Metformin is a type of medication used to treat Type 2 Diabetes. Because there is a strong link between diabetes and PCOS, metformin is now commonly proscribed to treat PCOS. But should it be? What is the real relationship between metformin and PCOS? Can Metformin used for PCOS help lessen PCOS symptoms?
Metformin used for PCOS: The Science
PCOS is an infertility condition that often causes acne, facial hair growth, balding, low sex drive, weight gain, difficulty with weight loss, and mental health disturbances such as depression and anxiety in approximately 15% of women. It is also associated with a myriad of health conditions, spanning from diabetes to hypothyroidism and to heart disease.
PCOS is, in short, not a condition to sneeze at.
PCOS is a condition of hormone imbalance. With PCOS, male sex hormones such as testosterone and DHEA-S rise relative to the female sex hormones estrogen and progesterone. (…Roughly speaking – it’s complicated. For a full-blown account of the science of PCOS and how it affects you, see here.)
Elevated testosterone is very often the primary culprit in causing PCOS. (But not always! For one of my most thorough accounts of other things that can cause PCOS, see here.) Insulin causes testosterone levels to rise because insulin tells the ovaries to produce testosterone.
Basically, elevated insulin causes elevated testosterone, which causes PCOS.
This is where metformin comes into play. Metformin lowers blood sugar levels below what they would otherwise be after a meal. This is because it intervenes with the liver’s interaction with and production of glucose. Insulin is the body’s way of dealing with blood sugar. If blood sugar is lower, then insulin will be lower, and thus testosterone will be lower.
Metformin decreases blood sugar, which lowers insulin, which lowers testosterone.
Metformin used for PCOS: Is it Effective?
That depends on who you ask, and what you are trying to achieve.
Statistically, metformin has been shown to reduce LDL cholesterol (the bad cholesterol) and triglycerides (perhaps even worse for heart disease) in patients with Type 2 Diabetes. It is hotly contested whether metformin has a significantly helpful effect on overall cardiovascular health for patients with Type 2 Diabetes worldwide. It is definitely true that many people have benefited from metformin in terms of their ability to manage sugar and keep insulin levels in check.
In fact, metformin has been shown to help prevent Type 2 Diabetes in people who are insulin resistant and at risk of developing Type 2 Diabetes. BUT – and this is a point I will make several times – it has been shown to be radically less effective than a whole foods diet and moderate exercise. This study compared the two, and diet and exercise were shown to be 34% effective. Metformin, only 18.
Insofar as metformin can help mitigate the symptoms associated with PCOS such as acne and facial hair, it is often quite successful. The evidence supporting this is robust. Metformin used for PCOS does help reduce symptoms in women… at least for those who suffer from insulin resistance.
Metformin used for PCOS: The Limits
There are three primary limits to the efficacy of Metformin for PCOS:
1) Metformin may not be the most effective fertility treatment
So far as your fertility is concerned, clomiphene may be more effective than metformin (and diet and lifestyle more effective yet than that). This is a hotly debated topic in the world of metformin and PCOS. All fertility treatment options should be discussed with your doctor if fertility is your primary aim.
2) Metformin is not as effective as diet and lifestyle in the long run
Just as Metformin loses in long-term efficacy against diet and lifestyle (see my personal recommendations for diet and lifestyle in a blog post or in my PCOS program here) for insulin management and diabetes prevention, so it also loses in terms of managing the symptoms of PCOS.
3) Every person’s PCOS is different – Metformin does not work for everybody
Perhaps the most important point for me to make is that Metformin does not work for everybody.
While many women suffer PCOS because insulin resistance causes their testosterone levels to rise, this is actually only the case for about 70% of women with PCOS. For everyone else with PCOS, metformin’s effects will be minimal at best, and may in fact be harmful.
There are many different things that can cause PCOS other than high testosterone.
- low estrogen levels
- low progesterone levels
- birth control pill usage
- excessive exercise
- the MTHFR gene
- IBS and other gut problems
- and restrictive diets can all contribute to PCOS
If any of these are your primary problem, and not the excess testosterone that comes from elevated insulin levels, other treatments may be more effective for you.
If you do not know what is causing your PCOS, the first step towards getting better is to get some bloodwork done, educate yourself about PCOS and what your personal kind of PCOS may be, and find out!
Other Potential Drawbacks of Metformin used for PCOS
While Metformin does not appear to cause any significant or life-threatening problems, it does come with a host of negative side effects that can are short and the long-term.
The most commonly reported side effects of Metformin are gastrointestinal: at least some of gas, nausea, cramps, bloating, discomfort, and diarrhea are reported in upwards of 50% of cases.
Metformin increases homocysteine levels in the long-term. Homocysteine is a by-product of the body’s natural detox processes, and it is toxic in high levels. Elevated homocysteine has been shown to be associated with inflammation, heart disease, cancer, and just about every non-communicable disease out there (including PCOS!).
Metformin appears to influence thyroid hormone levels, though the mechanism and implications are poorly understood.
Metformin reduces testosterone levels, which can upset hormone balance. I personally suffered severe depression – suicidal depression – when I experimented with taking Metformin. I only had to take it for six days for the storm of sobbing and suicidal thoughts to hit. I stopped taking it, the depression went away, and then I tried again and the depression came back. Obviously everybody is different – but this is a real risk. Anxiety is another threat, as is low libido, poor memory, and sleep quality.
It is also worth noting that in the case of weak kidneys, Metformin can cause kidney failure due to lactic acidosis.
The Real Reason Doctors Proscribe Metformin for PCOS
There are many reasons doctors use metformin to treat PCOS. Most importantly, they know that it has been demonstrated to be helpful for a lot of women with PCOS. Yet it is also important to remember that doctors tend to over-proscribe medication as a general rule.
Doctors and patients both know that it is easier to take a pill than it is to make changes. (It also happens to be more profitable for the doctors, but they are not the only ones to blame here, since patients are usually the ones asking for the pills.)
But is it better?
It has been demonstrated over and over again that the most effective way to treat PCOS is to eat a whole foods diet and to exercise a few times a week. You can get very specific about the ways in which you do this, and I do go into great depth on these strategies in my program on overcoming PCOS here. Nevetheless the most important point here is to remember that dietary changes are healthy, natural and long-lasting.
What are your experiences with metformin and PCOS? Do tell! I’d love to hear if it has worked for you – or what you like better!
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This blog has really hit home with me and I’d love to share my experience if it can help others. I was diagnosed with pcos 4 years ago after a ruptured cyst left me in agony. I was treated with steroids and antibiotics and was advised low progesterone, estrogen and the birth control pill were causing these problems. I was prescribed metformin but after some research I decided not to take it.
Fast forward a year or so and I got married and started trying for a baby. My doctor told me that I required ovulation induction and metformin was my only option to control insulin levels and get pregnant!! I was given femara (a cancer drug that induces ovulation) metformin, estrogen treatment, progesterone treatment and a whole host of vitamins and supplements that were to boost my chances. Month after month it failed and we tried a different cocktail of drugs including changing dosage of metformin as well as switching to clomid for ovulation induction. We did this for 14 months without any success. It was heart wrenching being told I would only ovulate with these drugs and the next steps were iui or ivf.
As far as the side effects it was awful! Metformin made me feel bloated gassy and dizzy! Let’s not even talk about the effects of the clomid! The clomid crazy’s really does exist!! I remember fainting one day at a golf event in front of hundreds of people who thought I’d been drinking too much. The truth was my metformin dosage had been increased and my body couldn’t handle it! Vommitting and days of feeling ill were par for the course.
Before I embarked upon this journey I had found the paleo diet and tried it out for a few months with not the best success. I found it hard to keep up with my intensive exercise programme on a low carb diet and didn’t want to supplement with too many carbs in case I got fatter! I went back to my low GI gluten free diet which seemed to work as I was in the best shape of my life after having always struggled with my weight.
During the fertility treatment i stuck to my diet yet gained a copious amount of weight. Good bye six pack and toned legs. I was back to my teen years of fit but curvy! I didn’t care because I wanted to get pregnant and this was what I thought my body needed!
After more research and more struggling I read enough about paleo and the potential affects on pcos. I also ready about soy and the very scary revelation that it was interfering with my estrogen levels. I cried when I read the research and it spurred me to read more and educate myself. The truth is I was living in a fantasy world of desperation to get pregnant as fast as I could. It would solve all my issues with pcos and I wouldn’t care about my weight or hormones. But this was not to be.
I decided to stop the drugs and cut out the soy products I had been eating for years because dairy upset my IBS and I needed protein to support my intense exercise!! I followed a strict paleo diet for 5 months and found my body reacted in the way it was meant to. I leaned out a bit of the weight I’d gained and finally got pregnant! Not one pill passed my lips for 5 months and I could even feel myself ovulating each month. My insulin levels were the lowest they had been and I eased up on the intense exercise. I am currently 7 months pregnant and following a paleo based diet with the addition of oats rice and quinoa now and again. I’m healthy and still exercising to keep active.
I tell people about my story and they look at me like I’m crazy! How can diet impact your chances if getting pregnant! I tell them about this website and Chris kresser and Rob wolf and tell then to read it but they never do. They think I’m crazy! I don’t mind! I know what worked and it certainly wasn’t the drugs! I feel back in control of my body and my hormones and whilst I’m aware this will always be a battle of the bulge and the hormones I feel I have the knowledge and power to keep it under Control and know what works for my body much better than any doctor ever could
I hope this can help and support some other women in their journey..
Thank you for sharing, Amanda. It’s an honor that you recommend my site and very exciting to have you with us, and that your journey is going so well. SUPER inspiring 🙂
To help with my PCOS recovery (and I believe I have type 1 PCOS – insulin resistance – or rather, elevated-blood-sugar-induced PCOS), my naturopath prescribed Berberine. Berberine is an all-natural supplement that has been shown to be as effective as Metformin: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2410097/
This, in conjunction with several other supplements she prescribed, have REALLY helped with my PCOS. My cycle is getting more and more normal every month, my weight is dropping, and most importantly, I feel MUCH better.
I hope that continuing on my whole foods diet and following Stefani’s other guidelines, I may be able to stop taking Berberine and the other supplements. But, for now it seems to be helping without any nasty side effects. I’m curious to hear if you’ve looked into this one at all! Seems like it may be a better option for those who are told to take Metformin.
Thank you for all that you do, Stefani! <3
You are very smart to fore go taking Metformin,it is a nasty drug, most glucose lowering medication meds. are I was on Januvia for type 2 diabetes, but also have Fibromyalghia and all the side effects were the same as Fibromyalghia flare ups..I was sick all the time, so I found an alternative that included Bererine and it is working pretty good.I know this blog is not about me a 72 year old female, but I wanted to reach out to you to tell you how great it is to see that others search for alternatives.
I was prescribed Metformin when I was 19. I was living in the dorms at my college and was in a bad pattern of starving then overeating. I was taught that fat was what made people fat so I ate mostly salads with vinegar on them and heaping cups of fat free soft serve from the frozen yogurt machine in the dining hall. In my room I had an air popper and ate cups and cups of popcorn.
After one year of this I was having low blood sugar reactions. I fainted numerous times at my job as a waitress and in my classes. My parents were worried so I went home to have blood work done. They found my blood sugar dropped very low in between meals and upon waking. They also found I had elevated levels of male hormones. My doctor prescribed Metformin and a weird low fat/low carb diet which suggested I eat mostly egg whites and fat free ground turkey and “grilled tomatoes”- like any college student grills tomatoes! My mom thought it sounded like crap so she suggested I eat a Mediterranean diet- which is more or less what I eat now but without the grains.
The metformin made me lose weight and I felt good, but did have horrible stomach issues. I was bloated after everything I ate. I ended up going off of it when I graduated because I didn’t have health care and it cost too much. I was fine when I went off of it, but that was mainly because by then I had researched so much about PCOS (a diagnosis I was never given but my symptoms and blood work suggested) I limited carbohydrates, cut out sugars and gluten and made sure to have a fat at every meal, that was 9 years ago and I’m still eating that way and have not fainted again.
I’m not sure if I ever had PCOS- I’ve never had acne, hair growth or low sex drive, I only had the fainting spells and horrible hunger pains – I was hungry all the time before cutting out grains.
I don’t like metformin because it ruins your health reports forever. I was never able to qualify for affordable insurance (pre-existing condition) after taking it at 19. I didn’t get health care again until I was 29 and landed a full time unionized teaching position where my health history was not looked at.
My advice for young people- you will heal quickly if you eat right! don’t take the pills!
I became a big fan of the paleo diet when it significantly improved my psoriasis better than any Rx cream or dermatologist treatment. As a physical therapist, I have always tried to have a good balance in my fitness routine with running, yoga, and strength training. I’m 5’5″ and 125 lbs so a normal healthy weight. All of that being said , I was so discouraged when my acne and hair growth were spiraling out of control, no matter what diet changes I made, so I finally gave in to taking metformin. It’s been about 3 months and my skin is clearer and I’ve stopped growing a beard.. Hopefully my fertility is better too but we’re not quite ready to find out 🙂 Just thought I’d share that sometimes we do need a little medical intervention! (Also I had ZERO GI symptoms which is rare)
Hi. I just shortly write that in my case metformin did wonders. I lost 30kg and got pregnant without any problems. Also my mood improved greatly. But I know women that didn’t react well to it. So as it was stated in the article it is a personal matter whether it is good for somebody or not.
I tried Metformin for my PCOS and lost 10 pounds in just a few weeks on it with no side effects! I didn’t want to stay on it forever though and once I got pregnant I got off of it. I recently read you can take inositol with folic acid and an omega 3 supplement and it can help just as much. Thoughts?
Worth a shot! You could always give it a try and switch back if you find it insufficient. Honestly metformin’s side effects seem to be minimal compared to other drugs so if it helps you I’m on board 🙂
Metformin has been a miracle drug for me. I hope that your negative post doesn’t discourage women with PCOS from trying it because what you fail to state is how many women with PCOS for whom Metformin is very successful.
One day about 16 years ago I was reading a Dear Abby column that said that there were new treatments for PCOS. I’d had the symptoms of PCOS from the minute puberty hit (and well before, once I learned about the metabolic connection to PCOS) even though I was very thin. I had severely irregular periods and when I did have them they were very heavy, long, painful. I had severe acne, and severe reactive hypoglycemia. Now we know those are classic symptoms, but in those days the connections had not been made between acne, hypoglycemia and irregular periods. I went through years of infertility treatments culminating in two IVF procedures to conceive our only daughter, who was then 8 years old. We had long since given up on having more children. I wanted to find new treatments for PCOS to relieve the painful, difficult periods and for my overall health (my mother and grandmother had Alzheimer’s and they were just beginning to make that connection to insulin resistance, too).
Fortunately, I found a wonderful endo who prescribed BOTH a low carb diet for me (Protein Power by the doctors Eades) AND Metformin. The years of fertility hormones had packed on the pounds. He advised me to start the diet first so that my adjustment to Metformin would be easier. So I started Protein Power and did well with that. When I added in Metformin, within 30 days I had my first EVER ovulatory period without fertility drugs. I was 40 years old.
When I started this regimen the endo told me that I could get pregnant, and I laughed in his face. I’d been infertile my entire life and no natural pregnancy in 11 years of marriage without birth control. While Protein Power seemed to be helping me lose weight (a whopping 5 lbs when I had that first ovulatory period!), it took Metformin to really see a difference.
I was approaching my 41st birthday when I found out, to my utter surprise and delight, that I was pregnant. I had an easy pregnancy and a healthy baby who is a brilliant 15 year old honor student now. After her birth I went off Metformin and the symptoms of PCOS came roaring back immediately, even though I was trying to keep up with the lifestyle changes. I eventually gave up altogether. A few attempts at good diet and exercise failed and I gained a huge amount of weight and stacked up a bunch of other health issues as well. It took me 12 years to convince my health care provider (the good endo was long gone) to put me back on Metformin, and that allowed me to turn things right around. I’m back into a great lifestyle of diet and exercise–instead of enabling me to avoid this, Metformin ENABLED me to get back to a healthier lifestyle by mediating the IR. I lost 75 lbs and I have kept it off for more than 5 years now. I sailed through menopause and my health issues have reversed, one by one.
Every once in a while a GP will suggest that I don’t really need Metformin, but I argue hard to keep it on board, because it has made such a huge difference in my life and I know what happens without it. My 15 year old has insulin resistant PCOS as well and I had no hesitation having her go on Metformin, instead of the usual birth control pills.
Of course Metformin doesn’t work for everyone, some people cannot get past the side effects, others don’t see any positive changes with it. But don’t forget to mention that many ARE helped by Metformin, and it’s certainly worth a try.
So great to read your story – of course I agree every body is different! Thank you so much for sharing 🙂
Yes..Metformin has had such a positive impact on my health. I recently experimented with not taking it for a week because I eat whole foods and very low carb, so I figured that with my lifestyle and diet, I could forgo the met. I was wrong. My IR returned, along with inflammation and weight gain. I take a low dose, and the side effects of not taking it are way worse in the short term and long term of taking it.
I can see where you are coming from and it’s great you got your health back and fell pregnant! What Metformin did for you is reduce blood glucose and thus insulin. Which is also what any of the paleo/keto/low carb/primal/AIP diets can do. Regulate insulin and the insulin responsible for triggering pcos in 70% of women and you regain fertility and health. Fat is key in these diets for blood glucose regulation and fertility (your hormones need fat). Metformin did what diet would do.
Metformin will work in women with insulin related pcos but not for women with pcos triggered by some other factor. The point being made is metformin is a bandaid solution that fixes the insulin problem for you. Diet fixes your bodies insulin mechanisms – the root cause. 70% of women. 30% mentions others not insulin related which will most likely not respond to metformin.
I am currently on metformin. I have been ttc for two years, i eat well, exercise plenty. But I was gaining weight. No specific diet, but whole grains and fruits and veggies. Only 1200-1500 calories a day. Still gaining weight. Not ovulating. I didn’t want to go on metformin after all my friends have been sick on it and I’ve heard so many horror stories. But I was desperate. I feel great! I’ve been on it for a bit over a month and have lost a steady 2 pounds a week. I feel more energetic. As far as mood, I see that more correlate with my progesterone. I take cycling progesterone and when I’m off it, I feel it dip. I struggle with depression and anxiety. As soon as I’m on it, it’s like the cloud lifts. Crazy. But perhaps I really needed metformin, Cause its been a totAl blessing to add to my diet and lifestyle changes to help me get started. Don’t wann be on it forever or even long term but for now it’s helpful.
I been on it for years, recently I stopped taking it to see what would happen. I take it for PCOS, but apparently it lowers systolic blood pressure also.
I stopped taking it for a week to see what would happen. Well, it was not fun. I felt very hormonal and moody. I could feel inflammation return. I gained weight within a week without any change to my diet or lifestyle. For me the benefits of metformin far outweighs any negative side effects (which I have yet to experience). So I can confidently say that metformin was the best choice for me.
It’s interesting to hear how it affects different people. It just goes to show that there’s a not a one size fits all fix. I have tried two different times to use Metformin (500 mg regular the first time and 500 mg extended release the second) and had to stop after only a brief time each try due to side effects. I became deeply depressed in a matter of days, alternated between hot flashes and chills constantly, my hands got tender and swollen, and I had constant fatigue. The dizziness just didn’t stop. I felt like I was coming down with something and every day it just got worse. The digestive issues were only a problem on the regular variety…but they were a problem the entire time I took it. It just wasn’t for me. Exercise works better in my case.
Metformin has been awesome for me. I exercise 5x a week and eat whole food/ low carb and watch my calories for 3 years now and I have continued to have bad acne, facial hair and thinning hair. Regardless of my tireless efforts I cannot lose any weight either. I feel I have been doing everything right with no progress. My doctor put me on 500mg metformin once a day and I am like a new person. My acne is gone, my beard is gone and my hair loss has almost diminished. I lost 10 lbs the first month. I haven’t had any bad side effects either. I am grateful for Metformin. It has given me a new confidence. I understand that it’s not for everyone, but it was the right choice for me.
How long did it take before you started seeing the results of diminishing facial hair and acne?
Matformin has an extended release tablet (for those of you having stomach issues). It has completely turned my life around.
For fertility, does 500mg extended release per day work? Asking for a friend who has lower GI issues with 1000/day. Her doc wants her to go to 1500/day.
Every body is different. It’s worth trying at a lower dose IMHO and then increasing on a monthly basis
I have been on metformin for two years for pcos, I do have side effects. About 3 months ago my pharmacy changed the brand of metformin that I take from heritage to aurobindo and I was so sick and felt horrible, it took me a week to figure out that maybe it was the difference in the brand name so I started researching different brand names of metformin and found out that the initial brand I had always taken had less fillers than the one they changed me to, I called my doctor and several pharmacies until I found the heritage brand and went and picked up the prescription,it made such a difference in how in felt, I would have never believed that fillers would make such a differnce. I struggle with weight mood changes and of course hair growth it is a struggle trying to find the right balance and diet. Always open to things people try and its nice to know your not alone.
Thank you for sharing about your experience. That’s so important <3 <3
I have PCOS and had to have a full hysterectomy due to pre cancer cells found. They want me to take Metformin but I have before and it makes me feel aweful. What options do I have? If I change my diet and exercise routine would that help? I just don’t want to feel like crap all the time chasing a toddler around..
I do think diet and exercise can help with that, yes <3
I’m now 30 yrs old and I’ve been diagnosed with PCOS at 20 and put on metformin when I was 22. I tried taking them as prescribed but it made me sick and I continued to gain weight rapidly and also started using the pill. It made me feel sick and I lacked energy all the time. From 90lbs I was at 120 with a belly pooch. When I turned 25 even with the proper use of medication and regular exercise my condition wasn’t getting better. My best friend who was a med student encouraged me to cut back on sugars and unhealthy fats and increse high intensity exercise. After I started making these lifestyle changes my doctor couldn’t even tell I was off the meds and said I was doing great. I’m 30 and my life is completely normal because I’ve made these changes a part of who I am.I’m the fittest and leanest I’ve ever been and I feel great all the time.
There is no doubt that metformin works, it does but making lifestyle changes for me feels safer and much more rewarding.
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