In Study 2 a Student's unequal variance t-test with equal SD was used to compare urine βHB concentrations. Additionally, a linear mixed effects model was constructed to estimate partitions of variance in R, using the lme4 and blme packages (Chung et al., 2013; Bates et al., 2015). Feeding state and visit number were fixed effects in this model, and inter-participant variability was a random effect. Inter-participant variability was calculated according to the adjusted generalized R2 metric (as proposed by Nakagawa and Schielzeth, 2013), to partition variance between the fixed effects of feeding, inter-participant variability, and residual variability. The coefficient of variation for βHB Cmax and AUC were calculated using the method of Vangel (1996).
Another source of the D-BOHB isomer is an evolutionarily ancient energy source for micro-organisms. Poly-BOHB is a long chain of D-BOHB molecules strung end-to-end. It functions in many single-cell organisms as a concentrated energy source similar to glycogen in mammals, but whereas glycogen breakdown releases individual glucose molecules, poly-BOHB hydrolysis releases single D-BOHB molecules.
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.
Ketones are also a cleaner-burning fuel than carbs. They’re burned for energy in the mitochondria, and fewer free radicals (a highly-reactive, short-lived uncharged molecule) are generated when compared to burning glucose.15 What’s more, ketone molecules themselves cause a decrease in production of free radicals,21,22 while also increasing glutathione–a powerful antioxidant protecting against mitochondrial damage induced by free radicals.23

When you restrict carbs, the kidneys excrete a lot of sodium. Not replacing this sodium can leave you feeling light headed. I recommend having a big glass of spring water with ½ teaspoon of Celtic sea salt twice a day (first thing in the morning and midafternoon are two times that work well). A long with this, make sure you use a lot of salt on your meals.

A small side effect for some people is “ketosis breath”. Many people on a ketogenic diet have experienced this temporary phenomenon, and those taking exogenous ketones can experience it as well. The smell of your breath when you are early in the ketogenic diet can have a hint of acetone to it, and it might be mildly unpleasant, but it’s also harmless. Most gum is pretty low in carbohydrates and is a great option while your keto breath fades.
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.)
In addition to the Weir coefficients being potentially off (which impacts EE), the RQ interpretation may be incorrect in the presence of endogenous or exogenous ketones. As a result, the estimation of fat and glucose oxidation may be off (though it’s directionally correct). That said, the current interpretation seems quite plausible—greater fat oxidation when I had to make my ketones; less when I got my ketones for “free.”
If you truly want to optimize health and performance, magnesium should not be neglected. There is still more research to be done on its potential. Good sources of magnesium include whole grains, nuts, seeds, legumes, green leafy vegetables, and supplements. However, be careful about taking too much magnesium at one time, or else you might end up running to the bathroom in a hurry.

When choosing an exogenous ketone supplement, make sure to read the ingredients carefully. Brands that have a “proprietary blend” don’t allow you to see the quantities of each ingredient in their mix. You should know every detail about the supplements you choose, so you know exactly what is affecting your body, and you have control over the variables of your intake.
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.
The table below shows the same measurements and calculations as the above table, but under the test conditions. You’ll note that BHB is higher at the start and falls more rapidly, as does glucose (for reasons I’ll explain below). HR data are almost identical to the control test, but VO2 and VCO2 are both lower. RQ, however, is slightly higher, implying that the reduction in oxygen consumption was greater than the reduction in carbon dioxide production.
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.
Ketōnd is an intelligently designed formula containing an industry leading 13,900mg blend of high-powered goBHB™ all packed into a 100% transparent, proprietary blend free formula. Ketōnd is widely known as the most ‘potent’ exogenous ketone supplement available that has been formulated for anyone looking to manage their weight, maximize cognition, or simply feel more energetic in a low carbohydrate environment.
Venous blood samples (2 ml) were obtained during all visits using a 22 G catheter inserted percutaneously into an antecubital vein. The catheter was kept patent using a saline flush following each sample collection. Additionally, during Study 1, arterialized blood from a catheter inserted into a heated hand (Forster et al., 1972) was collected into heparinized blood gas syringes (PICO 100, Radiometer, Copenhagen) from a subset of participants (n = 7) and immediately analyzed for pH and electrolytes using a clinical blood gas analyser (ABL, Radiometer, Copenhagen).

The product does not work. I have taken one scoop daily and for last two days two scoops (once in the morning and once in the night). I also do intermittent fast i.e. no food from 8 pm - next day 2 pm other than this powder in the morning. My food is 1500 calories with 60% fat, 30% protein and 5% carbs. I used to achieve ketosis naturally prior to using the powder. But now, there is no ketosis. This product does not work. I am wondering how on earth did they pick up so many reviews, unless it is faked marketing.
Ketone supplements: are they a groundbreaking boost to a low-carb diet, or should you be wary of the broad claims that companies make about their benefits? In this article you’ll learn all about exogenous ketone supplements and, what’s more, you’ll read about the experiment we ran on the supplements at our head office in Stockholm. How did ketone supplements perform when we put them to the test? Do they work? Read on to find out our verdict!
It was like getting the benefits of a five-day fast in just 15 minutes! As my body and brain began sucking up the ketones, I felt a rush of energy and my mind became very sharp and focused in ways beyond what I attain doing an extended fast. But in this case it was the 40g of ketones I had just consumed. Even at the two-hour mark, when I took my last reading, I was still in deep ketosis.
EK use can be compared to the nootropics that have been developed for optimizing focus, memory creation, and faster cognitive performance. While you may not notice this effect on a minute to minute basis if you keep a journal of “forgetful moments” you’ll find that you have fewer of them as time goes on. You’ll also find that you’re able to come up with better ideas, and your workflow is more efficient through the day (10, 11).
Most of the information regarding the effects of ketosis come from studies on the ketogenic diet, wherein ketones are made by the liver and become a major fuel source for the body. The ketogenic diet is currently under investigation for its potential therapeutic effects in a number of healthy and disease states. More recently, studies are beginning to reveal that many of the effects observed with the ketogenic diet are mechanistically attributable to ketones, which is a primary reason that exogenous ketones are being developed and studied. However, because they are such a new technology, there’s not a lot of data on exogenous ketones themselves. In a few pre-clinical studies, exogenous ketones have mimicked the therapeutic effects of the ketogenic diet”
Blood d-βHB, pH, bicarbonate (HCO3-) and electrolytes measured in arterialized blood samples from resting subjects (n = 7) following a ketone ester or salt drink containing 3.2−1 of βHB. Shaded areas represent the normal range. Values are means ± SEM. (A) Venous blood d-βHB. (B) Arterialized blood pH. (C) Blood bicarbonate. (D) Blood potassium. (E) Blood sodium. (F) Blood chloride. †p < 0.05 difference between KE and KS, *p < 0.05 difference from baseline value.
If you stop eating carbs, your body first uses up glucose reserves stored in the liver and muscles. After it burns all that's left of glucose, it has no other options but to start burning fat. It can burn either your body's fat stores or the fat you eat. However, not all cells in your body can use fat to make energy and this is where ketones come into play.

Another source of the D-BOHB isomer is an evolutionarily ancient energy source for micro-organisms. Poly-BOHB is a long chain of D-BOHB molecules strung end-to-end. It functions in many single-cell organisms as a concentrated energy source similar to glycogen in mammals, but whereas glycogen breakdown releases individual glucose molecules, poly-BOHB hydrolysis releases single D-BOHB molecules.
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*:
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.
How BHB turns into energy is a fairly simple process. As we’ve mentioned, beta hydroxybutryate eventually leads to energy production after you consume it or after your body breaks stored body fat down. It does this by going into the cell, entering the mitochondria (energy factories) at which stage it cleaves the carboxyl acid group and becomes acetoacetate (another “ketone body”). Acetoacetate turns into acetoacetyl-CoA, which then is cleaved to acetone (another “ketone body”) and acetyl-CoA. Acetyl-CoA is the whole reason we want BHB in the first place. This jumps into what is called the Kreb’s cycle (don’t you remember any of your biochemistry classes?) and is churned into ATP — the energy currency of your cells!
Eating around 20 grams of net carbs a day is as a foolproof way to get you into ketosis a quickly as is humanly possible. However, having 50 grams of total carbs will also get you into ketosis within three days [3]. This amount of carbs is enough to deplete glucose reserves. It's also low enough to prevent fat being used to make glucose and, instead, the body is forced to make ketones.

Fasting blood samples were collected prior to all interventions. Following consumption of study drinks (details below), blood, expired gas and urine samples were collected at regular intervals for 4 h. Water was freely permitted and participants remained sedentary at the test facility throughout the visit. A subset of participants returned for samples 8 and 24 h after the ketone drinks (Study 1).
The best time to start a one day fast is in the evening (neither morning nor the night) – preferably, around 6 pm. It won’t make you lose your vital energy during the daytime workouts, nor does it let you sleep with undigested foodstuff in your stomach. Taking late meals and sleeping with undigested food doesn’t allow your body to rest. So the natural healing mechanism of your body fails during the sleep time as the entire resources are busy digesting your food.
Keto-adaption is a complex set of metabolic processes in which the body shifts from using primarily glucose for energy to using largely ketones and fat for energy. Achieving ketosis doesn’t mean the body is maximizing the use of these ketones; it takes longer than a few days for the body to get used to burning fat and ketones as its predominant fuels.
About the only other negative thing I have heard about the company is that if you are placing an order over the phone, they don’t answer too many questions. Instead, they refer you to their website. Their website is very informative and pretty much answers any question you might have. Ketōnd has gotten too popular, and the company had to hire an answering service like they are selling George Forman Grills or something to take calls from around the world 24-7. I know it’s popular all over Europe and Australia too. My buddies that compete in Crossfit swear that this stuff gives them the edge.
The culprit is often restaurant meals or other meals where the nutrition facts are not available with the food itself. Such “ignorance is bliss” situations allow us to avoid dealing with daunting numbers. Many people don’t hesitate to stop and enjoy a meal at a restaurant, but they freak out when they actually see the numbers on a label.  By now, we all know that opting for fatty meat with a side of veggies cooked in butter isn’t that bad after all.  It turns out that what you thought to be the safe, “healthy,” doctor-approved choice might not always be what you think it is.
If you have tried other ketone supplements that haven’t worked as promised or tasted terrible. Have no fear. This stuff is what a ketone supplement should be. It’s incredible what customers tell me. How it’s given them more energy, focus, drive. Helped them lose weight and suppress their appetite. Help them train harder at the gym and all kinds of great stories.*
It’s hard to say. Achieving a natural state of ketosis (as in, by eating a ketogenic diet) is thought to be beneficial in the short-term. But experts don’t know the long-term effects, Palumbo says. And some suspect that it could lead to problems like kidney damage or an increased risk for heart disease (and day-to-day keto diet side effects are, at this point, well-documented). Assuming that ketone supplements do work identically to natural ketones, taking them long-term could have similar health effects.
Ketones are an alternate energy or fuel source for brain and body that our bodies have naturally produced and used for millennia. Ketones have recently leapt to the forefront of health and wellness conversations worldwide as the scientific body of research that seeks to understand their numerous unique properties and profound systemic effects has begun to grow (see below).
The current USDA recommendations reflect “unachievable goals” that do not match what research suggests our normal physiological ranges might be[10]. There is not enough evidence to show that sodium restriction is associated with less mortality or cardiovascular morbidity in healthy individuals or individuals with high blood pressure, and there is evidence that sodium restriction might actually be harmful to individuals with heart failure[11]. For serious athletes, and individuals who are active daily, the current recommendations might not only be unwise but unsafe. If you are eating a carbohydrate-restricted diet, this applies to you even more. Don’t stress about the high amounts of sodium in a lot of these ketone supplements, being that they allow for a fast delivery of ketones to the body, which has unique benefits that will be discussed in a separate article.  Instead, change out the frozen dinner and experiment with an effective dose of exogenous ketones.
Great information. And apparently I have found out what my problem is. I got into Keto a few weeks ago. Transitioned into ketosis after a week, and then had to travel….while I followed a keto diet as best I could, (I took your powdered MCT Oil with me and it is great), but I did fall out of ketosis. Now it’s been 2 weeks and I can’t seem to get back into ketosis.
Ketone supplements contain exogenous ketones—synthetic ketones made in a lab. Most use a type of ketone called beta-hydroxybutyrate (BHB), which is the same as the ketones the body produces naturally. “We’re literally biohacking," says Amie Heverly, who began taking a ketone supplement called Prüvit last year and now works as a promoter selling Prüvit products. "You’re not adding a foreign substance to your body, because BHB is identical to what your body would naturally produce,” she explains.

“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.”

Affiliate Disclosure: There are links on this site that can be defined as affiliate links. This means that I may receive a small commission (at no cost to you) if you purchase something when clicking on the links that take you through to a different website. By clicking on the links, you are in no way obligated to buy.

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.

Copyright ©