Caveat emptor: the following post doesn’t come close to answering most of these questions. I only document my experience with BHB salts (and a non-commercial version at that), but say little to nothing about my experience with BHB esters or AcAc esters. But it will provide you will some context and understanding about what exogenous ketones are, and what they might do for athletic performance. We’ll likely podcast about the questions and topics above and cover other aspects of exogenous ketones in more detail.
For all studies, the area under the curve (AUC) of blood [βHB] was calculated using the trapezium rule. In Study 3, for each of the three drinks, the initial rate of d-βHB appearance was estimated using d-βHB concentrations at baseline and 30 min post-drink, and d-βHB elimination was estimated using the AUC between the post-drink peak (60 min) and trough (180 min) d-βHB concentrations, with a baseline correction to the value at 180 min.
Hi Mark, sorry this is off topic but not sure where to send a question for a future Ask Mark. I’m about to go into my yearly physical and I am wondering if there is any specific bloodwork that you like to do for your annual check up. I’m 47 year’s old and the than the basic blood work like lipid panel, etc..I’m going to ask my doctor to test my testosterone, HbA1C, fasting insulin, and Vitamin D levels. I’m also going to ask my doctor to do a stool test to check for parasites or other infections I may have picked up from open water swimming for triathlons. Can you recommend any other blood work that might be useful? Thanks!

I have Type 2 Diabetes. I have bought a product that has Beta Hydroxybutyrate in it. Is it dangerous for me to take it whereas I am a Type 2 diabetic. Can it cause me to go into Diabetic ketoacidosis which is very dangerous for a diabetic even deadly. I have been trying to find an answer to my question and your sight seems to have the best insight on Beta Hydroxybutyrate . I bought the product without knowing it had Beta Hydroxybutyrate in it and have not tried it out of fear that it will cause me to go into Diabetic ketoacidosis. Other people I know have taken it and lost weight and I really want to take it but I am afraid. Just so you know it is on a patch with other elements in it. Please help me I look forward to your answer
In conclusion, drinks containing exogenous ketones, in either ester or salt form, can raise concentrations of blood βHB in humans, although elevation of l-βHB lasts longer after racemic KS consumption. Both KE and KS drinks mildly altered acid-base balance. Exogenous ketones lowered blood glucose and lipids without inhibiting endogenous insulin secretion. The KE delivered highly repeatable blood concentrations of d-βHB, although ketosis was decreased by a meal. Uptake and elimination of d-βHB were similar when several drinks were consumed in succession. The dietary KE could maintain ketosis using drinks taken regularly around a normal meal pattern, or using a continuous infusion via a nasogastric tube. Therefore, ketone drinks are a viable and practical alternative to dietary strategies to achieve ketosis.
Given that blood βHB after identical ketone drinks can be affected by factors such as food or exercise (Cox et al., 2016), the accuracy of tools for non-invasive monitoring of ketosis should be investigated. Breath acetone and urinary ketone measurements provide methods to approximate blood ketosis without repeated blood sampling (Martin and Wick, 1943; Taboulet et al., 2007). However, breath acetone did not change as rapidly as blood βHB following KE and KS drinks. Acetone is a fat-soluble molecule, so may have been sequestered into lipids before being slowly released, resulting in the differences observed here. Similarly, significant differences in blood d-βHB between study conditions were not reflected in the urinary d-βHB elimination. As the amount of d-βHB excreted in the urine (≈0.1–0.5 g) represented ~1.5% of the total consumed (≈23.7 g), it appears that the major fate of exogenous d-βHB was oxidation in peripheral tissues. These results suggest that neither breath acetone nor urinary ketone measurements accurately reflect the rapid changes in blood ketone concentrations after ketone drinks, and that blood measurement should be the preferred method to quantitatively describe ketosis. That said, it should be noted that although commercial handheld monitors are the most practical and widely available tool for measuring blood ketones, they can overestimate blood D-βHB compared to laboratory measures (Guimont et al., 2015) and these monitors do not measure L-βHB and so may not provide accurate total blood ketone concentrations, especially if a racemic ketone salt has been consumed.
I’m already following a ketogenic diet and have been fat adapted for about 3 months. Since I’m already in ketosis would this product help me or hinder my fat loss? My thought is that if I’m already in a fat burning state and then I take exogenous ketones does my body stop burning my fat to burn the ingested ketones like taking a break or does the product enhance the fat burning that is already taking place?
Ketone supplementation did not affect the size of the brain, lungs, kidneys or heart of rats. As previously mentioned, the rats were still growing during the experimental time frame; therefore, organ weights were normalized to body weight to determine if organ weight changed independently to growth. There could be several reasons why ketones influenced liver and spleen weight. The ratio of liver to body weight was significantly higher in the MCT supplemented animals (Fig. 5). MCTs are readily absorbed in the intestinal lumen and transported directly to the liver via hepatic portal circulation. When given a large bolus, such as in this study, the amount of MCTs in the liver will likely exceed the β-oxidation rate, causing the MCTs to be deposited in the liver as fat droplets [94]. The accumulated MCT droplets in the liver could explain the higher liver weight to body weight percentage observed with MCT supplemented rats. Future toxicology and histological studies will be needed to determine the cause of the observed hepatomegaly. It should be emphasized that the dose in this study is not optimized in humans. We speculate that an optimized human dose would be lower and may not cause hepatomegaly or potential fat accumulation. Nutritional ketosis achieved with the KD has been shown to decrease inflammatory markers such as TNF-α, IL-6, IL-8, MCP-1, E-selectin, I-CAM, and PAI-1 [8, 46], which may account for the observed decrease in spleen weight. As previously mentioned, Veech and colleagues demonstrated that exogenous supplementation of 5 mM βHB resulted in a 28 % increase in hydraulic work in the working perfused rat heart and a significant decrease in oxygen consumption [28, 41, 42]. Ketone bodies have been shown to increase cerebral blood flow and perfusion [95]. Also, ketone bodies have been shown to increase ATP synthesis and enhance the efficiency of ATP production [14, 28, 40]. It is possible that sustained ketosis results in enhanced cardiac efficiency and O2 consumption. Even though the size of the heart did not change for any of the ketone supplements, further analysis of tissues harvested from the ketone-supplemented rats will be needed to determine any morphological changes and to understand changes in organ size. It should be noted that the Harlan standard rodent chow 2018 is nutritionally complete and formulated with high-quality ingredients to optimize gestation, lactation, growth, and overall health of the animals. The same cannot be said for the standard American diet (SAD). Therefore, we plan to investigate the effects of ketone supplements administered with the SAD to determine if similar effects will be seen when the micronutrient deficiencies and macronutrient profile mimics what most Americans consume.
For all studies, the area under the curve (AUC) of blood [βHB] was calculated using the trapezium rule. In Study 3, for each of the three drinks, the initial rate of d-βHB appearance was estimated using d-βHB concentrations at baseline and 30 min post-drink, and d-βHB elimination was estimated using the AUC between the post-drink peak (60 min) and trough (180 min) d-βHB concentrations, with a baseline correction to the value at 180 min.
If you've tried this type of diet before, or if you've done some research about it beforehand, then you should know that these ten tricks are necessary to get into a ketogenic state quickly, but you will be surprised at the number of people who actually jump on the ketogenic bandwagon without knowing any of the basics first. Remember: A good working knowledge coupled with an effective meal plan can go a long way.
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.
“Imagining that everyone is going to go on a ketogenic diet is very unlikely. I’ve done it myself, and it is hard as a diet to sustain for a long period of time,” said Verdin. “The interest for us in BHB is [if] can we recapitulate all the beneficial effects that we are seeing from the ketogenic diet simply by administering BHB as a food or as a drug, whatever you want to call it.”

A lot of people who use ketogenic diets will include a regular (i.e. weekly) carb refeed meal. There are various reasons behind doing this. If you are doing a lot of glycolic based training, then the carb refeed can help bump up muscle glycogen levels and in turn boost performance. Others use these refeeds as a way to keep their thyroid health in check, and finally some people use these refeeds as a ‘cheat day’ – so that they can still enjoy the pleasures from carbohydrates!

KE was synthesized as previously described [29]. BMS is a novel agent (sodium/potassium- βHB mineral salt) supplied as a 50 % solution containing approximately 375 mg/g of pure βHB and 125 mg/g of sodium/potassium. Both KE and BMS were developed and synthesized in collaboration with Savind Inc. Pharmaceutical grade MCT oil (~65 % caprylic triglyceride; 45 % capric triglyceride) was purchased from Now Foods (Bloomingdale, IL). BMS was formulated in a 1:1 ratio with MCT at the University of South Florida (USF), yielding a final mixture of 25 % water, 25 % pure βHB mineral salt and 50 % MCT. BD was purchased from Sigma-Aldrich (Prod # B84785, Milwaukee, WI).


Blood glucose concentrations are decreased during both exogenous and endogenous ketosis, although by different mechanisms. During endogenous ketosis, dietary carbohydrate deficit is the underlying cause of low blood glucose, along with reduced hepatic gluconeogenesis and increased ketone production (Cahill et al., 1966). With exogenous ketosis, carbohydrate stores are plentiful, yet ketones appear to lower blood glucose through limiting hepatic gluconeogenesis and increasing peripheral glucose uptake (Mikkelsen et al., 2015). One clinical use of the ketogenic diet is to improve blood glucose control, yet the elevated blood FFA may increase the risk of heart failure (Holloway et al., 2009). Thus, the ability of exogenous ketones to lower blood glucose without elevating blood FFA concentrations could deliver the desired effect of the diet, whilst also decreasing a potential risk.
Sure Leslie, the goal is to induce the burning of stored fat in your body. This process usually take a few days of strictly limiting carbohydrate intake. Supplementing with exogenous ketones is a way to shortcut the wait time, essentially “tricking” your body into ketosis. I imagine supplementing with too many could have negative effects on fat loss, but the research is not out supporting that claim yet.
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 mU.ml−1 after both the meal and the dextrose drink, but also increased to 13 ± 2 mU.ml−1 when KE was consumed whilst fasted owing to the 15 g of glucose in the flavored drink used as a diluent (Figure ​(Figure5D5D).
Plenty of supplements make you a fractionally better sportsman and these are no different. The synthetic exogenous ketones helped Olympic-caliber cyclists cover an average of 411 additional meters during a 30-minute time-trial, which resulted in a two percent increase in overall speed, found a paper in Cell Metabolism. That can be the difference between feeling the glorious tug of the winner’s ribbon across your chest or rolling in with the stragglers.
Improved cognition: Elevated plasma ketone concentrations divert the brain to utilize ketone bodies for synthesis of phospholipids, which drives growth and myelination. Normally, glucose would be the preferred substrate, which is much less efficient.14 BHB seems to act as a signal for neuronal pathways. These enhance synaptic plasticity, cognition and neuronal stress resistance. 15 In rat studies, ingestion of a ketone ester for 5 days improved their spatial learning and memory. 16.
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.

You may find a tiny amount here and there is ok (i.e., 2g of sugar with a meal full of fat may be ok).  But if you are starting out I would recommend cutting all sugar from your diet, and most importantly avoiding any sugar consumption on an empty stomach. For best results track your ketone levels before and after meals to see the impact the food has on your ketone levels.
I have, though, recently been diagnosed with ovarian cancer. After reading through your blog, I noticed there was a little about Ketogenetic diet and cancer. I purchased the MCT oil powder in hopes that will help me get into ketosis for the purpose of “starving” the cancer cells. Other then focus, I didn’t see any particular format for something like this. Here are my questions: How much of the powder should I take? And do you think the diet plus the MCT oil is a good idea for 1) aiding chemotherapy and 2) helping shrink the number of cancer cells?
For all studies, the area under the curve (AUC) of blood [βHB] was calculated using the trapezium rule. In Study 3, for each of the three drinks, the initial rate of d-βHB appearance was estimated using d-βHB concentrations at baseline and 30 min post-drink, and d-βHB elimination was estimated using the AUC between the post-drink peak (60 min) and trough (180 min) d-βHB concentrations, with a baseline correction to the value at 180 min.
The difference in peak blood d-βHB concentrations between matched amounts of βHB as ester or salts arose because the salt contained l-βHB, as the blood concentrations of d- plus l-βHB isoforms were similar for both compounds. It is unclear if kinetic parameters of KE and KS drinks would be similar if matched d-βHB were taken in the drinks. Unlike d-βHB, blood l-βHB remained elevated for at least 8 h following the drink, suggesting an overall lower rate of metabolism of l-βHB as urinary elimination of l-βHB was in proportion to plasma concentration. Despite similar concentrations of total βHB, breath acetone was ~50% lower following KS drinks compared to KE, suggesting fundamental differences in the metabolic fates of D- and L-βHB. These findings support both previous hypotheses (Veech and King, 2016) and experimental work in rats (Webber and Edmond, 1977), which suggested that the l-isoform was less readily oxidized than the d-isoform, and is processed via different pathways, perhaps in different cellular compartments. It seems that l-βHB is not a major oxidative fuel at rest, and may accumulate with repeated KS drinks. However, the putative signaling role of l-βHB in humans remains unclear. In rodent cardiomyocytes, l-βHB acts as a signal that modulates the metabolism of d-βHB and glucose, Tsai et al. (2006) although no differences in blood glucose were seen here. Furthermore, L-βHB can act as a cellular antioxidant, although to a lesser extent than D-βHB (Haces et al., 2008).
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 shred weight in their sleep. Seriously... how is that even scientifically possible. So if you are thinking about trying out a particular supplement, I would suggest two things:

Importantly, at Diet Doctor we do not think you need to spend any extra money at all in order to revolutionize your health. You can achieve radiant health just by enjoying authentic food that is naturally low in carbohydrates, getting plenty of sleep and some exercise (going for a walk is free) and reducing stress. A lot of you who answered the survey made exactly these points in your explanations of reasons for not taking the supplements. I whole-heartedly agree.
Beta hydroxybutyrate floats around in your blood, and importantly, can cross different barriers to be able to be turned into energy at all times. One of the most important areas where this happens is in the brain. The blood-brain barrier (BBB) is usually a very tightly regulated interface that doesn’t allow the transfer of many molecules, but since BHB is such a rock star and so hydrophilic, your brain knows to let it in so it can bring energy to the party at any time. This is one of the main reasons why increased levels of ketosis lead to improved mental clarity, focus and reduction in neurodegenerative diseases.
There is one viable explanation for consuming ketones. If you're in a calorie or carb-restricted state, then maybe during a workout it would make sense. But even then, that really only applies to endurance activities, since it has more to do with enhancing aerobic performance (where oxygen is required), than it does with enhancing high-intensity efforts (where it's not).
When your body transitions from using energy from carbohydrates to ketones, there can be a lot of nasty and unwanted side effects. These include low energy, bloating, irritability, headaches and fatigue. This is because your body is “in between” burning carbs and burning ketones and hasn’t become efficient at burning ketones and producing them from your fat stores yet.
I'm using this in conjunction with a low carb diet (40g net daily) and Adipex. Perfect Keto actually helped alleviate a lot of the keto/low carb flu symptoms I typically experience when starting a low carb diet. I can't give a full review on how this works with weight loss, because I'm just using it as a supplement (1 scoop) to help keep me in solid ketosis and have only been doing so for the past two weeks and using the low carb diet and Adipex in addition to this supplement doesn't give me a pure experience with this product. But I'm down 10 pounds in the two weeks, so I'm sure it's playing a part!

Most people know that you can lose weight by consuming fewer carbs and a lot more protein. However, it's very important that you watch your protein intake carefully if you want to achieve ketosis quickly. There needs to be a balance in the amount of protein you are consuming, since too much of it is not going to be beneficial for you. What you need to remember is that this process is all about getting the right balance of fats, proteins, magnesium, salts, etc., to get your body into ketosis faster.

With single doses of the D-BHB ester as a sports drink, gastrointestinal (GI) side effects are rare. Some studies have reported mild GI side-effects of HVMN Ketone drinks at extremely high doses (4x serving size) or when given in a thick, meal replacement formulation.10,13 However, other studies of athletes reported there were no side-effects of ketone ester drinks hindering sport performance.11,14
It's important to listen to your body when going through the ketogenic process. This means that you should only eat when you're hungry and not every single time you get a craving. It's our obsession with food that causes us to stuff ourselves whenever we feel like it, and you should know by now that it's not healthy to do that. When you make it a point to eat only when you're hungry, you're diminishing any food intake that your body doesn't really need. 
The fate of excess ketones: In the event someone has an excessive amount of ketones in the blood, the body (specifically the kidneys) will work as quickly as possible to filter out ketones via urine rather than converting them to adipose tissue.9 This is not to say that you can’t gain fat if you consume an exorbitant amount of exogenous ketones, but that they are less prone to be converted to fat than other nutrients.
Too much cortisol tells the liver that you are in physical danger and need a lot of energy fast. The brain doesn’t understand the difference between physical danger and emotional stress. When emotionally stressed, the brain thinks you’re in a life-and-death situation, so the liver comes to your rescue and gives you the glucose you need to fight off your attacker.
For example, the popular Raspberry Ketones supplement is far different than what we have been discussing in this article. Raspberry ketones are unrelated to the ketones that are produced in the body and are not the same as the ketone salts that have been covered above. There are some limited studies that indicate raspberry ketones may be helpful for weight loss, but they are inconsistent. Raspberry ketones are the molecules that give raspberries their scent and flavor, and in some cases, aren’t even derived from raspberries at all.
As I mentioned before, this was by no means a scientific experiment carried out under lab conditions, and this means we can only draw tentative conclusions from any of the data. Nonetheless, carrying out the testing in the way described above should give most people a good idea of how well the ketone supplements show the noticeable benefits they are marketed to have and provide a clear enough basis for a decision on whether or not to buy them.
While the KetoneAid folks have been seeing tremendous success working with elite athletes to improve athletic performance, I thought it would be interesting to quantify the effects of ketone esters on cognitive performance. For the week prior to taking the ketones, I re-established baseline scores in a number of cognitive testing areas using Lumosity*:
Personally, I do this on Friday night to Saturday night, so if something happens and my hunger hasn’t crashed by Sunday morning, I have another day that I can go zero carb to keep the momentum going. While the body will trigger ketosis as soon as you run out of glycogen, hunger is attached to your triglyceride and insulin levels, which might take an extra day to normalize.
Working memory involves temporarily storing and manipulating information. The game involves seeing three cards – a top card with a symbol that then moves along a track and is flipped over, exposing a new card above. The goal is to remember the symbol of the cards two cards back and indicate whether it matches the visible card or not. If you have ever played dual n-back games, this is very similar.

Exercising is undoubtedly important when it comes to losing weight. An added bonus of being in a state of ketosis is the ability to improve your exercise performance, but you should also remember that entering ketosis for the first time can be a bit of a challenge for a lot of people. The body is still adjusting to such a dramatic diet change, so exercising may prove to be difficult at first. The key here is to keep going.


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).
Appetite suppression: Appetite was measured in 10 males and 5 females after consuming a ketone ester (KE) or a dextrose (DEXT) drink . Desire to eat and perception of hunger dropped after both drinks, but the KE was 50% more effective for 1.5-4hrs. Insulin levels rose for both drinks but were 3x less with the KE drink after 30mins (Fig 2). The hunger hormone, ghrelin, was significantly lower between 2 to 4 hours after drinking the KE (Fig 2). In conclusion Ketone esters delay the onset of hunger and lower the desire to eat. 8

Exogenously delivered ketone supplements significantly altered rat weight gain for the duration of the study (Fig. 6). However, rats did not lose weight and maintained a healthy range for their age. Rats have been shown to effectively balance their caloric intake to prevent weight loss/gain [97–99]. Due to the caloric density of the exogenous ketone supplements (Table 1) it is possible for the rats to eat less of the standard rodent chow and therefore less carbohydrates while maintaining their caloric intake. Food intake was not measured for this study. However, if there was a significant carbohydrate restriction there would be a signifcant change in basal blood ketone and blood glucose levels. As the hallmark to the KD, carbohydrate restriction increases blood ketone levels and reduces blood glucose levels. Neither an increase in basal blood ketone levels nor a decrease in basal blood glucose levels was observed in this study (Fig. 7). Additionally, if there were an overall blood glucose decrease due to a change in food intake, this would not explain the rapid reduction (within 30 min) in blood glucose correlated with an elevation of blood ketone levels after an intragastric bolus of ketone supplement (Figs. 2, ​,33 and ​and44).
If the goal is to deplete glucose levels so that we can start producing ketone bodies, then forcibly exerting physical energy through exercise is a great way to go about it. Keeping it relatively low intensity to begin with and working out in the morning is recommended as this helps to keep down your cortisol (stress hormone) levels. This only applies at the beginning of your keto adaptation process, as intense workouts such as HIIT once already keto-adapted will be completely fine.

In the second of these posts I discuss the Delta G implications of the body using ketones (specifically, beta-hydroxybutyrate, or BHB, and acetoacetate, or AcAc) for ATP generation, instead of glucose and free fatty acid (FFA). At the time I wrote that post I was particularly (read: personally) interested in the Delta G arbitrage. Stated simply, per unit of carbon, utilization of BHB offers more ATP for the same amount of oxygen consumption (as corollary, generation of the same amount of ATP requires less oxygen consumption, when compared to glucose or FFA).

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