Do Keto Diet Pills Work, and How Do They Help You Lose Weight?

If you’ve been trying to lose weight at any point over the past several years, chances are you’ve heard about, or possibly even tried, a ketogenic diet. This fat-heavy approach to weight loss has gained a lot of attention in recent years, but it’s not the easiest diet to get quite right.


Originally developed in the 1920s to help children with difficult-to-control epilepsy, the ketogenic, or keto, diet eliminates nearly all carbohydrates. This means your body has to rely on other means of fuel, such as fat and protein.

The classic keto diet “is a high-fat, adequate-protein, low-carbohydrate diet designed to produce ketosis through mimicking the metabolic changes of starvation, forcing the body to use fat as its primary source of energy,” explains Cathy Leman, a dietitian, personal trainer, nutrition therapist and breast cancer survivor based in Chicago. Leman is also the founder and creator of the Peaceful Plate program.

Truly following a classic keto diet means you’ll be taking in 90% of your daily calories from fat. Your protein level should stay below 6% of total calories, and carbohydrates should be kept at 4% of daily calories.

[See: The Best Low-Carb Vegetables]

Helping the Body Achieve Ketosis

Hitting those ratios is important to make the keto diet work. When the body relies on fat for fuel, it generates ketone bodies, which are chemicals manufactured in the liver when fat is broken down and turned into energy. This process is called ketosis. If you have excess fat in your body, it stands to reason that you should be able to burn that as fuel to help you lose weight, which is why the keto diet is popular.

However, getting into and staying in ketosis can be tricky because it requires consistently consuming that exact ratio of carbs to fats to proteins. Emilie Vandenberg, a registered dietitian at the Ohio State University Wexner Medical Center in Columbus, explains that although the ketogenic diet is often thought of as a low-carb, high-protein diet, eating too much protein can prevent you from entering or maintaining ketosis.

That’s where certain substances called exogenous ketogenic supplements — aka keto diet pills — might come into play.

The human body generates ketone bodies naturally — or endogenously in med-speak — when it breaks down fat for fuel. But you can also introduce ketone bodies from an exogenous — or external — source, such as an exogenous ketogenic supplement.

Essentially, exogenous ketogenic supplements are a pill or powder that contains ketone bodies. These supplements are intended to boost the levels of ketone bodies as a whole in the human body to facilitate ketosis. The idea is that by supplementing exogenous ketones, you may not have to actually eat a keto diet at all to reap the benefits.

Erin Holley, a registered dietitian at the Ohio State University Wexner Medical Center, says, “In theory, taking extra ketones in the diet may help the body lose weight by using ketones for energy and therefore burning fat. The claim is that you can take these keto diet pills and not have to follow a low-carb diet.”

Such supplements are also marketed to help dampen symptoms of the so-called “keto flu,” says Gaby Vaca-Flores, a registered dietitian and founder of Glow+Greens, a nutrition and skin care consultancy based in Santa Monica, California. Keto flu tends to develop within about a week of adopting a ketogenic diet and includes a range of unpleasant symptoms, including:


Brain fog.

— Fatigue.

— Irritability.

— Nausea.


— Sleep changes.

It’s not clear what exactly causes keto flu, and it’s not an accepted medical term, but the phenomenon can be uncomfortable for those switching to a keto diet. The symptoms typically resolve within a few days as your body adjusts. Vaca-Flores notes, “There’s no evidence suggesting that keto pills can help prevent ‘keto flu’ symptoms.” So, those claims may be just that: claims.

[Read: Keto-Friendly Sweeteners.]

Types of Keto Diet Supplements

There are a number of different products marketed as exogenous ketogenic supplements. They usually contain the active ingredient beta-hydroxybutyrate ketone, and many also contain MCT oil, a type of fat found in coconut and palm oil, that is combined with salt and potassium.

The two most common types of keto diet pills are:

Ketone esters, which are usually sold as a liquid and are used more often in research settings rather than in consumer products.

Ketone salts, which are often sold as a powder that’s made by combining ketones with other chemicals, such as potassium, magnesium, sodium or calcium.

Holley notes that most keto diet supplements are “loaded with sodium, so if you have high blood pressure or are particularly sensitive to salt, I would not take these.”

Do Keto Pills Work?

The idea is that these supplements can assist you in getting into ketosis faster; it typically takes from about two days to more than a week to reach that fat-burning state. And once you’re in ketosis, a supplement could help you stay there. Theoretically, this all means you might lose more weight even faster.

The theory makes sense. If you need ketone bodies to achieve ketosis, adding them as a supplement should help. But whether exogenous ketogenic supplements actually work isn’t entirely clear.

Some research, such as this 2020 study, suggests that taking exogenous ketones can help boost concentrations of ketones in the blood quickly. “However, it’s still unclear as to whether exogenous ketones will produce the same type of ketosis effects as diet,” Vaca-Flores says.

And whether supplements can help you achieve ketosis faster or maintain it longer than dietary shifts is still inconclusive, according to a 2018 review study. “In other words, keto diet pills may not help you lose weight in the same way that a keto diet would,” Vaca-Flores explains.

One of the reasons why supplementation may not be all that effective is because the body seeks to maintain an even level of ketones to prevent a potentially toxic buildup of these chemicals in the bloodstream. When the body senses that ketone levels are high, the liver stops making its own, so supplementing ketones might actually cause your body to stop producing them. This could in turn actually limit your ability to stay in that target ketogenic, fat-burning zone that’s been associated with rapid weight loss.

[READ: Does Keto Cause Menopause?]

Weaknesses of the Keto Diet

While there’s some indication that the keto diet

itself is effective for weight loss, there’s little in the way of long-term research as to how it impacts the body, whether the weight loss you might achieve is durable and whether it’s any better than a conventional low-fat diet.

That’s according to a recent NIH study in the journal Nature Medicine, which compared calorie intake on a low-fat diet versus a ketogenic diet. The analysis found that during a two-week intervention, the low-fat diet eaters consumed about 700 fewer calories per day and lost about a pound more of fat than the keto group. The keto group lost more mass, but it wasn’t from fat and was instead mostly water, which is often what is lost first on a keto diet. Whether those effects would shift had the study continued longer is not clear and is an area of active investigation.

There is some evidence that following the ketogenic diet can decrease levels of ghrelin, one of your body’s main hunger hormones, which may make it easier to avoid overconsumption of calories. Indeed, feeling more satiated on the keto diet is a key benefit many followers say has helped them lose weight and feel better.

However, significantly reducing carbohydrate intake can lead to water loss, because carbs hold water when stored in your body. When you lower your carb intake, stored carbs and additional fluid are released. This is what causes the rapid weight loss that’s associated with switching to a keto diet. This is problematic because when you come off a keto diet, your consumption of carbohydrates will increase. This means your body will hang onto more water and some of that weight loss will be reversed in short order.

For many people, maintaining a keto lifestyle is difficult because a high-fat, adequate-protein and low-carb diet can be restrictive. It’s common to come off the diet and regain weight, regardless of whether you’re using a supplement or not.

Check With Your Doctor

If you’re planning to use a keto diet pill or powder, be sure to do your homework first. “(While they’re) probably safe to use for most people, I certainly don’t recommend diet pills for anyone,” Holley says.

In addition, some dietitians don’t recommend following the keto diet at all, whether you’re adding a pill or not.

Dana Ellis Hunnes, a senior clinical dietitian at UCLA Medical Center, assistant professor at UCLA Fielding School of Public Health and author of “Recipe For Survival,” says the keto diet has some health risks for “cardiovascular health, the gastrointestinal tract and microbiome, with an increased risk for colorectal cancer and possible hypoglycemia (low blood sugar) and low energy.”

In other words, the keto diet isn’t entirely risk-free, and it isn’t for everyone. You should talk to your doctor and a dietitian before you start it.

Still, if you’re going keto and want to add a supplement for weight loss — or any other reason — be sure to speak with your doctor first. There’s always the possibility that a nutritional supplement will interact negatively with another medication you’re taking or cause other unintended side effects. Be sure to discuss everything that you take, whether it’s a prescription or an over-the-counter medication, with your health care provider.

Ask your physician to check your blood work to ensure an extremely low-carbohydrate diet is an appropriate option for you. And keep in touch with your doctor to ensure that you’re staying healthy while following the plan. Your doctor should check your bloodwork regularly to keep an eye on blood glucose levels and to make sure that your liver and kidney function remains stable.

Ketosis can result in low blood sugar, fatty liver, nutrient deficiencies and altered fat metabolism,” Vaca-Flores explains. “Due to these risks, individuals with certain health conditions involving organs like the liver, pancreas, gallbladder or thyroid should avoid trying the keto diet or keto pills without first consulting their physician.”

Buyer Beware

Keto diet pills can be “really expensive,” and there’s not enough evidence to justify that cost, Holley says. Some companies may enroll you in an autorenewal plan where you automatically get charged for a new shipment of pills each month without your realizing it. These plans can be difficult to cancel and may be costlier than expected.

Dietary supplement products are also not regulated by the Food and Drug Administration, so it can be difficult to know whether you’re getting what you pay for. Ask the company to provide its research or evidence that the supplement does what the company is saying it does. A reputable manufacturer should be able to provide information about how its product has been tested and what it contains.

“Since there is limited research comparing different keto pills, it’s difficult to develop criteria for choosing the best one,” Vaca-Flores notes. “As a rule of thumb, it’s best to choose a supplement brand that makes their product at a manufacturer that has Good Manufacturing Practices (or GMP) certification. This will help ensure that third-party testing of the product is taking place.”

There’s an additional risk of scams with some of these products. Specifically, be wary of supplements being pushed heavily on social media. In July 2020, AARP reported that two women in their 80s had been scammed out of more than $200 each when they purchased keto diet pills. AARP also warned that the number of reported scams is on the rise.

To protect yourself, the FDA is encouraging consumers to be cautious of any supplements being pushed via email or pop-up ads — these points of contact are more likely to lead to a scam product. Also, keep an eye out for warning words and phrases in any marketing text, such as “quick fix,” “guaranteed results” and “scientific breakthrough.” They’re usually a red flag that the product is making claims it’s unlikely to be able to provide.

Alas, there are few shortcuts to healthy and sustainable weight loss, and using a supplement to speed up the process could mean you end up dropping more dollars than pounds. “So far, research isn’t showing that taking extra (exogenous) ketones produces greater weight loss,” Holley summarizes. “In fact, it might actually stop the body from making its own ketones when it suspects there are enough in the blood because you’ve taken them by mouth.”

She adds, “Truly, these are a waste of your money. Do not fall for this gimmick. If you’re thinking about purchasing these, please speak with your doctor or a dietitian first.”

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Do Keto Diet Pills Work, and How Do They Help You Lose Weight? originally appeared on

Update 03/06/23: This story was published at an earlier date and has been updated with new information.

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