Blood, breath, and urine ketone kinetics following mole-matched ketone ester (KE) and ketone salt (KS) drinks, at two amounts, in 15 subjects at rest. Values are means ± SEM. (A) Blood d-βHB. (B) Tmax of blood d-βHB. (C) AUC of blood d-βHB. (D) Isotopic abundance (%) of d- and l-chiral centers in pure liquid KE and KS. (E) Blood d-βHB and l-βHB concentrations in subjects (n = 5) consuming 3.2−1 of βHB in KS drinks. (F) d-βHB and l-βHB concentrations in urine samples from subjects (n = 10) consuming 3.2−1 of βHB in KS drinks. (G) Blood d- and l-βHB after 4, 8, and 24 h in subjects (n = 5) consuming 3.2−1 of βHB in KS drinks. (H) Breath acetone over 24 h in subjects (n = 5) consuming 3.2−1 of βHB in KE and KS drinks (ppm = parts per million). (I) Urine d-βHB excreted over 4 h after KE and KS drinks (n = 15). (J) Urine pH 4 h after drink, dotted line indicates baseline. †p < 0.05 KE vs. equivalent amount of KS, *p < 0.05 difference between 1.6 vs. 3.2−1 of βHB, §p < 0.05 difference between amounts of d- and l-βHB, p < 0.05 difference between baseline and post-drink level.

It comes in a small bottle that usually contains 50-100 strips depending on the type you choose. It’s very thin, and on one end there’s a small square of paper (this is the end you dip in the urine). If there are ketones in your urine, the little paper will change color. The darker it is (light pink up to a purple color) the more it is in your urine. On the bottle, there’s a picture you compare the color of the paper with that can be a very good indication of your current ketone state. 

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).
Intermittent fasting will significantly help the body transition into ketosis as limiting your consumption of food for that many hours will help deplete the system of any excess glucose. It’s a shock to the system and research has shown that daily fasting can have other profound effects aside from weight control such as autophagy, lowering risks of heart disease and diabetes, as well as an improvement in cognitive function. So if you’re still wondering how to get into ketosis in 24 hours, then fasting will surely kick things into gear!
One other thing I must point out is also that we are talking about being in ketosis and not being fully keto adapted. You enter ketosis when your body starts producing ketones above a specified level, being fully keto adapted means that your body is full adapted to  use fat as your primary energy source and that the production of certain enzymes in your body is fully adapted. This doesn’t happen in one day and it takes about 1 month on average to be fully keto adapted. But we are not looking for this as we just want to end the most unpleasant period and to start losing weight.

Medium-chain-triglycerides are fats that are easily absorbed by the body and provide a number of really powerful health benefits. Fast energy, appetite control for better weight loss, increased ketone levels—you name it. They are also one of the most convenient and flexible, too. Add it to a shake, make a smoothie, or take a spoonful of it straight with some water for a quick, healthy keto boost that lasts all day. If you’re the kind of person that struggles to stick to a diet or eat a lot throughout the day, MCT oils are the perfect keto supplement.
Participants refrained from alcohol and caffeine for 24 h prior to each visit AND were asked to consume a similar meal the night before each visit. All studies were carried out at the University of Oxford Human Physiology Laboratories and started at 0800 h following an overnight (>8 h) fast, with a minimum of 72 h between visits. Visit order was randomized prior to commencement by an administrative investigator using a pseudo-random number generator to produce a list of combinations of visit order, which were then allocated based on order of enrolment by a different investigator.
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.
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.

BHB Salts and exogenous ketone supplements are literally changing the supplement industry. These products are pretty new and a little more expensive than other supplements. But I’d rather pay for something that works then spend tons of money chasing products that claim to work. One of the most popular ketone supplements is Ketōnd. You can check out our review here.
Ketone monoester and diester compounds may circumvent the problems associated with inorganic ion consumption in KS drinks. KE ingestion rapidly increased blood ketone concentrations to >5 mM in animals (Desrochers et al., 1995a,b; Clarke et al., 2012a) and the first oral, non-racemic KE for human consumption, (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, raised blood βHB concentrations to 3–5 mM in healthy adults (Clarke et al., 2012b; Shivva et al., 2016) and athletes (Cox et al., 2016; Holdsworth et al., 2017; Vandoorne et al., 2017). However, the pharmacokinetics and pharmacodynamics of this KE with confounding factors, such as prandial state or multiple KE drinks, have not been characterized.
Ketogenic Diets and Physical Performance – Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15–25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis. (
Also known as the carb flu, the keto flu is commonly experienced by people who are transitioning to a Ketogenic diet. “Keto flu” is not actually flu but mimics the experience of flu with very similar symptoms. It can happen when someone who has become accustomed to relying primarily on carbohydrates as fuel removes them from their diet. Whilst this is a necessary step towards adjusting from being a sugar-burner to a fat-burner, the sudden change can trigger some unpleasant symptoms, much like withdrawing from an addictive substance. Keto flu symptoms can include drowsiness, nausea, dizziness, achy muscles, mental fogginess and an irritable mood. The good news though, is that most of these experiences relate to dehydration and electrolyte depletion, and so are easily prevented or managed. Simply adding a ¼ - ½ teaspoon of a high quality sea salt or sodium/potassium powder to a glass of water works wonders; however you may still require a separate magnesium supplement; particularly if you are prone to muscle cramps or restless legs. Another popular way to manage your electrolytes is via a good quality bone broth powder. Finally, since BHB’s are normally delivered via a mineral salt base*, keto flu symptoms are easily prevented or reduced by using an exogenous ketone supplement powder.
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*:
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.

Exogenous Ketones have been shown in performance studies of both humans and animals to improve metabolic efficiency, which in essence means that your body is using better fuel that burns more efficiently over longer periods of time, and decreases the amount of fuel you need while performing. Where glucose fails (glycogen depletion), ketones pick up the slack!
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
The chart below shows my ketone and glucose response to consuming 40g of KetoneAid’s ketone esters, which had been calculated to be my optimal serving size based on my weight (170lbs) and type of activity (I am moderately active/athletic, but cognitive experiments are a “low” physical activity). Normally, for increased physical performance ketone esters are consumed along with some glucose, but since I was only focusing on cognitive performance I did not consume any glucose.
This fasting process will not only activate autophagy in your cells, it will also increase your ketones much more quickly than if you were just eating a standard ketogenic diet. If you start implementing intermittent fasting and activities (like walking, cycling, or lifting weights) together, you can raise ketone levels and increase autophagy more than you would with intermittent fasting alone. This suggests that intermittent fasting would be a great addition to your life, but it is important to be familiar with the negative symptoms that can arise before you start.

We demonstrated that therapeutic ketosis could be induced without dietary (calorie or carbohydrate) restriction and that this acute elevation in blood ketones was significantly correlated with a reduction in blood glucose (Figs. 2, ​,33 and ​and4).4). The BMS ketone supplement did not significantly induce blood hyperketonemia or reduced glucose in the rats. The KE supplemented rats trended towards reduced glucose levels; however, the lower dose of this agent did not lower glucose significantly, as reported previously in acute response of mice [59]. MCTs have previously been shown to elicit a slight hypoglycemic effect by enhancing glucose utilization in both diabetic and non-diabetic patients [86–88]. Kashiwaya et al. demonstrated that both blood glucose and blood insulin decreased by approximately 50 % in rats fed a diet where 30 % of calories from starch were replaced with ketone esters for 14 days, suggesting that ketone supplementation increases insulin sensitivity or reduced hepatic glucose output [89]. This ketone-induced hypoglycemic effect has been previously reported in humans with IV infusions of ketone bodies [90, 91]. Recently, Mikkelsen et al. showed that a small increase in βHB concentration decreases glucose production by 14 % in post-absorptive health males [92]. However, this has not been previously reported with any of the oral exogenous ketone supplements we studied. Ketones are an efficient and sufficient energy substrate for the brain, and will therefore prevent side effects of hypoglycemia when blood levels are elevated and the patient is keto-adapted. This was most famously demonstrated by Owen et al. in 1967 wherein keto-adapted patients (starvation induced therapeutic ketosis) were given 20 IU of insulin. The blood glucose of fasted patients dropped to 1–2 mM, but they exhibited no hypoglycemic symptoms due to brain utilization of ketones for energy [93]. Therefore, ketones maintain brain metabolism and are neuroprotective during severe hypoglycemia. The rats in the MCT group had a correlation of blood ketone and glucose levels at week 4, whereas the combination of BMS + MCT produced a significant hypoglycemic correlation both at baseline and at week 4. No hypoglycemic symptoms were observed in the rats during this study. Insulin levels were not measured in this study; however, future ketone supplementation studies should measure the effects of exogenous ketones on insulin sensitivity with a glucose tolerance test. An increase in insulin sensitivity in combination with our observed hypoglycemic effect has potential therapy implications for glycemic control in T2D [40]. Furthermore, it should be noted that the KE metabolizes to both AcAc and βHB in 1:1 ratio [29]. The ketone monitor used in this study only measures βHB as levels of AcAc are more difficult to measure due to spontaneous decarboxylation to acetone; therefore, the total ketone levels (βHB + AcAc) measured were likely higher, specifically for the KE [14]. Interestingly, the 10 g/kg dose produced a delayed blood βHB peak for ketone supplements MCT and BMS + MCT. The higher dose of the ketogenic supplements elevated blood levels more substantially, and thus reached their maximum blood concentration later due to prolonged metabolic clearance. It must be noted that the dosage used in this study does not translate to human patients, since the metabolic physiology of rats is considerably higher. Future studies will be needed to determine optimal dosing for human patients.

It is important to define what it means to be “in ketosis”. If being “in ketosis” means having ketones in your blood, then of course ketone supplements get you into ketosis. But that is different from being in an endogenous ketogenic, fat-burning state as a result of following a ketogenic diet. Getting this distinction right will go a long way towards stopping ketone salts companies from using misleading marketing about the issue. We need to reach a consensus about what being “in ketosis” means and then force companies to use that definition.
If the claims about the benefits of exogenous ketones are accurate and true, then it’s fantastic news for people who are looking to enhance their keto lifestyle and who have the money to spend. But two of our core values are trustworthiness and goodness, and it is important to us to test assumptions made by marketing claims and help make sure that people are getting what they are told they are getting when they spend money on a product.
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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