Inositol
OTHER NAME(S): inositol, D-chiro-inositol, inositol hexaphosphate (IP6), myo-inositol, phytate, phytic acid, vitamin B8
Overview
Inositol is found in foods, and it is also available over the counter as a supplement. There are many forms of inositol available, including inositol hexaphosphate (IP6), myo-inositol, and D-chiro-inositol. These products are used for various reasons, although their benefits are not well defined. A common side effect is an upset stomach. Before taking inositol, tell your health care provider about all of your health conditions and any medicines or supplements you may be using.
Uses
What is inositol used for?
Various forms of inositol have been used for different reasons. However, their benefits are not well defined. Some common reasons for using inositol products include the following.
- Gestational diabetes
- Polycystic ovary syndrome (PCOS)
- To reduce the side effects from chemotherapy
- Weight loss
These uses may vary depending on the specific product you are using.
Inositol may also be used for other conditions as determined by your health care provider.
Note: The FDA has not reviewed inositol for safety and effectiveness. Learn more about dietary supplements here.
How does inositol work (mechanism of action)?
Inositol is a chemical that is naturally found in your cells. Your body makes inositol on its own, but you can also get it from fruits, vegetables, grains, rice, beans, and meat. Your body uses inositol to maintain the functions inside your cells and send messages between cells. Although inositol is sometimes called vitamin B8, it is not actually a vitamin.
There are many forms of inositol that are naturally found in your body, including inositol hexaphosphate (IP6), myo-inositol, and D-chiro-inositol. Most over-the-counter supplements that contain inositol have one of these three forms. However, each of these forms has been studied for different uses.
IP6, which is also known as phytic acid or phytate, has mostly been studied for reducing side effects from chemotherapy. Although some studies suggest that it may help reduce side effects from certain chemotherapy medicines, its benefits are not well defined. It is not clear who may benefit from taking IP6 during chemotherapy.
Myo-inositol and D-chiro-inositol have mostly been studied in people with a condition called polycystic ovary syndrome (PCOS). If you have PCOS, your body may not respond to insulin as well as it should (insulin resistance). You may also have problems with other hormone levels in your body. Myo-inositol and D-chiro-inositol may help improve your body’s response to insulin. The amount of these substances in your body may also affect your hormone levels. Although some research has found small benefits with these supplements, other research has found no benefits. It is still not clear if these supplements can help with PCOS.
During pregnancy, some people have insulin resistance due to the hormonal changes in their bodies. In some cases, this can lead to a condition called gestational diabetes. There is interest in using myo-inositol and D-chiro-inositol to prevent gestational diabetes, but their effects are unclear. While some research has found small benefits, other research has shown no benefits. Also, in people with PCOS, taking myo-inositol does not seem to help prevent gestational diabetes.
Although there is also interest in using myo-inositol or D-chiro-inositol to help with weight loss, their benefits for this use are not well defined.
How should I store inositol?
You should store inositol 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 inositol?
The most common side effect of inositol is an upset stomach. 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 side effects that bother you.
There may be other side effects of inositol 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 inositol?
While less common, the most serious side effects of inositol are described below, along with what to do if they happen.
Severe Allergic Reactions. Inositol may cause allergic reactions, which can be serious. Stop taking inositol 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
Precautions
Who should not use inositol?
Allergies to Ingredients. People who are allergic to any of the following should not take inositol.
- D-chiro-inositol
- Inositol
- Inositol hexaphosphate (IP6)
- Myo-inositol
- Vitamin B8
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific inositol products they stock.
What should I know about inositol before using it?
Inositol is a dietary supplement. It cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are taking, or take it as recommended by your health care provider.
Keep inositol out of the reach of children.
Dietary supplements may contain many forms of inositol, including inositol hexaphosphate (IP6 or phytate), myo-inositol, and D-chiro-inositol. Each of these forms of inositol have been studied in different ways. Read the product label carefully to check which form it contains.
Inositol should be taken on an empty stomach with a full glass of water. Avoid taking inositol within about two hours before or after a meal. See the Interactions section for more details.
If you are using inositol powder, use an appropriate measuring device to measure the powder, such as the device included with the product. Read the label carefully, and measure the amount stated on the label.
The FDA has not tested inositol 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 inositol?
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 inositol is right for you.
In particular, make sure that you discuss any of the following.
Other Medicines and Supplements.Inositol may interact with other medicines and supplements. Before taking inositol, 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 inositol 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 inositol passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does inositol interact with foods or drinks?
Avoid taking inositol within about two hours before or after eating food. Inositol may bind to important minerals in your food, such as calcium, iron, magnesium, or zinc, and prevent your body from absorbing them.
It is unknown if drinking alcohol will affect inositol.
Does inositol 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 inositol.
- A medicine for diabetes
- A supplement that contains calcium, iron, magnesium, or zinc
The interactions between inositol and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with inositol is incomplete. Always check with your health care provider before taking inositol with any medicines.
Dosing
What should I do if I accidentally use too much inositol?
If you or someone else has used too much inositol, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Inositol dietary supplements contain many doses and forms of inositol. Read the product label closely, and speak with a health care provider about how to take inositol safely. Do not take double or extra doses, even if you miss a dose.
References
- Biomedicines: “The biomedical uses of inositols: a nutraceutical approach to metabolic dysfunction in aging and neurodegenerative diseases.”
- JAMA: “Myo-inositol supplementation to prevent pregnancy complications in polycystic ovary syndrome: a randomized clinical trial.”
- Memorial Sloan Kettering Cancer Center: “Inositol Hexaphosphate.”
- National Cancer Institute: “inosito - NCI Dictionary of Cancer Terms,” “inositol - NCI Drug Dictionary.”
- Nutrients: “Inositol nutritional supplementation for the prevention of gestational diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.”
- Obesity Science & Practice: “Inositol supplementation and body mass index: A systematic review and meta-analysis of randomized clinical trials.”
- The Journal of Clinical Endocrinology and Metabolism: “Inositol for polycystic ovary syndrome: a systematic review and meta-analysis to inform the 2023 update of the international evidence-based pcos guidelines.”