Neha Arti 
Metformin is an oral medication that may help some patients get pregnant. The drug may induce ovulation, giving you an opportunity to conceive.
Although metformin for fertility can be effective, only some PCOS patients will go on to have successful pregnancies. Experts believe the drug should only be prescribed to certain groups of people.
In this guide, you’ll learn what metformin for fertility is, who it’s effective for, and possible side effects.
Keep reading to understand if metformin could work for you.
What Is Metformin Used For?
If you’ve been prescribed the drug, you may wonder, “what is metformin used for?” When people take metformin for fertility, it’s considered off-label use. That means that while the FDA has approved the drug for other conditions, it hasn’t been officially approved for treating infertility.
Metformin, sold under the brand name “Glucophage,” is most commonly used to control blood sugar in type 2 diabetes patients. A doctor may prescribe metformin to:
- Help control glucose levels in blood
- Control amount of sugar absorbed from food
- Control glucose produced by liver
- Increase response to insulin
Many patients who are prescribed metformin also take additional medication to help manage their blood sugar.
Metformin may also reduce weight gain by reducing energy intake. While the drug may not cause weight loss, it doesn’t cause weight gain—which is a side effect with other type 2 diabetes medications. For this reason, metformin may be prescribed off-label as a weight loss aid.
What is Metformin Infertility Treatment?
A doctor may prescribe metformin for fertility for polycystic ovary syndrome (PCOS) patients. It’s not considered a “fertility drug,” but there’s some evidence to show that metformin can act as a fertility aid for women.
It’s not clear exactly how metformin infertility treatment works. In short, metformin may help people with PCOS ovulate. While there’s research to suggest the drug can boost ovulation, there’s conflicting research on whether that boost translates into conception and childbirth.
Some ovulation-inducing drugs, like Clomid, are taken on specific days of your cycle. Metformin is a bit different. It’s taken daily and the effect may not be as immediate. To see possible benefits of metformin in PCOS patients, it can take anywhere from 30 to 90 days.
In the next section, we’ll discuss the research on metformin and why and how it may work.
Benefits of Metformin in PCOS Patients
The research on metformin for fertility mainly concerns metformin in PCOS patients.
When metformin for fertility is prescribed, the patient typically has PCOS and is insulin-resistant. PCOS is a common cause of infertility. It happens when the ovaries don’t produce normal hormone levels. PCOS can cause:
- Irregular, fewer or no periods
- No ovulation
- Raises risk of diabetes (PCOS patients are four times more likely to develop type 2 diabetes)
Many PCOS patients classified as obese are hyperinsulinemic. Metformin can help those with PCOS control their insulin production, which can make conception more likely.
Below are the following possible benefits of metformin in PCOS patients.
Decreases Male Hormone Production
When you have PCOS, your body is producing an excess of androgen (a male hormone). Metformin helps reduce the amount of androgen produced, helping to balance the hormone levels.
May Induce Ovulation
When people with PCOS who are insulin-resistant take metformin, it can induce ovulation. Since ovulation is required for conception, metformin can create an opportunity for conception. A 2014 study concluded that metformin should be seriously considered as a first-line treatment for infertility caused by ovaries that don’t release eggs.
May Increase Births When Combined with Other Drugs
Your doctor may prescribe other medications to take alongside metformin. For example, clomiphene and follicle stimulating hormone (FSH) may be suggested to induce ovulation. A 2017 study suggested that taking metformin with FSH injections may increase live birth rates. However, the authors noted that the evidence was low-quality and more research is needed.
May Reduce Risk of Miscarriage and Preterm Birth
A 2018 study showed that PCOS patients had fewer late miscarriages and premature births if they took metformin. PCOS raises the risk of complications such as preterm birth and miscarriage. Out of 211 women who took metformin, only 9 experienced miscarriage or preterm birth. This is compared to 23 out of 223 women who had complications and did not take metformin.
Reduces Risk of OHSS
Ovarian Hyperstimulation Syndrome (OHSS) is a complication people can experience while taking injectable hormone medication. It can cause painful and swelled ovaries. OHSS is more common in people with PCOS. Evidence shows that metformin in PCOS patients can reduce the risk of OHSS if they’re at high risk for the condition and are taking gonadotropins for IVF.
May Reduce Weight Gain
As discussed above, there’s some evidence that metformin can reduce weight gain. For this reason, the drug may be prescribed to pregnant patients who are classified as overweight or obese. It’s also may be considered for PCOS patients who experience weight gain and metabolism problems.
The drug may reduce glucose production and improve glucose uptake. Some believe that this may improve the overall metabolism, which reduces the risk of negative pregnancy outcomes associated with obesity. However, there’s not enough evidence to confirm these benefits. A review of research concluded that there’s insufficient evidence to use metformin for obesity during pregnancy. More research is needed to understand how the drug affects weight.
May Benefit Clomiphene-Resistant Patients
Some people are resistant to the fertility drug clomiphene. According to some research, if clomiphene doesn’t work, doctors can consider using metformin alone or in combination with clomiphene.
Does Metformin for Fertility Work?
We’ve outlined the possible benefits of metformin for fertility. While there’s evidence to support its use, there’s also evidence it may not be effective. For example, a 2010 study concluded that metformin didn’t increase pregnancy or live birth rates. Other research suggests that metformin for fertility is effective but shouldn’t be used as a first treatment since clomiphene and letrozole are more effective.
Some studies suggest that metformin in PCOS may decrease OHSS, but doesn’t raise the overall pregnancy rate.
When looking at the documented benefits as a whole, it appears metformin may work—but only in certain cases. Research suggests that metformin for fertility is only effective for specific people. This includes people with PCOS who are:
- Obese
- Have impaired glucose tolerance
- Have type 2 diabetes
- Are clomiphene-resistant
There’s some evidence that stopping metformin abruptly once pregnant may heighten the risk of pregnancy loss. For this reason, some researchers suggest that patients continue taking metformin through the first trimester.
Taking all this into consideration, is metformin in PCOS your best option? Your doctor should weigh the pros and cons of metformin with similar drugs. If they think your condition could benefit from metformin for fertility, they may prescribe it alone or alongside another medication.
Side Effects of Metformin with PCOS
Taking metformin for fertility can cause side effects such as:
- Nausea
- Vomiting
- Abdominal pain
- Diarrhea
- Dizziness
- Tiredness
According to research, these symptoms can vary in intensity, and in most cases, the symptoms go away. Evidence suggests that side effect severity can be reduced by gradually increasing the dose until the ideal dose is reached. Taking metformin in PCOS with a meal can also help manage symptoms.
If you’ve been prescribed metformin for fertility, make sure to communicate side effects with your doctor so they can help manage your symptoms.
Other Fertility Aids for Women
If you’re having trouble ovulating, your doctor may compare the benefits of metformin for fertility with other medication options. To learn about another fertility drug for ovulation, read Full Guide on Letrozole Fertility Drug Side Effects, Cycles + More.
Other medical fertility aids for women include:
- Fertility injections
- Fertility medication for men (if infertility is caused by a male factor)
- In vitro fertilization (IVF)
- Intrauterine Insemination (IUI)
- Surgery (if specific issues are causing infertility)
- Third-party reproduction
Aside from medical solutions, your doctor may also recommend lifestyle changes, like:
- Quitting medications that reduce fertility (always talk to your doctor first)
- Cutting back or stopping drinking or drug use
- Improving physical health
- Improving mental health
- Finding your fertility window
For a full guide on fertility solutions, read Increasing Fertility: 11 Fertility Aids for Women + Men That Work.
Summary: Metformin for Fertility in PCOS Patients
Metformin is used off-label to help induce ovulation in PCOS patients. More evidence is needed to understand the effectiveness of the drug and why it may work. Current research suggests that metformin can induce ovulation and result in better pregnancy rates in specific groups of people. If you have PCOS and you’re obese, have type 2 diabetes or impaired glucose tolerance, metformin may be a good option. Talk with your doctor about the risks and benefits of metformin versus other drugs for fertility.
P.S. Do you have a pocket fetal doppler ready for when you successfully conceive? These handheld devices allow you to listen to your baby’s heartbeat while she’s inside your womb! They provide reassurance and create meaningful bonding for the whole family.
