Note: The U.S. Food and Drug Administration (FDA) does not approve supplements for safety or effectiveness. Talk to a healthcare professional about whether a supplement is the right fit for your individual health, and about any potential drug interactions or safety concerns.
By now, you’ve probably heard of the ketogenic diet — often called “keto” by its devoted followers. The main promise of the popular nutrition approach is fast weight loss.
“What happens when you deprive your body of carbohydrates is that your body uses fat as energy,” says Abby Langer, RD, the Toronto-based founder of a company that helps people learn about and implement healthy nutrition habits. When the body digests this much fat, it produces by-products called ketone bodies and enters a state called ketosis, which means the body recruits fat rather than carbohydrates to fuel its functions.
The problem is, it’s hard to maintain ketosis. “Anytime you go over [about] 50 grams (g) of carbohydrates, you’re going to kick yourself out of ketosis and the weight is going to come back,” Langer says.
That’s where some people turn to supplements. “Exogenous ketones are lab-made compounds that mimic the natural ketones your body produces during fasting or when you’re on a very low-carb diet,” says Michael Ednie, MD, RD, the chief medical officer of Bespoke Concierge MD in Scottsdale, Arizona.
Potential Benefits of Exogenous Ketones
The research on exogenous ketone supplements is mixed and limited. While some small, early studies point toward possible health perks, experts still don’t have enough evidence to fully endorse these.
“While the research on exogenous ketones is intriguing, I believe it’s still far from conclusive,” says Hector Perez, MD, a bariatric surgeon at Renew Bariatrics in Tijuana, Mexico. “There are a handful of small trials, some with only 15 to 20 healthy participants, which are not enough to justify sweeping recommendations.”
Keeping that in mind, here’s what some of that research has found thus far.
May Boost Cognition
“Some early data suggests potential cognitive or neurological benefits, possibly because ketones offer a cleaner fuel source for the brain,” says Dr. Ednie.
Although the brain usually uses glucose for energy, it switches to ketones when glucose levels are low. Since ketones don’t need insulin or certain transporters to reach brain cells, they can be helpful when not enough glucose is available. Research shows that insulin resistance harms brain activity, reducing communication between brain cells, but many of these brain functions improve when ketones are added (particularly memory-related activity). The study was conducted on mice, however, so human studies are needed.
“Early human studies are encouraging and show real promise, but the sample sizes are small and longer-term effects are still being studied,” says Dr. Perez. “It could be helpful for those with cognitive sluggishness, but it’s not a wonder focus pill for the healthy.”
It’s worth noting that research on humans indicates that a keto diet that doesn’t include ketone supplements may also benefit cognitive function such as memory and attention.
May Support Exercise Endurance
Exogenous ketone supplements may theoretically boost endurance in athletes by increasing erythropoietin, a hormone that supports the body in delivering oxygen to muscles. But some research shows mixed results that may be partly due to inconsistencies between individual subjects and a lack of long-term data.
“Ketones improve cardiac efficiency and may support muscle recovery, especially under metabolic stress, but performance boosts seem inconsistent,” says Perez. “There is strong mechanistic data from both animal and cellular models, but clinical trial results in athletes seem context-dependent.”
In other words, athletic performance may not improve for everyone who takes this supplement. “Some athletes report enhanced endurance; others see no difference — or even negative effects,” Ednie adds.
A systematic review that evaluated 16 performance outcomes of ketone supplementation from 10 studies reported three studies showed positive effects, three studies showed negative effects, and the remaining studies didn’t show any meaningful change in either direction. The discrepancies in the data may be partly due to differences in the type of supplement, dose, and performance tests between the studies, but the authors concluded that there isn’t enough evidence to recommend ketone supplements to increase performance.
May Lower Blood Sugar
One review conducted in Canada showed that ketone supplements, particularly ketone esters, lowered blood sugar in healthy people, those with obesity, and those with prediabetes or type 2 diabetes. This may be due to a combination of factors, including their ability to decrease how much glucose the liver makes and their stimulation of insulin release.
“Exogenous ketone esters acutely lower blood glucose, even without insulin, which can be useful in insulin-resistant or post-op patients needing rapid stabilization,” says Perez. “The evidence for short-term glucose reduction is strong and well-documented in controlled human trials, but there’s still limited research on long-term results.”
Weight Loss Effect of Exogenous Ketones
Some research points toward the potential benefits of exogenous ketones for managing hunger levels, but the studies were small and had mixed results.
For example, one study of 10 healthy young men found that a ketone drink decreased levels of ghrelin, a hormone that triggers hunger, by about 25 percent, lowering appetites.
Another small study, in Germany, involved a one-day fast with just eight participants ages 20 to 35, and found that exogenous ketone supplements didn’t help manage weight or appetite control when paired with a normal diet.
“This is not high-quality, large-scale research yet,” says Ednie. “These are pilot studies and reviews that raise good questions but don’t give us definitive answers. The takeaway is curiosity, not certainty — these supplements aren’t a quick fix, and more rigorous trials are needed.”
It’s important to keep in mind that exogenous ketones are not a definitive or long-term solution for weight loss.
“If you're curious, talk to your doctor, especially if you’re managing diabetes, appetite dysregulation, or trying to optimize performance,” says Perez. “But don’t mistake these early findings for proof that ketone drinks can replace real dietary change or medical treatment. The science [may seem] promising, but [it's] still young.”
Potential Risks and Side Effects of Exogenous Ketones
Risks
Ketone salts can be high in sodium or other electrolytes. “This might raise concerns for those with blood pressure or kidney issues,” says Ednie. Too much salt in your blood can increase your blood pressure and put a strain on your kidneys as they filter the excess.
There’s also a misconception that popping these supplements will put you into “fat-burning mode,” but that’s not true.
“They increase blood ketone levels temporarily but don’t trigger the same metabolic changes that happen during real ketosis,” says Ednie. “So for weight loss or metabolic health, they’re not a replacement for nutrition or exercise.”
These supplements also interact with blood sugar, which means they could alter how your medications work, says Ednie, so always speak to your doctor about possible interactions before starting a new supplement.
”Use them with caution, and never as a shortcut,” says Perez.
Side Effects
The most common side effects of exogenous ketones are gut-related, says Ednie. This may include nausea, bloating, gas, or diarrhea.
“Some people also feel jittery or tired after taking them,” he says.
Forms of Exogenous Ketones
Exogenous ketones often come in powdered form. There are two common types: ketone esters and ketone salts. Ketone esters work faster and better than ketone salts, if you can stomach the flavor and higher cost.
“Ketone esters are more potent, but expensive and hard to tolerate taste-wise,” says Ednie. “Ketone salts are more affordable and palatable, but often high in sodium.”
People also use medium-chain triglyceride (MCT) oil or powders to induce ketosis, and while not technically a type of exogenous ketone, some take MCTs separately or alongside ketone supplements. MCTs absorb differently than longer-chain fatty acids because they are smaller and water soluble, making them more readily available to be oxidized to become ketone bodies rather than stored as body fat.
How to Select and Store Exogenous Ketones
Selection
“Be cautious of any brand that overpromises, especially those claiming fast weight loss or extreme cognitive boosts,” says Ednie. “If the label is vague or sounds too good to be true, move on.”
While the U.S. Food and Drug Administration (FDA) doesn’t check supplements for safety or effectiveness before they’re sold, some independent organizations offer third-party testing to ensure the product was properly manufactured and contains the ingredients listed on the label. To choose a quality supplement, check the label for approval by USP, NSF, or ConsumerLab.com.
Storage
Keep exogenous ketones in a cool, dry place away from direct sunlight and heat.
“Heat degrades ketone esters and salts quickly,” says Perez. Avoid moisture, as it can cause clumping and spoilage in powders. Always seal tightly after use.
Refrigeration isn’t usually required, though it can extend the shelf life for some formulations. Check the manufacturer’s guidelines.
Dosage of Exogenous Ketones
Speak to your doctor before starting exogenous ketones or any other supplement to ensure they’re right for you and to get guidance on the dose, how long to take it, and what side effects to look for.
There’s no universal guideline for dosing, but most studies use between 10 and 25 g of ketone ester. That’s a big range, so if these supplements get the green light from your doctor, Ednie recommends starting with a small dose first to see how your body responds.
The Takeaway
Exogenous ketones are lab-made compounds that mimic the natural ketones your body produces during fasting or when you’re on a very low carb diet.
Exogenous ketones aren’t a shortcut for losing weight, and there isn’t yet clear evidence saying these supplements can help with healthy weight loss.
While early research shows exogenous ketones may offer potential benefits such as lowering blood sugar, improving cognition, or increasing athletic performance, the evidence is far from definitive or conclusive.
Always speak to your doctor before starting any supplement, including exogenous ketones, as they can interact with certain medications or cause side effects like gastrointestinal distress.
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
Falkenhain K et al. Exogenous Ketone Supplementation: An Emerging Tool for Physiologists With Potential as a Metabolic Therapy. Experimental Physiology. December 19, 2022.
Chinna-Meyyappan A et al. Effects of the Ketogenic Diet on Cognition: A Systematic Review. Nutritional Neuroscience. December 2023.
Sitko S. The Role of Exogenous Ketones in Road Cycling: Evidence, Mechanisms, and Performance Claims. Physiologia. November 24, 2024.
Margolis LM et al. Utility of Ketone Supplementation to Enhance Physical Performance: A Systematic Review. Advances in Nutrition. October 5, 2019.
Vestergaard ET et al. Acute Ketosis Inhibits Appetite and Decreases Plasma Concentrations of Acyl Ghrelin in Healthy Young Men. Diabetes, Obesity and Metabolism. April 14, 2021.
Hägele FA et al. Impact of One-Day Fasting, Ketogenic Diet or Exogenous Ketones on Control of Energy Balance in Healthy Participants. Clinical Nutrition ESPEN. June 1, 2023.
Howland J. Mayo Clinic Minute: Can Extra Salt Hurt Your Kidneys? Mayo Clinic. March 17, 2025.
Stubbs BJ et al. Daily Consumption of Ketone Ester, Bis-Octanoyl (R)-1,3-Butanediol, Is Safe and Tolerable in Healthy Older Adults in a Randomized, Parallel Arm, Double-Blind, Placebo-Controlled, Pilot Study. Journal of Nutrition, Health, and Aging. September 1, 2024.
Mohib O et al. Clinical Benefits of Exogenous Ketosis in Adults with Disease: A Systematic Review. Nutrients. September 30, 2025.
Justin Laube, MD, is a board-certified integrative and internal medicine physician, a teacher, and a consultant with extensive expertise in integrative health, medical education, and trauma healing.
He graduated with a bachelor's in biology from the University of Wisconsin and a medical degree from the University of Minnesota Medical School. During medical school, he completed a graduate certificate in integrative therapies and healing practices through the Earl E. Bakken Center for Spirituality & Healing. He completed his three-year residency training in internal medicine at the University of California in Los Angeles on the primary care track and a two-year fellowship in integrative East-West primary care at the UCLA Health Center for East-West Medicine.
He is currently taking a multiyear personal and professional sabbatical to explore the relationship between childhood trauma, disease, and the processes of healing. He is developing a clinical practice for patients with complex trauma, as well as for others going through significant life transitions. He is working on a book distilling the insights from his sabbatical, teaching, and leading retreats on trauma, integrative health, mindfulness, and well-being for health professionals, students, and the community.
Previously, Dr. Laube was an assistant clinical professor at the UCLA Health Center for East-West Medicine and the David Geffen School of Medicine at UCLA, where he provided primary care and integrative East-West medical consultations. As part of the faculty, he completed a medical education fellowship and received a certificate in innovation in curriculum design and evaluation. He was the fellowship director at the Center for East-West Medicine and led courses for physician fellows, residents, and medical students.
Moira Lawler is a journalist who has spent more than a decade covering a range of health and lifestyle topics, including women's health, nutrition, fitness, mental health, and travel. She received a bachelor's degree from Northwestern University’s Medill School of Journalism and lives in the Chicago suburbs with her husband, two young children, and a giant brown labradoodle.
