Inositol for PCOS, or polycystic ovary syndrome, is one of the best known natural remedies for this condition. Things get a little dicey though when you’re trying to choose a type of inositol and find the right protocol to help your body. Let’s review what inositol is, what it does and what is the best form or forms for you to take to help you the most.
What is Inositol?
Inositol is a naturally-occurring nutrient found in many plant-based foods like oranges and cantaloupe. It used to be considered a vitamin (vitamin B8 to be precise), but an essential component to a nutrient having “vitamin” status is the human inability to produce it ourselves. When it was discovered that inositol can actually be made in the human body from glucose, it was reclassified. The bulk of inositol from foods is called myo-inositol. There are many other forms that are significant for health, and they do different things but the other one that is important for PCOS is D-chiro-inositol. In a completely-unrelated-to-health-but-kind-of-fun aside, inositol is also widely used in explosives (!!) and as a substitute for actual cocaine in TV and movies when they need to show someone snorting something up their nose (!!!)
Why Would You Take Inositol for PCOS?
One of the main issues that face women with PCOS is the strong tendency towards insulin resistance or even outright diabetes. According to a 2017 study from the Journal Gynecological Endocrinology, Inositol, at a dose of 4 g (or 4,000 mg) per day has been shown to be as effective at sensitizing the body to insulin as the drug Metformin. This means that by taking inositol you are helping your body to utilize sugars more effectively and so it helps you to lose some of the insulin-related weight and even to normalize your menses. Inositol is also well known in helping with egg quality and so helps to improve fertility. Inositol also improves ovarian function, reduces testosterone and helps to balance the LH/FSH ratios that are so important for normal ovulation. There are many studies showing all of this, but the best I’ve seen to date is this 2016 review from the International Journal of Endocrinology which compares the effects of myo-inositol and D-chiro-inositol for PCOS. If the label just says “inositol” it’s myo-inositol.
What Does Myo-Inositol do for PCOS?
Myo-inositol is the form that is most commonly naturally occurring and the form that is most commonly suggested for PCOS. Here’s why according to the awesome review from the International Journal of Endocrinology above:
- 4g per day is as effective as the pharmaceutical drug Metformin 1500 mg per day in improving insulin sensitivity (see the reference above for the research).
- With improved insulin sensitivity come improved BMI – this means weight loss
- Menstrual cycle normalizes with 4 g per day dose in about 50% of the women who take it – that is huge because typically women’s hormones are much trickier than that.
- Helps to reduce LH and improve LH/FSH ratios which is important for creating healthy eggs and also for healthy ovulation.
- Myo-inositol helps to reduce total and free testosterone, which is important if you don’t want to be the bearded lady (sadly it doesn’t seem to reduce the hair growth that has already happened. That’s what lasers are for.)
- Helps balance blood lipids by reducing plasma triglycerides and total cholesterol.
- Improves ovarian function. Woot woot!
What does D-Chiro-Inositol or DCI Do for PCOS?
D-chiro-inositol or DCI is being studied more recently for its effects on insulin-mediated androgen synthesis (this means excessive testosterone production secondary to high blood sugars). Normally we are supposed to convert myo-inositol to DCI, but some people don’t do this very well (and many of those people have PCOS). The suggested dose is 600 mg for women 130 lbs or under, 600 mg twice per day for women who are over 130 pounds.
- Improves insulin sensitivity through a different pathway than myo-inositol (by using an IPG mediator).
- Reduces total and free testosterone through the same mechanism myo-inositol does.
- Helps those women who can’t convert myo-inostiol to DCI
- Especially helpful for PCOS if you’re overweight. Not as much if you’re the “skinny” type of PCOS
- DCI is less effective for women with thyroid disease.
What if I Take Both Types of Inositol for PCOS?
Actually, research is showing this is the best course of action in comparison studies. It’s essentially the most effective scenario because the types of inositol complement each other and you don’t have to rely on your body being able to convert anything. Studies show:
- The combination of the two inositol for PCOS gets the same or better blood sugar control, far faster (meaningful change in only 12 weeks for the combo).
- Restores ovulation
- Reduces fasting insulin and fasting glucose
- Decreases LH
- Decreases free testosterone
- Increases Estradiol
- Increases Sex Hormone Binding Globulin (which further reduces the negative effects of testosterone).
So, inositol for PCOS? That’s a big YES. Given the effects on ovaries and egg quality (as well as sperm quality for the men) it’s becoming commonly used in fertility treatments too, whether you’ve got PCOS or not.