Should You Try Metformin for Fertility?

Metformin is a common prescription drug for people with PCOS or insulin resistance. It helps lower insulin levels, which can reduce testosterone and make ovulation more regular. Some studies show it can slightly improve fertility outcomes, especially when combined with other medications like letrozole or Clomid, but it’s not a fix-all.

If your insulin levels are normal and your cycles are regular, metformin probably won’t help and might cause more trouble than it’s worth. The side effects, mainly nausea, cramping, and diarrhea, can be rough. Still, in certain IVF situations where egg quality is a concern, some doctors might prescribe it off-label (meaning it's not officially approved for fertility but can still be used based on clinical judgment).

Metformin is for people with PCOS + insulin resistance

Metformin has been studied in a few different fertility contexts, mostly focused on people with PCOS. Here's what the research shows:

1. It helps with ovulation in PCOS. A 2020 meta-analysis found that metformin increased ovulation rates in people with PCOS, especially when combined with Clomid or letrozole. On its own, it was slightly less effective than those drugs, but still better than placebo. It’s not the strongest ovulation inducer out there, but it can help, especially if you have insulin resistance.

2. It may improve egg quality in some IVF patients. A 2021 study looked at people with PCOS undergoing IVF. Those who took metformin had better-quality embryos and slightly higher pregnancy rates. This doesn’t mean everyone should take it for egg quality, these were people with clear insulin or hormone imbalances.

3. Not effective for people without PCOS. A 2017 review found that in people without PCOS, metformin didn’t make a meaningful difference in fertility outcomes. If you don’t have PCOS or insulin issues, science doesn’t back using it.

   
   

So far, the clearest evidence is for people with PCOS + insulin resistance, especially if they’re not ovulating on their own or are preparing for IVF. For everyone else, the benefits are uncertain, and the side effects are real.

Side Effects of Metformin

Metformin’s side effects are one of the biggest reasons people hesitate to try it. While the benefits can be worth it for some, the side effects can be tough, especially at the beginning. 

Digestive issues are the most common complaint. Expect nausea, diarrhea, stomach cramps, and bloating, especially in the first few weeks. This happens because metformin affects how your body processes sugar and can irritate the gut. Starting with a low dose and taking it with food can help reduce some of these symptoms.

Vitamin B12 deficiency is another concern if you take metformin long-term. Some studies suggest that metformin can interfere with how your body absorbs B12, which is essential for nerve function and red blood cell production. If you’re on metformin for a while, ask your doctor about B12 supplements or testing your levels.

Lactic acidosis (rare but serious) is a potential risk. This happens when there’s too much lactic acid in the blood, which can be life-threatening. However, it’s extremely rare and mostly affects people with kidney problems or other serious health issues. Make sure your doctor knows if you have any kidney problems before starting metformin.

Weight loss is a possible (but not guaranteed) side effect. For some people, metformin can lead to a slight drop in weight because it helps balance blood sugar and insulin levels.

There Are Many Other Alternatives

Metformin isn’t the only option when it comes to improving fertility. If you’re looking for alternatives, there are plenty of options that are effective, and many of them come with fewer side effects.

• Inositol is a popular choice for improving insulin sensitivity, especially for those with PCOS. It helps regulate hormones, improve egg quality, and support ovulation without the gut issues that come with metformin.

• Lifestyle changes like healthy eating, regular exercise, and weight management can go a long way in improving fertility, especially for those with insulin resistance or PCOS.

• Vitex (Chaste Tree Berry) is an herbal remedy used to balance hormones and promote regular ovulation, especially for those without insulin resistance.

• N-Acetyl Cysteine (NAC) has shown promising results in improving ovulation and egg quality, especially in women with PCOS.

• Acupuncture can help reduce stress, improve circulation to the ovaries, and regulate menstrual cycles, which may enhance fertility.

• L-carnitine, an amino acid, can help with insulin sensitivity and support better egg quality, particularly in those with metabolic issues.

  
  

There are many paths to improve your fertility, whether through supplements, lifestyle changes, or natural therapies. The best option for you depends on your unique needs and health history.

Download the Lume App to Find Out What Works for You

Everyone’s fertility journey is different, and it’s important to find what works best for your body. The Lume app, available on iOS and Android, can help you assess your fertility readiness and give you a personalized list of supplements and lifestyle changes to make. Whether you’re just starting to learn about your body’s fertility signals or you’re looking to optimize your chances, the Lume app is here to guide you every step of the way.