Metformin For Weight Loss In PCOS 2024: Benefits, Side Effects & More

Polycystic Ovarian Syndrome, also known as PCOS, is a hormonal disorder that impacts 5-15%^[1] of women worldwide. The hormonal imbalances linked to this disorder impact the menstrual cycle, cause anovulation, and an excess production of circulating androgen hormones. Women with PCOS experience symptoms like excessive hair growth, acne, infertility, and weight gain.

Metformin is used for treating type 2 diabetes mellitus and impacts how your body regulates insulin. It has recently gained attention as a treatment for women with PCOS, as the underlying mechanism in this disorder is rooted in insulin sensitivity. Researchers^[2] have postulated that PCOS patients may experience reduced symptoms by adjusting this sensitivity.

This article will explore how metformin impacts weight loss in women with PCOS and the research behind these claims. We will also explore its effectiveness in helping women lose weight, the correct dosage for losing weight, side effects, and how to maximize the benefits.

Metformin Weight Loss In PCOS: How Does It Work?

Research^[3] has shown that insulin resistance plays a significant role in the development of PCOS. Insulin is an important hormone that regulates glucose levels. When an individual has insulin resistance, the body’s cells become less responsive to the effects of insulin, resulting in higher levels of plasma glucose. Elevated glucose levels can lead to glucose intolerance, resulting in weight gain and an imbalance in other hormone levels that may exacerbate the symptoms of PCOS.

Metformin^[4] is a biguanide medication that is believed to address the underlying cause of PCOS. The mechanism of action of metformin involves making the body’s cells more sensitive to insulin, potentially mitigating the insulin resistance common in PCOS sufferers. This increased sensitization can cause insulin reduction, an improvement in glucose uptake by cells, and increased glucose utilization. By addressing insulin resistance, metformin helps to regulate glucose levels and encourage slimming down. 

PCOS metformin fat loss may also occur through other mechanisms,^[5] such as suppressing appetite and altering the gut microbiome. It may also impact^[6] how the body stores and processes certain types of fat, specifically brown fat, that influence metabolic factors. The exact mechanism behind how metformin assists people lose weight for each individual is still unclear.

In addition to the effects on insulin resistance, metformin appears to have other benefits^[7] in women with polycystic ovary syndrome such as, including reducing serum androgens, increasing fertility, regulating the menstrual cycle, resuming ovulation, and reducing miscarriage rates. Women with polycystic ovary syndrome PCOS who struggle with menstrual frequency, ovarian function, and elevated levels of circulating androgens can also benefit from metformin.

Does Metformin Cause Weight Loss In PCOS?

Yes. For most women with PCOS, metformin may be an appropriate medication to promote fat loss, but its effectiveness can vary among individuals based on various factors such as metformin dose and incorporation of lifestyle interventions. Metformin is currently not FDA approved for the treatment of PCOS, but research supports many treatment benefits.

In a 2023 review,^[8] which included a placebo controlled trial evaluating metformin in losing weight and reducing body mass index (BMI), it was reported that women taking metformin had a statistically significant reduction in BMI and a larger reduction of waist-to-hip ratio. For patients with polycystic ovary syndrome struggling to lose weight with lifestyle modifications alone, adding metformin into their treatment plan may help reduce body fat and encourage weight reduction.

Additionally, counting calories can help support shedding unwanted fat. It is important to know how many calories to consume in a day, to stay on track with fat loss.

Research^[9] has demonstrated that for the best outcomes in obese patients, combining both lifestyle interventions, such as diet and exercise changes, and metformin therapy resulted in the best fat loss outcomes for women with polycystic ovary syndrome PCOS. So, how long does it take to lose weight? Based on one review,^[10] it was reported that weight loss occurred anywhere from a few weeks to a few months.

The encouraging news is that women who lost this weight could also keep it off. A 2020 longitudinal study^[11] that evaluated the long-term effectiveness of metformin in women with polycystic ovary syndrome demonstrated a statistically significant decrease in BMI after the first year of therapy. One study^[12] also showed that women could keep the weight off at the three-year mark. Incorporating exercise, such as targeted belly fat exercises, can give you an added boost.

Metformin Dosage For PCOS Weight Loss

An essential factor in the metformin’s body mass index reducing effects of metformin is the dosage. Research^[13] has demonstrated higher doses of metformin are associated with more significant weight reduction in obese women. Patients taking 2,500 mg of metformin daily lost about twice as much weight as those taking 1,500 mg daily over the same time frame. It is important to discuss appropriate dosing with your medical provider if you are on metformin for PCOS and have questions about the best dose to help with losing weight.

The recommended dosage^[14] for metformin for women with PCOS looking to achieve losing weight may vary depending on individual factors and goals of treatment. Usually, 1,500 to 2,550 mg daily is needed to address insulin secretion associated with PCOS, leading to reduced body weight.

An issue with achieving such a high metformin dose is increasing the risk of gastrointestinal side effects that may make this medication intolerable for some women. The clinical effects of metformin are typically not achieved at a dose lower than 1,000 mg, so if a person cannot tolerate higher dosages due to side effects, they are unlikely to see any fat loss results, making fat loss with metformin difficult.

How To Take Metformin For Weight Loss

In order to maximize the effectiveness of metformin, there are several considerations in addition to just the correct dosage. The following are tips to ensure a smooth transition into metformin treatment for PCOS.

Take Metformin With Meals

To reduce the risk of gastrointestinal upset, metformin administration should occur with a meal so it is easier on the digestive system. At first, it is best to take it with your largest meal of the day, such as a healthy breakfast of bananas and oatmeal. 

You might want to know, is banana good for weight loss? Yes, they can help with regulating blood sugar and supporting a healthy diet.

Combine With Lifestyle Intervention

Metformin can help with losing weight on its own, but increasing physical activity, eating a whole and nutritious diet, and cutting out junk food can all contribute to reaching your personal fat loss goals. Here are some tips to lose weight naturally.

Follow The Prescribed Schedule

Make sure use the dosing schedule your doctor prescribes, such as the time of day to take the medication, taking doses consistently, and not changing your dosage without your doctor’s guidance.

Monitor For Side Effects

If you experience unwanted side effects, reach out to your doctor right away. They may lower your dosage or slow the tapering schedule. Excessive diarrhea may detox your body, but also lead to dehydration.

Side Effects

The main side effects associated with metformin treatment are the gastrointestinal symptoms^[15] of diarrhea, nausea, increased gas and bloating, reduced appetite, metallic taste in the mouth, and abdominal pain. The amount and severity of symptoms will vary from person to person, and in some cases will resolve on their own. Most women with polycystic ovary syndrome tolerate metformin very well especially if started at a low dose.

To avoid severe side effects^[16] your doctor will gradually administer metformin and slowly increase your dose based on the severity of side effects. The recommended starting dose is 500 mg daily, for the first few weeks of therapy.  Try taking it with a healthy breakfast, to support losing weight. As time goes on your doctor will slowly increase your dosage, usually by 500 mg per week, until you reach the effective dose you.

If you struggle with titrating up on metformin, your doctor may slow the increase in dosage to every three to four weeks. There is also an extended release version of metformin that may be associated with fewer side effects.^[17]

Other more rare, but serious side effects of metformin include issues with B12 absorption and lactic acidosis. These side effects are more common in people with certain medical conditions, such as renal insufficiency. Be sure to discuss other conditions you may have with your doctor before starting metformin.

Conclusion

Metformin is a common treatment option for PCOS in overweight individuals. Despite not being approved for PCOS, there is a substantial amount of research to back the benefits of this medication for women with polycystic ovary syndrome, both in the short and long term. Metformin PCOS weight loss before and after changes can be drastic.

The dosage of metformin and incorporating lifestyle modifications are important factors in the success of this drug working to reduce weight. Metformin can cause unwanted gastrointestinal side effects, so be sure to work with your physician to slowly increase your dosage to reach the effective dose without experiencing discomfort.