A ketone is a molecule your liver makes from fat when you don’t eat for more than 72 hours, or if you follow a strict ketogenic diet. During these times, ketones are the main source of energy for your body.

Ketone supplements (also known as “exogenous ketones”) are marketed to enhance physical performance, weight loss, mental performance, and energy by raising ketone levels in the blood. Recently, ketone supplements have emerged as a potential alternative (or addition) to following a strict ketogenic diet in order to start or maintain nutritional ketosis (restricting carbohydrate intake to increase ketone production).

Despite marketing claims, very little scientific evidence exists to support the safety and effectiveness of ketone supplements.

Ketones found in dietary supplements are made in a laboratory, not by the body. Ketone supplements usually contain beta-hydroxybutyrate (BHB; a ketone), medium-chain triglycerides (MCTs, which your liver can make into BHB), or both, along with other ingredients. BHB is often combined with minerals such as sodium, potassium, calcium, or magnesium to form “ketone salts.” Other ketone supplements can be in liquid form and are usually referred to as “ketone esters.”

Possible side effects of ketone supplements include gastrointestinal upset, vomiting, diarrhea, and indigestion. BHB as a ketone salt might cause mild dehydration. Frequent or long-term consumption of ketone salts might have negative effects on blood pressure, but this has not yet been confirmed.

Ketone supplements must be taken at regular intervals to maintain increased blood ketone levels. This can be challenging because most ketone supplements don’t taste very good.

In general, very few reliable scientific studies have explored the effects of ketone supplements. A few clinical trials have used ketone supplements to increase blood ketone levels over the short term (less than one week). However, the evidence is mixed regarding the safety and effectiveness when used for physical performance. Most data come only from highly-trained endurance athletes and do not apply to military operations. There is very little scientific evidence regarding the safety and effectiveness of ketone supplements for any of the other marketed claims.

For more information, please read HPRC’s article about ketogenic diets.

Updated 01 June 2020


Avgerinos, K. I., Egan, J. M., Mattson, M. P., & Kapogiannis, D. (2020). Medium chain triglycerides induce mild ketosis and may improve cognition in Alzheimer’s disease. A systematic review and meta-analysis of human studies. Ageing Research Reviews, 58, Article 101001. doi:10.1016/j.arr.2019.101001

Burke, L. M. (2019). Supplements for optimal sports performance. Current Opinion in Physiology, 10, 156–165. doi:10.1016/j.cophys.2019.05.009

Cavaleri, F., & Bashar, E. (2018). Potential synergies of β-hydroxybutyrate and butyrate on the modulation of metabolism, inflammation, cognition, and general health. Journal of Nutrition and Metabolism, 2018, Article 7195760. doi:10.1155/2018/7195760

Clarke, K., Tchabanenko, K., Pawlosky, R., Carter, E., Todd King, M., Musa-Veloso, K., . . . Veech, R. L. (2012). Kinetics, safety and tolerability of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate in healthy adult subjects. Regulatory Toxicology and Pharmacology, 63(3), 401–408. doi:10.1016/j.yrtph.2012.04.008

Cox, Pete J., Kirk, T., Ashmore, T., Willerton, K., Evans, R., Smith, A., . . . Clarke, K. (2016). Nutritional ketosis alters fuel preference and thereby endurance performance in athletes. Cell Metabolism, 24(2), 256–268. doi:10.1016/j.cmet.2016.07.010

Dearlove, D. J., Faull, O. K., & Clarke, K. (2019). Context is key: Exogenous ketosis and athletic performance. Current Opinion in Physiology, 10, 81–89. doi:10.1016/j.cophys.2019.04.010

Egan, B., & D’Agostino, Dominic P. (2016). Fueling performance: Ketones enter the mix. Cell Metabolism, 24(3), 373–375. doi:10.1016/j.cmet.2016.08.021

Evans, M., Cogan, K. E., & Egan, B. (2017). Metabolism of ketone bodies during exercise and training: Physiological basis for exogenous supplementation. The Journal of Physiology, 595(9), 2857–2871. doi:10.1113/jp273185

Evans, M., & Egan, B. (2018). Intermittent running and cognitive performance after ketone ester ingestion. Medicine & Science in Sports & Exercise, 50(11), 2330–2338. doi:10.1249/mss.0000000000001700

Evans, M., McSwiney, F. T., Brady, A. J., & Egan, B. (2019). No benefit of ingestion of a ketone monoester supplement on 10-km running performance. Medicine & Science in Sports & Exercise, 51(12), 2506–2515. doi:10.1249/mss.0000000000002065

Evans, M., Patchett, E., Nally, R., Kearns, R., Larney, M., & Egan, B. (2018). Effect of acute ingestion of β-hydroxybutyrate salts on the response to graded exercise in trained cyclists. European Journal of Sport Science, 18(3), 376–386. doi:10.1080/17461391.2017.1421711

Fomin, D. A., & Handfield, K. (2020). The ketogenic diet and dermatology: A primer on current literature. Cutis, 105(1), 40–43.  Retrieved from https://mdedge-files-live.s3.us-east-2.amazonaws.com/files/s3fs-public/Fomin%20CT105001040.PDF

Gershuni, V. M., Yan, S. L., & Medici, V. (2018). Nutritional ketosis for weight management and reversal of metabolic syndrome. Current Nutrition Reports, 7(3), 97–106. doi:10.1007/s13668-018-0235-0

Gross, E., Putananickal, N., Orsini, A.-L., Schmidt, S., Vogt, D. R., Cichon, S., . . . Fischer, D. (2019). Efficacy and safety of exogenous ketone bodies for preventive treatment of migraine: A study protocol for a single-centred, randomised, placebo-controlled, double-blind crossover trial. Trials, 20(1), Article 61. doi:10.1186/s13063-018-3120-7

Harvey, C. J. d. C., Schofield, G. M., & Williden, M. (2018). The use of nutritional supplements to induce ketosis and reduce symptoms associated with keto-induction: A narrative review. PeerJ, 6, Article e4488. doi:10.7717/peerj.4488

Harvey, K. L., Holcomb, L. E., & Kolwicz, S. C. (2019). Ketogenic diets and exercise performance. Nutrients, 11(10), Article 2296. doi:10.3390/nu11102296

Kanikarla-Marie, P., & Jain, S. K. (2016). Hyperketonemia and ketosis increase the risk of complications in type 1 diabetes. Free Radical Biology and Medicine, 95, 268–277. doi:10.1016/j.freeradbiomed.2016.03.020

Kovács, Z., D’Agostino, D. P., Diamond, D., Kindy, M. S., Rogers, C., & Ari, C. (2019). Therapeutic potential of exogenous ketone supplement induced ketosis in the treatment of psychiatric disorders: Review of current literature. Frontiers in Psychiatry, 10, Article 363. doi:10.3389/fpsyt.2019.00363

LaFountain, R. A., Miller, V. J., Barnhart, E. C., Hyde, P. N., Crabtree, C. D., McSwiney, F. T., . . . Volek, J. S. (2019). Extended ketogenic diet and physical training intervention in military personnel. Military Medicine, 184(9-10), e538–e547. doi:10.1093/milmed/usz046

Margolis, L. M., & O'Fallon, K. S. (2019). Utility of ketone supplementation to enhance physical performance: A systematic review. Advances in Nutrition, 11(2), 412–419. doi:10.1093/advances/nmz104

O’Malley, T., Myette-Cote, E., Durrer, C., & Little, J. P. (2017). Nutritional ketone salts increase fat oxidation but impair high-intensity exercise performance in healthy adult males. Applied Physiology, Nutrition, and Metabolism, 42(10), 1031–1035. doi:10.1139/apnm-2016-0641

Pinckaers, P. J. M., Churchward-Venne, T. A., Bailey, D., & van Loon, L. J. C. (2016). Ketone bodies and exercise performance: The next magic bullet or merely hype? Sports Medicine, 47(3), 383–391. doi:10.1007/s40279-016-0577-y

Poffé, C., Ramaekers, M., Thienen, R., & Hespel, P. (2019). Ketone ester supplementation blunts overreaching symptoms during endurance training overload. The Journal of Physiology, 597(12), 3009–3027. doi:10.1113/jp277831

Rodger, S., Plews, D., Laursen, P., & Driller, M. W. (2017). Oral β-hydroxybutyrate salt fails to improve 4-minute cycling performance following submaximal exercise. Journal of Science and Cycling, 6(1), 26–31.  Retrieved from https://hdl.handle.net/10289/11199

Sansone, M., Sansone, A., Borrione, P., Romanelli, F., Di Luigi, L., & Sgrò, P. (2018). Effects of ketone bodies on endurance exercise. Current Sports Medicine Reports, 17(12), 444–453. doi:10.1249/jsr.0000000000000542

Sass, J. O. (2011). Inborn errors of ketogenesis and ketone body utilization. Journal of Inherited Metabolic Disease, 35(1), 23–28. doi:10.1007/s10545-011-9324-6

Scott, J. M., & Deuster, P. A. (2016). Ketones and human performance. Journal of Special Operations Medicine, 17(2), 112–116.

Shaw, D. M., Merien, F., Braakhuis, A., Plews, D., Laursen, P., & Dulson, D. K. (2019). The effect of 1,3-butanediol on cycling time-trial performance. International Journal of Sport Nutrition and Exercise Metabolism, 29(5), 466–473. doi:10.1123/ijsnem.2018-0284

Sonnenburg, R. (2018). Examining the Effects of Exogenous Ketones on Exercise Metabolism and Performance in Male Varsity Athletes. (MS), University of Waterloo, Waterloo, Ontario, Canada. Retrieved from http://hdl.handle.net/10012/13356 

Soto-Mota, A., Vansant, H., Evans, R. D., & Clarke, K. (2019). Safety and tolerability of sustained exogenous ketosis using ketone monoester drinks for 28 days in healthy adults. Regulatory Toxicology and Pharmacology, 109, Article 104506. doi:10.1016/j.yrtph.2019.104506

Stubbs, B. J., Cox, P. J., Evans, R. D., Santer, P., Miller, J. J., Faull, O. K., . . . Clarke, K. (2017). On the metabolism of exogenous ketones in humans. Frontiers in Physiology, 8, Article 848. doi:10.3389/fphys.2017.00848

Urbain, P., Strom, L., Morawski, L., Wehrle, A., Deibert, P., & Bertz, H. (2017). Impact of a 6-week non-energy-restricted ketogenic diet on physical fitness, body composition and biochemical parameters in healthy adults. Nutrition & Metabolism, 14, Article 17. doi:10.1186/s12986-017-0175-5

Valenzuela, P. L., Morales, J. S., Castillo-García, A., & Lucia, A. (2020). Acute ketone supplementation and exercise performance: A systematic review and meta-analysis of randomized controlled trials. International Journal of Sports Physiology and Performance, 15(3), 298–308. doi:10.1123/ijspp.2019-0918

Van Rijt, W. J., Heiner-Fokkema, M. R., du Marchie Sarvaas, G. J., Waterham, H. R., Blokpoel, R. G. T., van Spronsen, F. J., & Derks, T. G. J. (2014). Favorable outcome after physiologic dose of sodium-D,L-3-hydroxybutyrate in severe MADD. Pediatrics, 134(4), e1224–e1228. doi:10.1542/peds.2013-4254

Vanitallie, T. B., & Nufert, T. H. (2003). Ketones: Metabolism's ugly duckling. Nutrition Reviews, 61(10), 327–341. doi:10.1301/nr.2003.oct.327-341

White, H., & Venkatesh, B. (2011). Clinical review: Ketones and brain injury. Critical Care, 15(2), Article 219. doi:10.1186/cc10020