Inositol: Health Benefits and Side Effects

Medically Reviewed by Zilpah Sheikh, MD on April 13, 2024
5 min read

Inositol, also called myo-inositol, D-chiro-inositol, or hexaphosphate (IP6), plays a critical role in the body’s cellular growth. Though it used to be referred to as Vitamin B8, inositol is not actually a vitamin. It’s a type of sugar that helps your body process insulin.

Inositol used to be thought of as an essential nutrient, which is any nutrient that must be obtained from your diet. However, observations have shown that the liver and kidneys make inositol from glucose, so it’s not an essential nutrient.

In addition to being produced by your body, inositol is also found in a wide range of healthy foods. Though inositol is a sugar that your body produces from glucose, diets high in sugar can inhibit inositol availability.

Inositol is essential for several different cellular processes. It acts as a messenger for your cells and helps with functions such as regulating insulin and binding neurotransmitters.

Additionally, inositol may provide health benefits:

Improved metabolic syndrome

Metabolic syndrome includes several risk factors such as high blood pressure, belly fat, and high blood sugar, which all increase the risk for diabetes and heart disease. In one study, women who were postmenopausal and had metabolic syndrome took inositol supplements for 1 year. At the end of the year, they all showed improvement in their metabolic syndrome. In fact, 20% of the women no longer met the criteria for having metabolic syndrome.

Reduced chance of gestational diabetes

Gestational diabetes is a type of diabetes that occurs only during pregnancy. In one study, women at high risk for gestational diabetes were treated with inositol and compared with a group of women who were given a placebo. The women treated with inositol were less likely to develop gestational diabetes and require insulin.

Inositol and PCOS

When you have Polycystic ovarian syndrome (PCOS), you have increased insulin resistance, which has side effects such as increased body mass index (BMI) and abnormal menstrual cycles. Inositol was as effective as metformin, a medicine that is commonly used to treat type 2 diabetes, in increasing insulin sensitivity in women with PCOS. About half of the women showed a decrease in BMI, and their menstrual cycles returned to normal.

Lower blood sugar levels

A type of inositol, D-chiro-inositol, combined with folic acid also increased insulin sensitivity in people with type 1 diabetes. People treated with inositol and folic acid had lower average blood sugar levels, known as HbA1c, than the people in the control group.

Inositol for anxiety

People with panic disorder reported fewer panic attacks while taking inositol than they did with fluvoxamine, an antidepressant often used to treat anxiety disorders. Negative side effects such as nausea and tiredness occurred less often with inositol than with fluvoxamine. Because it’s a natural supplement, people who are hesitant to take psychiatric drugs such as antidepressants may be more willing to take inositol.

Improved psoriasis in people taking lithium

Lithium carbonate is widely prescribed for people with bipolar affective disorders. Unfortunately, one of the side effects of lithium can be psoriasis, a skin condition. People with psoriasis who were taking lithium showed an improvement in their psoriasis after using inositol supplements. However, inositol failed to improve psoriasis in people who were not taking lithium.

Inositol benefits for hair

Inositol has been touted as a substance that might boost hair growth, reduce frizziness, and produce healthier hair. Inositol can be found in rice bran, and some social media sites suggest treating your hair with rice water, which is made by soaking rice in water for 30 minutes. Treating hair with rice water has been a custom in parts of Asia for centuries. Some research suggests that inositol may encourage hair growth, but more study is needed. Rice water is unlikely to harm you unless you have a skin condition such as eczema or dermatitis. If you have significant hair loss — called alopecia — you should consult a doctor before trying home remedies.

Inositol and sleep

Scientists are looking at whether this supplement can improve your sleep. One small study of pregnant women found that inositol supplements led to better sleep.

Inositol vs. metformin

A review of several studies found that inositol was safe and effective in treating PCOS compared to the diabetes drug metformin, which can cause digestive issues in some people.

Because inositol is water-soluble, it doesn't have a high risk of overdose. It's considered safe when you take it in low doses for up to 10 weeks.

Inositol might cause mild side effects, such as:

  • Diarrhea
  • Nausea
  • Stomach pain
  • Feeling tired
  • Headache
  • Dizziness

Inositol is a dietary supplement, and the FDA doesn't regulate them the same way they do drugs. There is no recommended daily allowance (RDA) for inositol or recommended dose.

Inositol supplements can carry different names:

  • Myo-inositol
  • D-chiro-inositol
  • Inositol hexaphosphate

Most studies use 10-18 grams per day of inositol to achieve desired results with minimal to no side effects.

Your body produces a certain amount of inositol every day in your liver and kidneys.

Inositol-rich foods

Inositol can be found in meat, fruits, vegetables, grains, and beans. Specific foods that contain inositol include:

  • Blueberries
  • Lettuce
  • Garlic
  • Kale
  • Mint
  • Carrots
  • Chicory
  • Endive
  • Escarole
  • Artichokes
  • Spinach
  • Beetroots
  • Radishes
  • Cabbage
  • Onions
  • Black-eyed peas
  • Buckwheat
  • Chickpeas
  • Lentils
  • Honey

Inositol is a type of sugar found naturally in your body and in certain foods. It's also available as a supplement. Your body uses it to form cells, and it may play a role in how you process insulin. Scientists have studied it as a treatment for several conditions, including PCOS, gestational diabetes, metabolic syndrome, and a variety of mental health disorders. There is some research to suggest inositol might help with these conditions, but the evidence isn't clear. Taken in low doses, inositol is unlikely to have serious side effects. But some people do have digestive trouble, headaches, and dizziness.

What does inositol do to your body?

Your body needs inositol for your cells to develop and function. It also works as a chemical messenger in your body.

Is it safe to take inositol every day?

Because inositol is a dietary supplement, the FDA doesn't regulate it the same way it does drugs. There's no recommended dose. It's generally considered safe when you take a low dose for 10 weeks.

What does inositol do for the brain?

Some studies suggest it helps balance certain substances in your brain, including serotonin and dopamine. But more research is needed.

What foods are high in inositol? 

You can get inositol from meats, fruits, vegetables, beans, and grains. Blueberries and chickpeas are two foods with higher levels of inositol.