Overview

Beta-hydroxybutyrate (BHB) is a chemical found in your body that is also available over the counter as a dietary supplement. Your body makes BHB when it turns fat into energy (a process called ketosis). As a result, some BHB supplements are called “keto supplements.” But the benefits of taking BHB supplements for any use are not well defined. Common side effects include bloating, gas, acid reflux, nausea, vomiting, and upset stomach. Before taking BHB, make sure to tell your health care provider about any health conditions you have or medicines you are taking.

Uses

What is beta-hydroxybutyrate (BHB) used for?

BHB is used for various reasons, although its benefits are not well defined. Some common reasons for using BHB include the following.

• Diabetes
• Weight loss
• To improve athletic performance

BHB may also be used for certain rare metabolic disorders as determined by your health care provider.

Note: The FDA has not reviewed BHB for safety and effectiveness. Learn more about dietary supplements here.

How does BHB work (mechanism of action)?

Your body usually uses sugar (carbohydrates) as a source of energy. But it is also able to use fat as a source of energy, especially at times when there is not enough sugar available. Using a process called ketosis, your body turns fat into ketone bodies. Your heart, brain, and other organs are able to use ketone bodies as a source of energy.

Beta-hydroxybutyrate (BHB) is a type of ketone body. It is naturally present in your body at all times, but the levels of BHB increase when your body needs to use fat to make energy. This may happen during a very long workout. It also happens in people who follow a very low carbohydrate diet, such as the ketogenic diet.

High levels of BHB are thought to be related to better metabolic health. These high levels are usually seen in people who follow a very low carbohydrate diet. Taking BHB supplements can increase the levels of BHB in your body. But it is not clear if taking BHB supplements has the same effect as following a very low carbohydrate diet. Some studies show that taking BHB may help lower blood sugar levels by a small amount. But the benefits of BHB for weight loss are not well defined. Although some BHB products claim that they can push your body into ketosis, research on this claim is limited.

Since your heart and muscles can use ketone bodies for energy, there is also interest in taking BHB supplements to improve athletic performance. But there is very little research on using BHB for this reason, and its benefits are unclear.

BHB supplements are also used by some people who have a type of rare metabolic disorder called multiple acyl-CoA dehydrogenase deficiency (MADD). In people with this condition, the body is not able to use fat as a source of energy. Taking BHB supplements can help replace this missing energy and prevent serious symptoms and complications.

How should I store BHB?

You should store BHB according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of BHB?

The most common side effects of BHB are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.

• Acid reflux
• Bloating, burping, or gas
• Nausea or vomiting
• Upset stomach or stomach pain

There may be other side effects of BHB that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of BHB?

While less common, the most serious side effects of BHB are described below, along with what to do if they happen.

Severe Allergic Reactions. BHB may cause allergic reactions, which can be serious. Stop using BHB and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching or skin rash
• Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Diabetic Ketoacidosis(DKA).BHB may increase your risk of a serious, life-threatening condition called diabetic ketoacidosis. This risk may be higher in people who also take certain medicines or follow a very low carbohydrate diet, such as the ketogenic diet. Stop taking BHB and get help right away if you have any of the following symptoms of diabetic ketoacidosis.

• Nausea or vomiting
• Stomach pain
• Feeling very tired, woozy, or confused
• Trouble breathing
• Your breath smells fruity or sweet
• Very high blood sugar levels (over 300 mg/dL)

Precautions

Who should not use BHB?

Allergies to Ingredients. People who are allergic to any of the following should not use BHB.

• 3-hydroxybutyrate
• Beta-hydroxybutyrate (BHB)
• Calcium beta-hydroxybutyrate (Ca-BHB)
• Magnesium beta-hydroxybutyrate (Mg-BHB)
• Sodium beta-hydroxybutyrate (Na-BHB)
• Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific BHB products they stock.

What should I know about BHB before using it?

BHB is a dietary supplement. It may also be found in some foods and drinks. It cannot be marketed to treat or cure a disease.

Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.

Keep BHB out of the reach of children.

BHB may be added to dietary supplements that are marketed as “keto supplements.” These supplements may include many ingredients that have different effects in the body. Read the product label closely to see which ingredients it contains.

Dietary supplements may contain many forms of BHB, including calcium-BHB, magnesium-BHB, and sodium-BHB. It is not clear if any of these forms of BHB work differently in the body. Sodium-BHB may contain high amounts of sodium (salt). If you are sensitive to salt or follow a low-salt diet, talk to your health care provider before taking a product that contains sodium-BHB.

The FDA has not tested BHB products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.

What should I tell my health care provider before using BHB?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if BHB is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions.Tell your health care provider if you have any of the following.

• Diabetes
• Kidney problems
• Follow a very low carbohydrate diet, such as the ketogenic diet

Other Medicines and Supplements.BHB may interact with other medicines and supplements. Before taking BHB, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how BHB could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if BHB passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does BHB interact with foods or drinks?

There are no known interactions between BHB and foods or drinks.

It is unknown if drinking alcohol will affect BHB. But drinking large amounts of alcohol may increase your risk of a serious condition called diabetic ketoacidosis. See the Side Effects section for more details. It is best to limit the amount of alcohol you drink.

Does BHB interact with medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking BHB.

• A medicine for diabetes
• An SGLT2 inhibitor, such as canagliflozin (Invokana), dapagliflozin (Farxiga), or empagliflozin (Jardiance), which is a medicine that may be used for diabetes or for certain heart or kidney problems

The interactions between BHB and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with BHB is incomplete. Always check with your health care provider before taking BHB with any medicines.

Dosing

What should I do if I accidentally use too much BHB?

If you or someone else has used too much BHB, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Read the product label closely, and speak with a health care provider about how to take BHB safely. Do not take double or extra doses, even if you miss a dose.