Metformin for PCOS: Everything You Need To Know

Metformin is most commonly associated with the treatment of type 2 diabetes. 

Some medications are used “off-label” to treat other conditions as well. 

Metformin can treat PCOS, a hormonal and metabolic disorder impacting women worldwide.

What is PCOS, and how can metformin help as part of the treatment? Keep reading to find out.

What is metformin?

Metformin is one of the most commonly prescribed medications for type 2 diabetes, but it can also treat metabolic conditions like PCOS. The generic name most commonly prescribed is metformin, and the brand name for metformin is Glucophage.

Metformin is in a drug class called biguanides. Biguanides help reduce the amount of sugar your liver makes while improving insulin sensitivity, which helps reduce high blood sugar. There are two types of metformin – regular and extended-release (XR).

The common dosage for metformin ranges from 500 milligrams to a maximum of 2,550 milligrams per day. Healthcare providers usually recommended to split the dose among meals, typically three times per day. 

RELATED: Metformin Recall: Is Your Medication Affected?

What is PCOS?

Polycystic ovary syndrome (PCOS) is a hormonal disorder that affects women. For some women with PCOS, their ovaries produce too many androgens, a type of male sex hormone. 

The ovaries can also form many small, fluid-filled sacs called cysts. Poly means “many,” and cystic refers to these cysts, so polycystic means “many cysts.” 

Polycystic ovary syndrome is one of the leading causes of infertility in women. High levels of androgens can make it difficult to ovulate, which is when an egg is released to be fertilized. PCOS patients typically have long, irregular menstrual cycles since they don’t ovulate very often.

Polycystic ovarian syndrome is estimated to impact 4-20% of women of reproductive age worldwide. It often affects women who are considered overweight or obese, but it can occur in lean women as well.

Some of the causes of polycystic ovarian syndrome include:

  • High insulin levels and insulin resistance: Higher levels of androgens are associated with insulin resistance, which means that your body doesn’t use insulin effectively, which can result in high blood sugar levels over time. Insulin resistance is linked with polycystic ovary syndrome.
  • Low-grade inflammation. Low-grade inflammation can stimulate polycystic ovaries to produce androgens, so inflammation may lead to polycystic ovary syndrome.
  • Heredity. You’re more likely to develop PCOS if your mother or sister also has it.

Having PCOS increases your risk of developing type 2 diabetes mellitus as well as gestational diabetes.

RELATED: PCOS and Diabetes: What You Should Know.

Get Your FREE Diabetes Diet Plan

  • 15 foods to naturally lower blood sugar levels
  • 3 day sample meal plan
  • Designed exclusively by our nutritionist

By clicking “Download Now”, I agree to Ben's Natural Health Terms and Conditions and Privacy Policy.

Symptoms of PCOS

Several PCOS symptoms may arise, such as:

  • Missed periods, irregular periods, or very light periods
  • Ovaries that are enlarged or have many cysts
  • Excess body hair, including the chest, stomach, and back (hirsutism)
  • Weight gain, especially around the belly
  • Acne or oily skin
  • Male-pattern baldness or thinning hair
  • Infertility
  • Small pieces of excess skin on the neck or armpits (skin tags)
  • Dark or thick skin patches on the back of the neck, in the armpits, and under the breasts (acanthosis nigricans, a symptom of insulin resistance)

Some women with PCOS might have normal menstrual cycles. A thorough health exam including blood work (to test for hormone imbalances and insulin resistance) and possibly an ultrasound of the ovaries may be necessary in some cases.

How metformin can help PCOS

Metformin can help treat a common root cause of PCOS, which is insulin resistance. Metformin helps sensitize cells to insulin which helps lower blood sugar levels. The drug metformin may help improve hormonal imbalances and regulate irregular menstrual cycles.

Metformin treatment might help increase ovulation rates in women with polycystic ovary syndrome. However, taking metformin for PCOS isn’t the recommended first-line of therapy for those wanting to achieve pregnancy imminently. 

For women with PCOS wishing to conceive, other medications like letrozole or clomiphene citrate (Clomid) are more effective at inducing ovulation.

Research shows metformin treatment can inhibit androgen production, which can help lessen some unwanted side effects of PCOS, like unwanted hair growth. Lowering testosterone levels, the main androgen, may help achieve better hormonal balance helping to regulate menstrual cycles.

A study found that obese women lost weight due to metformin treatment. Weight loss can improve insulin sensitivity and improve PCOS symptoms.

Side effects of metformin for PCOS

The most common metformin side effects are gastrointestinal-related. If you start taking metformin for PCOS, you may experience some of these side effects:

Metformin treatment might also reduce your body’s ability to absorb vitamin B12 in your stomach. Approximately 6-30% of people taking metformin experience vitamin B12 deficiency. According to studies, the higher the metformin dose, the greater the risk of vitamin B12 deficiency. 

Vitamin B12 is important for creating DNA and red blood cells. Vitamin B12 deficiency can lead to anemia, which is when you have lower levels of red blood cells than is healthy. 

Anemia from vitamin B12 deficiency is pernicious anemia and comes with symptoms such as:

  • Weakness, tiredness, or lightheadedness
  • Heart palpitations and shortness of breath
  • Pale skin
  • A smooth tongue
  • Constipation, diarrhea, loss of appetite, or gas 
  • Nerve problems like numbness or tingling, muscle weakness, and problems walking
  • Vision loss
  • Mental problems like depression, memory loss, or behavioral changes

You typically treat vitamin B12 deficiency with vitamin B12 injections. Oral supplements aren’t usually used to treat pernicious anemia because the issue lies in the stomach’s ability to absorb vitamin B12.

RELATED: Metformin Diet: 5 Foods To Eat and 6 To Avoid.

Foods to avoid when taking metformin for PCOS

1.  Sugary drinks

Sugary drinks like soda, sweetened teas, flavored coffee drinks, energy drinks, among many others are very high in added sugar.

Drinking sugary drinks increases your blood sugar levels very quickly. Blood sugar spikes can worsen insulin resistance. Since PCOS often stems from insulin resistance, it’s best to avoid sugary drinks so metformin can more easily do its job to help improve insulin sensitivity.

2. Alcohol

Drinking alcohol can lower your blood sugar levels. If you drink a lot of alcohol while taking metformin for PCOS, you might develop even lower blood sugar levels. 

If you do choose to drink alcohol while taking metformin for PCOS, try to limit it to no more than one drink per day.

3. Foods with added sugar

Added sugar isn’t always easy to spot. Sugar is added to foods that might otherwise seem healthy like yogurt, dried fruit, some nutrition bars, and granola. 

Like sugary drinks, food high in added sugar can worsen insulin resistance and PCOS symptoms. Keeping a food journal to track your added sugar intake can help you identify what your baseline added sugar intake is. 

The American Heart Association recommends limiting your added sugar consumption to fewer than 25 grams per day. 

4. Refined grains

Refined grains are stripped of their nutrient- and fiber-rich parts, leaving behind a lower-fiber, lower-nutrient grain. These types of grains are more likely to raise your blood sugar levels and worsen insulin resistance.

White bagels, flour tortillas, white bread, and white rice are just a few examples of refined grains that you should try to avoid if you’re taking metformin for PCOS.

5. Fried foods

One of the more common side effects of metformin is digestive upset. High-fat foods can worsen stomach issues because they take longer to digest and sit in your stomach longer.

Fried foods are also higher in calories which can contribute to weight gain. Cutting back on fried foods might help you lose weight, which can improve insulin sensitivity and PCOS symptoms.

If you’re experiencing stomach side effects while taking metformin for PCOS, try cutting back on fried foods to see if that’s part of the culprit.

Foods to eat when taking metformin for PCOS

1. Nuts

Nuts are composed mainly of healthy unsaturated fats as well as protein and fiber. These healthy fats can help improve your heart health as well as promote healthy blood sugar levels. This is an important thing to consider since having PCOS increases your risk of having abnormal cholesterol levels.

Eating foods with protein and fat (like nuts) when you eat carbohydrates can help slow the rise in your blood sugar after eating. For example, eating a handful of nuts along with some fresh fruit will likely raise blood sugar less than eating fruit alone. 

Eating foods high in omega-3 fatty acids (walnuts are a great source) can help fight inflammation. Some women have inflammatory PCOS, so eating anti-inflammatory foods with omega-3 fatty acids might help improve their symptoms.

2. Protein-rich foods

Foods like chicken, fish, eggs, lentils, and quinoa are rich in protein and don’t raise your blood sugar levels significantly. According to the Plate Method, one-quarter of your plate should consist of protein at meals.

Protein also helps boost satiety, which means it can help you stay fuller in between meals, which can be helpful for weight loss.

Salmon is especially rich in omega-3 fatty acids while being low in saturated fat, making it an excellent choice if you’re taking metformin for PCOS.

3.  Non-starchy vegetables

Most vegetables are low in carbs and rich in fiber so they don’t raise blood sugar levels significantly. Vegetables are also a great source of vitamins and minerals

Richly colored fruits and vegetables are good sources of antioxidants, which help fight inflammation. Dark green leafy vegetables, berries, and rich orange-colored vegetables are especially beneficial due to their rich nutrient content.

Aim to include plenty of non-starchy vegetables while taking metformin for PCOS. Some examples of non-starchy vegetables include:

  • Artichoke
  • Asparagus
  • Beans (green, wax, Italian)
  • Beets
  • Brussels sprouts
  • Broccoli
  • Cabbage (green, bok choy, Chinese)
  • Carrots
  • Cauliflower
  • Eggplant
  • Green leafy vegetables (collard, kale, mustard, turnip)
  • Jicama
  • Kohlrabi
  • Leeks
  • Mushrooms
  • Okra
  • Onions
  • Peapods
  • Peppers
  • Radishes
  • Rutabaga
  • Salad greens (chicory, endive, escarole, lettuce, romaine, spinach, arugula, radicchio, watercress)
  • Sprouts
  • Squash (cushaw, summer, crookneck, spaghetti, zucchini)

Metformin alternatives for PCOS: natural and pharmaceutical

3 natural alternatives

Myo-inositol and D-chiro inositol

These vitamin-like substances have insulin-mimetic properties, which means they help increase insulin levels. Myo- and D-chiro inositol have been studied for their ability to improve insulin sensitivity and are often recommended for women suffering from PCOS to reduce symptoms and improve fertility. 

Inositol can improve blood sugar levels in PCOS women, and it’s even been studied for the potential to reduce the incidence of type 2 diabetes in children.

Inositol has been studied in direct comparison with metformin in insulin-resistant women. Both metformin and myo-inositol had similar positive effects on insulin levels, fasting blood sugar, and hormone levels in PCOS women. 

Another study found that inositol was more beneficial than metformin at reducing high testosterone in women with PCOS.

Inositol can be found in different blends (e.g., a mix of D-chiro and Myo-inositol), dosages, and forms, including powders and capsules for use as a natural metformin alternative.


Berberine is a compound we find in plants and we can use it as a natural metformin alternative for polycystic ovary syndrome. It may improve insulin sensitivity, reduce blood triglyceride levels, and reduce waist circumference. Berberine may also assist with weight loss.

N-acetyl-cysteine (NAC)

Your body uses N-acetyl-cysteine to make antioxidants. According to a small study, NAC improves insulin sensitivity in women with insulin-resistant polycystic ovary syndrome. 

Another study found that NAC improved glucose intolerance (another word for high blood sugars/insulin resistance) in diabetes-prone mice. 

Polycystic ovary syndrome may stem from underlying inflammation. NAC acts as an antioxidant and helps to fight inflammation

3 other drugs for PCOS

Some women may need fertility treatment if their PCOS is keeping them from getting pregnant. Fertility drugs like Clomid and letrozole (Femara) are two common ovulation-induction medications. 

These drugs help increase the pregnancy rate for women suffering from infertility due to irregular ovulation patterns from polycystic ovary syndrome.

Hormonal birth control pills

Hormonal birth control pills can mask the symptoms of polycystic ovary syndrome, but they don’t cure it. Some women with polycystic ovary syndrome notice improvements in their skin and hair growth on birth control.

Spironolactone (Aldactone)

This drug can help bind excess androgens and improve symptoms of high androgens like hair growth and acne. You shouldn’t take this medication if you’re pregnant or planning to become pregnant since it can cause congenital disabilities.

Eflornithine (Vaniqa)

You administer this medication in cream form to help slow unwanted hair growth from excess androgens.

Lifestyle changes to help manage PCOS

Weight loss, especially in obese women or those who are overweight, can improve insulin sensitivity and reduce negative side effects. Making sustainable healthy lifestyle changes may promote weight loss, but they might also help reduce symptoms even if you don’t lose weight.

Get regular physical activity

Getting more movement is one of the best ways to improve insulin resistance and help manage polycystic ovary syndrome. Your muscle tissue takes up glucose during exercise, even when you’re insulin resistant. 

Blood sugar levels tend to be lower after being active and can even remain lower for up to 24 hours after physical activity.

Aim to get 30 minutes of moderate to vigorous physical activity most days of the week, with a goal of at least 150 minutes per week. Strength training, such as weight lifting, bodyweight exercises, or other resistance training can also help improve insulin sensitivity and PCOS symptoms.

Get enough sleep

Not getting enough sleep can worsen insulin resistance and raise your risk of developing type 2 diabetes. Poor sleep can disrupt your body’s hormones which influence the foods you crave and how hungry you feel, leading to increased sugar cravings and potential weight gain.

Cut back on sugars

Added sugars are a significant problem in many processed foods. Cereals, yogurts, granola bars, and even savory foods can have sugar added to them, which can spike blood sugar and insulin levels.

Check the nutrition facts labels on foods and aim to get no more than 50 grams of added sugar per day, with fewer than 25 grams being the ideal goal per the American Heart Association.

Watch your carbohydrate intake

Carbohydrates (carbs) turn into sugar when digested, so they have a large impact on blood sugar levels and insulin resistance. A high-carbohydrate diet may worsen insulin resistance and PCOS symptoms, especially one high in refined carbohydrates and sugars.

Grains, fruits, starchy vegetables, and some dairy products contain carbohydrates. Aim to make half of your plate non-starchy vegetables, a quarter of the plate protein, and a quarter of the plate starch, similar to the Plate Method.

Carbohydrates aren’t bad, but not all carbs are created equally. Healthy carbs to include in your diet include whole grains, fruits, vegetables, and unsweetened dairy. 

A Mediterranean diet may be beneficial in improving polycystic ovary syndrome symptoms while also helping to reduce your risk of heart disease.

Get enough magnesium

Women with polycystic ovary syndrome are more likely to be deficient in magnesium. Magnesium not only helps promote relaxation to help manage stress levels, but it might also play a role in insulin resistance.

Some signs of magnesium deficiency can include fatigue, muscle weakness, stiffness, and muscle spasms. 

The recommended dietary allowance (RDA) of magnesium is between 310-320 milligrams per day for women, with those needs increasing slightly during pregnancy.

Some magnesium-rich foods include:

RELATED: PCOS Diet: Foods To Eat And Foods You Should Avoid.

Consider a trial elimination diet

While the evidence is primarily anecdotal versus scientific, some women find they can manage their polycystic ovary syndrome better by eliminating certain foods from their diets. 

Gluten, soy, refined sugars, and dairy are common foods that some women find as “triggers” for worsening their polycystic ovary syndrome symptoms. 

Not all women will notice an improvement in their symptoms when avoiding these foods, though. Elimination diets aren’t recommended for those women with a history of restrictive eating habits or eating disorders since they may cause a relapse in these unhealthy behaviors.


Polycystic ovary syndrome is a complex hormonal and metabolic condition that typically stems from insulin resistance. It’s possible to have polycystic ovary syndrome without insulin resistance, but it’s not as common. 

Treatment of polycystic ovary syndrome can include metformin in some cases, as well as natural alternatives which help improve insulin sensitivity.

Healthy lifestyle habits are one of the best types of treatment for PCOS. These lifestyle habits mirror the recommendations for people with diabetes since both can stem from insulin resistance.

Explore More

natural metformin

5 Natural Alternatives to Metformin.


  1. Shoupe D, Lobo RA. The influence of androgens on insulin resistance. Fertil Steril. 1984 Mar. 
  2. Practice Committee of the American Society for Reproductive Medicine. Electronic address:; Practice Committee of the American Society for Reproductive Medicine. Role of metformin for ovulation induction in infertile patients with polycystic ovary syndrome (PCOS): a guideline. Fertil Steril. 2017 Sep.
  3. Hirsch A, Hahn D, Kempná P, Hofer G, Nuoffer JM, Mullis PE, Flück CE. Metformin inhibits human androgen production by regulating steroidogenic enzymes HSD3B2 and CYP17A1 and complex I activity of the respiratory chain. Endocrinology. 2012.
  4. Harborne LR, Sattar N, Norman JE, Fleming R. Metformin and weight loss in obese women with polycystic ovary syndrome: comparison of doses. J Clin Endocrinol Metab. 2005.
  5. Fulghesu AM, Ciampelli M, Muzj G, Belosi C, Selvaggi L, Ayala GF, Lanzone A. N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome. Fertil Steril. 2002.
  6. Deswal R, Narwal V, Dang A, Pundir CS. The Prevalence of Polycystic Ovary Syndrome: A Brief Systematic Review. J Hum Reprod Sci. 2020.
  7. Kim J, Ahn CW, Fang S, Lee HS, Park JS. Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes. Medicine (Baltimore). 2019.
  8. Mancini M, Andreassi A, Salvioni M, Pelliccione F, Mantellassi G, Banderali G. Myoinositol and D-Chiro Inositol in Improving Insulin Resistance in Obese Male Children: Preliminary Data. Int J Endocrinol. 2016. 
  9. Nas K, Tűű L. A comparative study between myo-inositol and metformin in the treatment of insulin-resistant women. Eur Rev Med Pharmacol Sci. 2017.
  10. Jamilian M, Farhat P, Foroozanfard F, Afshar Ebrahimi F, Aghadavod E, Bahmani F, Badehnoosh B, Jamilian H, Asemi Z. Comparison of myo-inositol and metformin on clinical, metabolic and genetic parameters in polycystic ovary syndrome: A randomized controlled clinical trial. Clin Endocrinol (Oxf). 2017 Aug.
  11. Kelly GS. Clinical applications of N-acetylcysteine. Altern Med Rev. 1998.
  12. Falach-Malik A, Rozenfeld H, Chetboun M, et al. N-Acetyl-L-Cysteine inhibits the development of glucose intolerance and hepatic steatosis in diabetes-prone mice. Am J Transl Res. 2016;8(9):3744-3756. Published 2016 Sep 15.
  13. Gao X, Lampraki EM, Al-Khalidi S, Qureshi MA, Desai R, Wilson JB. N-acetylcysteine (NAC) ameliorates Epstein-Barr virus latent membrane protein 1 induced chronic inflammation. PLoS One. 2017 Dec.
  14. Hamilton KP, Zelig R, Parker AR, Haggag A. Insulin Resistance and Serum Magnesium Concentrations among Women with Polycystic Ovary Syndrome. Curr Dev Nutr. 2019. 
  15. Duleba AJ, Dokras A. Is PCOS an inflammatory process?. Fertil Steril. 2012.

Top Products

Total Health


Glucose Control