Metformin vs. Inositol (Ovasitol/Ovacure) for PCOS

What is Metformin?

Metformin is the active ingredient in drugs that go by brand names such as Bolamyn, Diagemet, Glucient, Glucophage and Metabet. Liquid metformin is called by the brand name Romet.

In the beginning of the twentieth century, scientists in Europe first discovered that a substance called guanidine, which is extracted from a plant called goat’s rue, could lower blood sugar levels. Some derivatives of guanidine were synthetized and temporarily used, but because of side effects and the availability of insulin, taken off the market.

Metformin is one of those derivatives, but it was not used at the time. Its popularity started in the year 1995 when it was introduced in the USA. (1) It has been on the market ever since and is a common drug being used to lower glucose levels in diabetes type 2 patients and often prescribed to women with PCOS struggling with insulin resistance, a main underlying root cause driving the disease.

Click here to learn more about insulin resistance.

How Does Metformin Work?

Metformin influences blood sugar levels in two ways: It reduces the amount of sugar released by the liver and supports the cells to respond better to the hormone insulin, so the sugar from the blood stream can enter the cells more easily. (2) This is a mechanism often malfunctioning in women with PCOS due to insulin resistance.

Since high levels of blood glucose and insulin drive PCOS symptoms such as weight gain, high testosterone and missing periods – due to a lack of ovulation, taking metformin can be beneficial, since it lowers glucose, as well as insulin levels and thus supports weight loss and ovulation.

Possible Side Effects of Metformin

Unfortunately, Metformin is a synthetic drug and it is very common to experience gastrointestinal side effects such a nausea, diarrhea or loss of appetite. Too much of this drug can also lead to hypoglycemia – very low blood sugar levels.

Metformin is a prescription drug and should be taken with the supervision of a doctor only.

Now let’s move on and have a closer look at inositol.

Metformin vs. Inositol 

What is Inositol?

There are about 9 different inositols occurring naturally inside our bodies and in food. They belong to the family of sugar alcohols. Among all inositols, myo-inositol (MI) and d-chiro-inositol (DCI) are the most abundant members. Popular PCOS supplements containing inositol are Ovasitol and Ovacure.

How Does Inositol Work?

MI produces second messengers that increase the ovaries’ sensitivity to FSH (Follicle Stimulating Hormone – often low in women with PCOS), which can support maturation of egg follicles and improve chances of ovulation. Both, MI and DCI increase the cells’ sensitivity to insulin and thus promote glucose uptake. DCI also support the liver in the production of glycogen, a molecule that is build from excess sugar in the blood stream. (3)

Similar to metformin, inositol lowers insulin levels and thus helps decrease symptoms associated with elevated testosterone, such as acne, anovulation and weight gain, for example.

What are Possible Side Effects of Inositol?

Since MI and DCI are components naturally occurring in the body, taking a supplement far subceeds the side effects associated with Metformin. Some mild side effects may include nausea, stomach pain, tiredness, headache, and dizziness (4). Supplements containing inositol such as Ovasitol or Ovacure don’t need a prescription, but it is always recommended to take supplements with the recommendation and supervision of licensed physician.

Have you tried Metformin or inositol before? What was your experience. Please share with us in the comments below.

Sending you my love,



  1. Bailey CJ. Metformin: historical overview. Diabetologia. 2017 Sep;60(9):1566-1576. doi: 10.1007/s00125-017-4318-z. Epub 2017 Aug 3. PMID: 28776081.
  2. https://www.nhs.uk/medicines/metformin/
  3. Bizzarri M, Carlomagno G. Inositol: history of an effective therapy for Polycystic Ovary Syndrome. Eur Rev Med Pharmacol Sci. 2014 Jul;18(13):1896-903. PMID: 25010620.
  4. https://www.verywellmind.com/inositol-what-should-i-know-about-it-89466

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Nadine is a PCOS health coach, hormone expert, and woman with PCOS who helps other cysters around the world manage their symptoms naturally, lose weight and increase fertility.