Ketogenesis is the metabolism of fatty acids by β-oxidation. 4 This process gives acetyl CoA which then leads to β-hydroxy-β-methyglutaryl-CoA (HMG-CoA) as seen below5. HMG-CoA converts into Acetoacetone which can switch back and forth to BHB. Acetoacetone to Acetone conversion is irreversible (on the left below). Acetoacetate and BHB (via acetoacetate) are used to produce energy when converted back into acetyl-CoA within a cell’s mitochondria whilst Acetone is excreted in the breath and urine.4
Funding. This work supported by an Industrial DPhil Fellowship to BS from the Royal Commission for the Exhibition of 1851. JM was supported by the EPSRC Doctoral Training Centre and Prize Fellowship; Ref: EP/M508111/1. The funding sources were not involved in the design, conduct or analysis of this study. TΔS Ltd. provided the ketone ester, ΔG®, and NTT DOCOMO Inc. provided the acetone meter for the study.
Let’s briefly discuss some organic chemistry. Two molecules that are “the same” but mirror images of each other (like your hands) are known as enantiomers, a type of spatial isomer. Beta hydroxybutyrate comes in two forms, D-β-hydroxybutyrate (“right-handed”) and L-β-hydroxybutyrate (“left-handed”). D-β-hydroxybutyrate is the form that is naturally produced in the body and is most bioavailable when taken exogenously.
Do I still follow a ketogenic diet? Not anymore. I was strict keto for 12 weeks – enough time to experiment and learn about it. I did enjoy parts (lots of fat!) but I don’t see it as a sustainable way of eating, nor did I benefit from it health or sports performance wise (more on this in an upcoming article). But, I was following a strict keto diet – sans carbs. I think if I were to follow a ketogenic diet AND incorporate a regular carb refeed then the results may be different.
Over five visits, participants (n = 16) consumed either 4.4−1 of βHB (2.2−1 or 395 mg/kg of KE; 1 mole of KE delivered 2 moles of d-βHB equivalents): twice whilst fasted, and twice following a standardized meal, or an isocaloric dextrose drink without a meal. To improve palatability, drinks were diluted to 500 ml with a commercially available, citrus flavored drink containing 65 kCal (5 g of carbohydrate) (Glaceau, UK). The dextrose drink was taste-matched using a bitterness additive (Symrise, Holzminden, Germany). The standard meal consisted of porridge oats (54 g), semi-skimmed milk (360 ml) and banana (120 g), giving 600 kCal per person, with a macronutrient ratio of Carbohydrate: Protein: Fat of 2:1:1.
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?
Exogenous ketones have a wide range of benefits that can enhance your fat-burning lifestyle. I personally use them daily as a strategy to heighten my mental performance and give my workouts an extra boost. For these purposes, I have also found it logical to combine exogenous ketones with other known health and performance boosting agents such as branched-chain amino acids and medicinal mushrooms.

Interestingly, the effects of exogenous ketones on blood substrate concentrations were preserved with the metabolic stimulus of a mixed meal. Following KE drinks, FFA and glucose fell and remained low in both fed and fasted subjects, despite higher insulin throughout the fed arm, suggesting that there was no synergistic effect of insulin and βHB to further lower blood glucose or FFA. In agreement with previous work, the threshold for the effects of βHB on glucose and lipids appears to be low (<1 mM), as there was no significant dose-response relationship between increasing blood βHB and the small changes in plasma FFA, TG or glucose across all of the study drinks (Mikkelsen et al., 2015).
Some think so because higher ketone levels imply increased fuel for the brain and heart (that prefer ketones), and increased protection against inflammation and oxidation. But are the health benefits coming from the ketones themselves, or are they coming from the state you have to put your body in to actually produce them? And if you're kicking yourself out of ketosis by ingesting ketones would you still get the same benefits?
Several studies have investigated the safety and efficacy of ketone supplements for disease states such as AD and Parkinson’s disease, and well as for parenteral nutrition [40, 48–50, 100–103]. Our research demonstrates that several forms of dietary ketone supplementation can effectively elevate blood ketone levels and achieve deleted: therapeutic nutritional ketosis without the need for dietary carbohydrate restriction. We also demonstrated that ketosis achieved with exogenous ketone supplementation can reduce blood glucose, and this is inversely associated with the blood ketone levels. Although preliminary results are encouraging, further studies are needed to determine if oral ketone supplementation can produce the same therapeutic benefits as the classic KD in the broad-spectrum of KD-responsive disease states . Additionally, further experiments need to be conducted to see if the exogenous ketone supplementation affects the same physiological features as the KD (i.e. ROS, inflammation, ATP production). Ketone supplementation could be used as an alternative method for inducing ketosis in patients uninterested in attempting the KD or those who have previously had difficulty implementing the KD because of palatability issues, gall bladder removal, liver abnormalities, or intolerance to fat. Additional experiments should be conducted to see if ketone supplementation could be used in conjunction with the KD to assist and ease the transition to nutrition ketosis and enhance the speed of keto-adaptation. In this study we have demonstrated the ability of several ketone supplements to elevate blood ketone levels, providing multiple options to induce therapeutic ketosis based on patient need. Though additional studies are needed to determine the therapeutic potential of ketone supplementation, many patients that previously were unable to benefit from the KD may now have an alternate method of achieving therapeutic ketosis. Ketone supplementation may also represent a means to further augment ketonemia in those responsive to therapeutic ketosis, especially in those individuals where maintaining low glucose is important.

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.

So if you really want to jump start ketosis, do what the prehistoric humans did; don’t eat for 3 to 5 days. Keep the water bottle and multivitamins close and go on a strict fast. It might seem extreme and to a degree it is, but starving yourself will put you into ketosis. No ifs, ands, or buts about it. And it will cause you to lapse into a ketogenic state faster than if you tried to do so by manipulating the foods you eat (replacing carbs with fats). Once starvation has caused your body to transition to a ketogenic state, you can begin to introduce your low carb, high fat keto-friendly foods.

Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog or materials linked from this blog is at the user's own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.
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).
Obviously, cutting carbs is much easier than not eating anything at all for days on end. It's also safer for people with diabetes as it leads to a gradual decline in blood glucose [2]. The carbs you have to reduce are known as net carbs. Those are the carbs that your body uses to make glucose. You calculate them by subtracting the grams of fiber from total carbs in a food item.
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.
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 Pruvit’s Keto OS. You can check out our review here.
We’ve all been taught that high sodium intake is bad for us, similar to how we’ve been told for decades that fat is the driver of coronary heart disease, and consuming large amounts will kill us.  Sodium has been thought to increase blood pressure, and therefore increase the risk of heart disease, kidney disease, stroke, osteoporosis, and stomach cancer. Thus, many of us tend to avoid consuming foods or supplements with labels that have high amounts of sodium.
Supplemental BHB’s are ideal for people new to the ketogenic way of eating. The changes that happen in your brain and body when adapting to a VLC diet are both immediate and profound. For example, our kidney’s start processing minerals salts much more efficiently. Ironically, after years of being advised to decrease our intake of salt (sodium), it turns out that for people transitioning away from the Standard American Diet (SAD diet) towards a lower carb or ketogenic diet there is actually a need to increase dietary mineral salts such as potassium, sodium, magnesium and calcium. During the process of becoming keto-adapted, it is very important to increase your intake of these essential minerals, in order to prevent the onset of unpleasant symptoms (known as “keto flu”).
There are a couple factors that will make this look much more viable and achievable. For example, if you were to skip breakfast and have your first meal at 12PM, you could eat up until 8PM. This will also mean that dinner needs to be eaten slightly earlier. But let’s not forget about the fact that if we were to combine this with the 6-10 hours of sleep that you would normally have each night, that’ll take up the majority of your fasting period. Obviously, you’re not restricted to these hours, as everyone has a different schedule. Doesn’t sound as bad as you initially thought? Well let’s make it even more enticing! During your fasting hours, and this is extremely helpful during mornings up until you can have your first meal, non-caloric beverages such as tea and coffee can help starve away those hung pangs. Just make sure you’re taking these drinks on it’s own, without any added sugar or milk. There are many variations of intermittent fasting with the most common being 16/8. But depending on your schedule, there are other options advocated such as 20/4, 22/2, and if you’re crazy enough and can eat a full day’s worth of calories in one sitting then there is also OMAD (one meal a day).

Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog or materials linked from this blog is at the user's own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.

Until there is more definitive information on the necessary blood levels and the differing proportions of BOHB an AcAc to optimize cellular and organ functions, it will be difficult to specify the dosing and duration of supplemental ketones. However for fuel use, and very likely for exercise performance as well, sustained blood levels of BOHB in the range of 0.5 mM to 1.0 mM are likely to be required. This is achieved physiologically by an estimated ketone production of 50-100 grams per day in a keto-adapted human.
Elliot received his BS in Biochemistry from the University of Minnesota and has been a freelance writer specializing in nutritional and health sciences for the past 5 years. He is thoroughly passionate about exercise, nutrition, and dietary supplementation, especially how they play a role in human health, longevity, and performance. In his free time you can most likely find him lifting weights at the gym or out hiking through the mountains of Colorado. He will also host the upcoming BioKeto podcast. You can connect with him on Facebook ( and Instagram (@eazy_ell)
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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.
“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.”

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