I have seen some pretty miraculous results using inositol with women in my practice (it has benefits for men too!). This impressive nutrient can benefit hormones, fertility, thyroid, mood, and insulin regulation. Let’s talk about inositol’s many benefits and how to use it as a supplement.
What is Inositol?
Inositol is actually a type of sugar found naturally occurring in citrus fruit, organ meats, beans, and fiber-rich foods. It’s closely related to the B vitamins and was once called vitamin B8. Although it is synthesized in the body, some individuals may not be able to meet their body’s metabolic needs through its own synthesis alone. (source) People can be deficient due to their diet, poor nutrient absorption (common in Hashimoto’s), or even a genetic predisposition (such as having poor glucose metabolism). And in some cases, like the metabolic and thyroid disorders discussed here, one needs higher doses of inositol than synthesized or available via food sources.
In short, inositol makes your cells more responsive to signals, which can positively impact the hormonal messages needed for fertility, insulin, mood, thyroid, and more. It’s a major component of cell membranes.
In supplement form, you’ll most often see it as D-chiro-inositol and myo-inositol, but there are nine forms in all. I most often recommend myo-inositol or a myo- D-chiro combo. Be aware, however, that too much D-chiro-inositol may actually harm egg quality. It should be taken in a ratio of 40:1 myo- to D-chiro if you are including D-chiro. (source)
Inositol Benefits
- Improves egg quality, ovulation, and fertility
- Helps with blood sugar and insulin regulation
- Benefits those with PCOS due to blood sugar balancing effects + may lower androgens (like high DHEA, testosterone)
- May improve mood (anxiety & depression) and panic disorder
- Improves metabolic syndrome (weight gain, high blood sugar, high cholesterol, high blood pressure)
- Lowers thyroid antibodies and TSH in those with Hashimoto’s
Let’s talk about inositol’s major benefits and how I use it in my practice: for PCOS, fertility, and thyroid.
Inositol for PCOS: Polycystic ovarian syndrome (PCOS) is a common hormonal disorder that causes cysts to form on the ovaries. Symptoms include menstrual irregularity, excess hair growth, acne, fertility problems, and weight gain/difficulty losing weight. Women with PCOS often struggle with high blood sugar and insulin levels, which makes weight loss difficult. I see this with almost every PCOS case I work with. These women also typically have high levels of androgenic hormones like testosterone and DHEA. Causes may involve a combination of genetic and environmental factors.
Eggs can’t mature unless there is a high enough level of myo-inositol in the follicular fluid. Women with PCOS have been shown to produce less mature eggs than women without, and this has been linked this to having too little myo-inositol in the follicular fluid, which surrounds the eggs within the ovaries. (source) That’s why supplementation can help!
A main goal in addressing PCOS is to lower androgen levels, blood sugar, and insulin. Inositol treats several abnormalities associated with PCOS, including high blood pressure and elevated levels of blood fats. In addition, elevated testosterone levels (consistent with PCOS-related hormone imbalances) decreased by 73% compared to 0% for those given a placebo. (source) Inositol may also improve fertility and ovulation in women with PCOS.
When treated with myo-inositol at a dose of around 2 grams, women with metabolic syndrome experienced an 11% drop in diastolic blood pressure, a 20% drop in triglycerides, and a 22% increase in “good” high-density lipoprotein (HDL) cholesterol. (source). Inositol is also good for those who have PCOS and gestational diabetes.
For Hypothyroid: Most hypothyroid cases are caused by an autoimmune attack on the thyroid (Hashimoto’s), and inositol can greatly benefit these folks. I’ve seen a lot of improvement with women (including myself!) using inositol to lower thyroid antibodies, improve thyroid hormone balance, and help regulate blood sugar levels. In addition to lowering antibodies (high TPO antibodies indicate more inflammation and attack on thyroid tissue, so this is one way in which inositol improves thyroid function), research indicates inositol may also ease anxiety and OCD symptoms which also accompany Hashimoto’s. (source)
Inositol also helps manage blood sugar levels, as we’ve seen, and that’s a common issue with hypothyroid/Hashimoto’s. Overall it helps thyroid hormone signaling and benefits these folks all around. Best taken with selenium, which also greatly benefits thyroid and also helps to lower antibodies. I recommend this thyroid support to use with inositol.
For Fertility: Inositol does have antioxidant properties and may improve egg quality, ovulation, cycle regularity, and fertility, BUT some research indicates those without PCOS may not benefit as much from using inositol for fertility. Interestingly, people undergoing in vitro fertilization (IVF) may also see great benefit.
Adding inositol as part of an IVF protocol may improve results. Some studies show that women given myo-inositol had higher rates of retrievable eggs with a reduced need for treatment with FSH to stimulate egg production. A meta-analysis also concluded that It helped induce ovulation for people undergoing IVF.
I always recommend inositol for fertility concerns in those with PCOS. If you’re undergoing IVF, you should add it in.
How to Use Inositol
If you struggle with the above conditions, especially PCOS and Hashimoto’s, you’re a good candidate for inositol. I usually recommend myo-inositol, because taking too much d-chiro can lower estrogen levels and increase male hormone levels. If you do take a myo- d-chiro inositol, make sure the ratio is 40:1.
For PCOS and metabolic syndrome, you can use up to 2 grams twice daily. I recommend this formula which also contains alpha-lipoic acid for increased blood sugar support. The dose is 2 caps twice daily, preferably empty stomach.
For thyroid, you need 700-900mg daily. For that I recommend this myo-inositol, and all you need Is 1 cap! I recommend taking it before bed as it may also support sleep. You can also use this powder formula if you prefer. 1 scoop is 700mg.
Remember that quality supplements matter! I only use a few select companies whom I trust due to their rigorous quality control. All the supplements I recommend have been vetted by me and third party tested.
If you do not have any of the above conditions, you probably won’t benefits much from inositol. And as mentioned, women without PCOS or metabolic disorders may not reap any fertility benefit from inositol.
Contraindications
Inositol is generally considered very safe and without side effects in most people. But I’ve read people with kidney disease/kidney issues should not take it. Do not take it if you are pregnant or breastfeeding.
While research has shown that myo-inositol seems to have a normalizing effect on testosterone in women with PCOS, myo-inositol has been shown to increase testosterone in men with low levels of this hormone. Thus, myo-inositol can be used by both men and women. (source)
Make sure you test your hormones about 4-6 weeks into taking inositol so you can determine how it’s working for you and if you need to adjust your dosage. You can test your thyroid hormones at home here (get the thyroid test), or test female hormones (estrogen, progesterone, testosterone), DHEA, thyroid, and cortisol with the Women’s Health Test. (use the link to enter then search for the test).
Conclusion
There’s good research that inositol greatly benefits those with PCOS due to its blood sugar balancing and hormone regulating properties. It’s also excellent for those with elevated thyroid antibodies or higher TSH levels.
Side note: A woman with whom I worked who has Hashimoto’s began inositol and saw incredible improvements in TPO antibodies, which dropped from 175 into normal range, AND she saw a boost in T3 and a lower TSH. Perhaps the best part is that she reported her menstrual cramps disappeared after starting inositol (perhaps because of such great thyroid improvements). Love hearing those stories.
Inositol is great for metabolic syndrome, mental health, sleep, and fertility, especially in those undergoing IVF. It’s safe in doses up to 18 grams, but the most I recommend is 4-6 grams daily in those with PCOS.
I have seen some amazing benefits in women taking inositol, so it is worth a try if you struggle with these conditions. Remember to test your hormones to see how it’s working for you.
And men, it may help improve your sperm quality and testosterone levels!
Mary Vance is a Certified Nutrition Consultant and author specializing in digestive health. She combines a science-based approach with natural therapies to rebalance the body. In addition to her 1:1 coaching, she offers courses to help you heal your gut and improve your health. Mary lives in San Francisco and Lake Tahoe in Northern California. Read more about her coaching practice here and her background here.
