Metformin – PCOS Wonder Drug?

Following on from my recent post about the pros and cons of using the supplement inositol to treat PCOS symptoms, I’ve had a number of clients tell me that they’ve heard about the potential benefits of the prescription drug metformin on PCOS symptoms. So today I wanted to dig down to look at both the pros and cons, and answer the question – is Metformin a PCOS wonder drug? Let’s go! 

What exactly is PCOS?

Several of my clients suffer from polycystic ovary syndrome (PCOS), which is currently one of the most common endocrine (ie hormonal) issues experienced by women of reproductive age in both the USA and the UK. Symptoms of PCOS include the following:

• Weight gain
• Irregular periods
• Ovarian cysts
• Acne
• Thinning hair

The causes of PCOS are complicated and not clearly understood yet, although we do know that hormone regulation and particularly insulin resistance are key factors.

My ‘first line’ interventions to improve symptoms of PCOS

We know that lifestyle and dietary interventions can have a significant impact on improving insulin resistance and the symptoms of PCOS. My first line recommendation to clients suffering from PCOS is to switch to a more ‘wholefood-centric’ diet – reducing ultra-processed foods as much as possible which can have a very significant impact, since these foods can harm your friendly gut-bacteria. In particular, ensuring your diet contains sufficient dietary fibre is crucial to improving the symptoms of PCOS. Similarly, introducing frequent bouts of short yet higher intensity forms of exercise can also have a huge benefit.

Metformin and PCOS

So what about the type 2 diabetes drug metformin, can it improve PCOS symptoms? First of all – what exactly is metformin? Well, it’s a drug which is commonly prescribed in the form oral tablets and is used to treat high blood glucose caused by type 2 diabetes. Common brand names include: Axpinet, Diagemet, Glucient, Glucophage, Glumetza and Metabet. Specifically, it works by reducing the amount of glucose produced by your liver, lowering the amount of glucose your body absorbs and increasing the blood-sugar lowering effect of insulin in your body.

Benefits of Metformin for PCOS:

Since Metformin helps to reduce the impact of  insulin resistance it seems logical that Metformin should be able to help improve the symptoms of PCOS, since insulin resistance is a key driver behind PCOS. And this appears to be borne out by the studies: this study from 2015 showed that Metformin plus diet & lifestyle modifications improved the symptoms of PCOS. But crucially it had no effect on its own after 6 months – it needed to be combined with the diet & lifestyle modifications in order to show a significant effect! This study from 2020 showed that metformin in isolation improved certain indicators of PCOS, but not others. And according to the UK NHS website, metformin “causes more ovulation if you have PCOS, and can encourage regular periods even if you do not have diabetes”.

Potential drawbacks of Metformin for PCOS:

Many people experience stomach problems when taking metformin – for example: diarrhoea, stomach cramp, nausea, heartburn, gas. If the effects are mild, they may go away within a few days, but if not, you need to talk to your doctor. More serious but less common side effects include hypoglycaemia (low blood sugar) – with symptoms such as headache, weakness, confusion and drowsiness – and also lowered Vitamin B12 levels – with symptoms such as muscle weakness, loss of energy and lowered appetite. There have also been some cases of ‘lactic acidosis’ – with symptoms including trouble breathing, unusual sleepiness and slowed or irregular heart rate.

So is it worth taking Metformin for PCOS?

The evidence seems to indicate that Metformin can improve some of the symptoms of PCOS – but that it becomes much more powerful when used in combination with specific diet and lifestyle interventions. This combination approach to treating PCOS involves using diet and lifestyle interventions to reduce the potential negative side-effects of PCOS – for example ensuring sufficient Vitamin B12 is obtained through diet or supplementation.

So, should you use Metformin for PCOS?

Whilst metformin certainly has some promise in treating the symptoms of PCOS, it seems unlikely to make a significant positive difference when used in isolation. The best advice would be to speak to your family doctor to discuss whether it would be right for your own specific circumstances – and maybe to give it a trial if you are both in agreement. Do let your doctor know though if you experience any negative side-effects.

My approach though is always to get to the root of an issue to see if we can address the underlying causes. In the case of PCOS, we know it is closely related to insulin resistance – and the diet & lifestyle/ exercise interventions I recommend are very much focussed on removing the underlying causes of insulin resistance – not just treating the symptoms. 

For example, switching to a predominantly wholefoods diet, with plenty of frequent but short bouts of high-intensity activity can have a much greater impact on your PCOS symptoms, as well as improving many other aspects of your health – with no side-effects! If you would like to find out more, you might want to consider a 2-week free trial to my Enhanced Energy membership programme.

So what about you – what has your experience been with using metformin for PCOS symptoms? Please let me know in the comments below!