 2a, b). Naturally derived ketogenic supplements including MCT (5 g/kg) elicited a significant rapid elevation in blood βHB within 30–60 min that was sustained for 8 h. BMS + MCT (5 g/kg) elicited a significant elevation in blood βHB at 4 h, which was no longer significant at 8 h. BMS (5 g/kg) did not elicit a significant elevation in blood βHB at any time point. For days 14–28, BMS + MCT (10 g/kg) and MCT (10 g/kg) elevated blood βHB levels within 30 min and remained significantly elevated for up to 12 h. We observed a delay in the peak elevation of blood βHB: BMS + MCT peaked at 8 h instead of at 4 h and MCT at 4 h instead of at 1 h. Blood βHB levels in the BMS group did not show significant elevation at any time point, even after dose escalation (Fig. 2a). Synthetically derived ketogenic supplements including KE and BD supplementation rapidly elevated blood βHB within 30 min and was sustained for 8 h. For the rats receiving ketone supplementation in the form of BD or the KE, dosage was kept at 5 g/kg to prevent adverse effects associated with hyperketonemia. The Precision Xtra™ ketone monitoring system measures βHB only; therefore, total blood ketone levels (βHB + AcAc) would be higher than measured. For each of these groups, the blood βHB profile remained consistent following daily ketone supplementation administration over the 4-week duration. (Fig. 2b).
Interestingly, poly-BOHB has recently been reported to have important roles in mammalian mitochondrial membranes, cell membrane calcium channels, and in exotic functions like protein folding (Dedkova 2014). It exists in a variety of chain lengths, ranging from short to very long. It is not clear if humans can digest and use poly-BOHB consumed in the diet, but in animals, poly-BOHB appears to have probiotic and bowel protective functions. This is a rapidly evolving topic that we will be watching closely.
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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