Metformin for PCOS:
How It Works & What to Expect

Written by Kathleen Morrison
Medically Reviewed by Andrea Sleeth WHNP-BC, MSCP

Key takeaways

• Many patients with polycystic ovary syndrome see symptom improvements with Metformin therapy, as it helps support PCOS symptoms
• Most women notice changes in symptoms within the first 3 months of taking Metformin for PCOS, with significant improvements appearing in 3-6 months for some symptoms.
• Metformin in polycystic ovary syndrome helps improve insulin sensitivity, support more regular menstrual cycles, may help improve fertility outcomes, and help with weight management, etc.
• Extended-release offers once-daily dosing with fewer side effects of Metformin, while immediate-release provides cost savings.

If you've been diagnosed with PCOS, you've probably heard about Metformin.

Metformin isn’t just a “diabetes med”; it’s often prescribed to support PCOS symptoms because it helps tackle insulin resistance, which is a major behind-the-scenes driver of symptoms associated with PCOS. These include irregular periods, weight changes, and hormonal chaos.

Basically, it helps your body respond better to insulin so your hormones can chill a little.

In this guide, we’ll break down how Metformin works for PCOS, who it’s best for, potential side effects, and what to realistically expect. No medical jargon, no scare tactics, just the facts you actually want!

Wisp treatment options are available only after consultation with a licensed medical professional. You should consult with your healthcare provider before starting a new supplement or treatment regimen. Individual results may vary.

First, what's the link between PCOS and insulin?

Polycystic ovarian syndrome affects one in ten women. And for many patients with PCOS, insulin resistance drives everything.

Here’s the chain reaction:

• Insulin’s job is to move sugar from your blood into your cells for energy.
• With PCOS, your cells don’t respond to insulin as well, so your body makes more and more insulin to compensate.
• Increased insulin levels tell your ovaries to produce more androgens (male-type hormones like testosterone).
• Higher androgens then make insulin resistance even worse.

Rinse. Repeat.

Symptoms of PCOS coupled with insulin resistance

Symptoms related to polycystic ovarian syndrome vary widely: irregular periods, excessive facial/body hair, stubborn acne, thinning scalp hair, resistant weight gain, darkened skin patches, and mood changes.

For those trying to conceive, PCOS may also cause infertility in women who aren't ovulating.

When insulin resistance steps into the picture as well, it creates some common patterns:

• Increased appetite
• Belly fat storage
• Inflammation
• Significantly higher Type 2 diabetes risk.
  

Now, what's Metformin, and how does it help?

Metformin is a prescription medication that’s been around forever (and for good reason). It was originally designed to treat type 2 diabetes, but it’s also commonly used for PCOS because it improves insulin sensitivity.

How Metformin works in your body

Metformin targets the root metabolic issue behind many PCOS symptoms: insulin resistance. Originally used for diabetes, it’s now a go-to because it helps regulate hormones at the source.

Here’s what it does:

• Helps lower glucose production in the liver
• Helps muscles absorb glucose more efficiently
• Improves overall insulin sensitivity

When insulin levels drop, the ovaries produce less testosterone. This supports more regular periods, less excess hair, and improved ovulation.

Metformin can also work directly on the ovaries, lowering hyperandrogenic symptoms of PCOS and improving follicle development.

Routine use of Metformin also helps in increasing Sex Hormone-Binding Globulin (SHBG) to reduce testosterone’s impact.

What to expect when first starting Metformin for PCOS?

Starting Metformin can feel like a lot for many women with PCOS. But knowing what to expect makes it way easier to stick it out.

Think of it as a “learning curve” med: there’s an adjustment phase, then the payoff.

Side effects to watch for (adjustment phase):

Metformin may cause mild side effects at the beginning (during the adjustment phase):

• Nausea
• Stomach upset or bloating
• Changes in bathroom habits

Totally normal. These usually fade within 2–4 weeks as your body adapts.

Tips to make it easier for you:

• Always take Metformin with food (never on an empty stomach)
• Start at the lowest dose and increase slowly, per your provider
• Ask about extended-release Metformin (it’s gentler on your stomach)
• Stay hydrated. This actually helps more than you’d think.

If side effects feel like too much, don’t tough it out. Your provider can adjust timing, dose, or formulation so this works for you.

How long does it take for Metformin to work?

Because Metformin works by improving insulin sensitivity and gently nudging hormonal balance, it can take a bit of time to see noticeable change.

Many people begin to notice early shifts in things like insulin resistance or energy levels within a few weeks, but changes in menstrual regularity and ovulation often show up around 2–3 months of consistent use.

For broader improvements in metabolic features or cycle consistency, 3–6 months (or longer) is a common timeframe clinicians reference.

Everyone’s body is different, so sticking with your prescribed plan and checking in with your provider helps tailor expectations and adjustments.

Choosing your formulation: IR vs ER

If you’re prescribed Metformin therapy, you’ll usually pick between immediate-release (IR) and extended-release (ER).* Options through Wisp are extended release only.

Same medication, different vibe. Knowing the difference makes choosing way less stressful.

Immediate-Release (IR) Metformin

• Absorbs quickly, so it’s taken 2–3 times a day with meals
• Lower cost and often better insurance coverage*
• Faster absorption can mean more noticeable GI side effects at first (bloating, nausea, bathroom urgency)
• Side effects usually ease over time, but the beginning can be… spicy
• Works well if you’re okay with multiple doses and can ride out early side effects

Extended-Release (ER) Metformin

• Dissolves slowly over 24 hours
• Once-daily dosing, usually with dinner
• Much gentler on the stomach—no sudden spike
• Often preferred for long-term PCOS management
• Slightly higher cost, but many find it worth it for better tolerability

Both are equally effective when used to support PCOS symptoms. The real difference is tolerability and convenience. Providers factor in symptoms, lifestyle, and sensitivity.

But truly, the best Metformin for polycystic ovary syndrome is the one you’ll take consistently.

*Wisp offers a 500mg oral tablet, extended-release (ER), to help manage PCOS symptoms. Treatment starts at $24. Wisp does not accept insurance.

Is Metformin a GLP-1? Should you be concerned?

This comes up constantly. Both Metformin and GLP-1 get buzz for weight management, but Metformin and GLP-1s are completely different.

Metformin has been used off-label since the 1950s for weight management with decades of safety data. Agents such as Metformin reduce liver glucose production and improve cellular insulin sensitivity.

GLP-1s, like Ozempic (also used off-label for weight loss), on the other hand, mimic gut hormones. They aim to slow digestion, increase fullness, and regulate blood sugar.

GLP-1s are newer, primarily for diabetes and weight loss, and sometimes prescribed off-label for PCOS.

While GLP-1s achieve more dramatic weight loss in obese women, they cost way more, and have less long-term data for the treatment of polycystic ovary syndrome.

Research on whether semaglutide is more effective than Metformin or superior to Metformin for PCOS support continues. But Metformin remains first-line with proven effectiveness, safety, and affordability.

Metformin for fertility and pregnancy

If you’re trying to conceive and have PCOS, Metformin might help.

Since women with polycystic ovaries often face anovulatory infertility (aka no ovulation, no pregnancy), addressing the root issue matters.

That’s where Metformin in the treatment plan comes in.

How does Metformin support fertility treatment?

Metformin targets the metabolic dysfunction related to polycystic ovary syndrome that blocks normal ovulation. Many women start seeing ovulatory patterns return within a few months.

For women doing IUI or IVF, Metformin may also improve egg quality and embryo development, which matters more than people realize.

Metformin during pregnancy

The benefits of Metformin don’t stop at conception. Its use in PCOS during pregnancy is well-studied, with thousands of pregnancies showing no increased risk of birth defects.

Providers may also prescribe Metformin to reduce the risk of gestational diabetes. The risk is higher in women with polycystic ovary syndrome coupled with insulin resistance and glucose dysregulation.

But a fraction of studies also show that it may cause low birth weight, increased childhood obesity, and insulin resistance. It’s important to note that the available research is limited and observational. More high-quality studies are needed to fully understand these potential risks.

And, because fertility goals, pregnancy status, metabolic health, and overall risk factors look different for everyone, there’s no one-size-fits-all answer here. A qualified healthcare provider can help assess your specific situation and determine whether Metformin makes sense for you.

Wisp does not treat or prescribe Metformin for individuals who are actively trying to conceive or who are pregnant. Any use of Metformin in these situations should be managed by an in-person healthcare provider for safety.

Let's make PCOS a little less complicated

Managing PCOS can feel overwhelming, but understanding where Metformin fits into the picture makes everything a lot clearer. Metformin plays a key role in improving insulin resistance, which can help regulate cycles, support ovulation, and benefit overall metabolic health.

Translation: it works behind the scenes to help your hormones get back into balance.

That said, PCOS treatment isn’t one-size-fits-all. Finding the right dose, or choosing between IR vs. ER Metformin, can take a little trial and error. That’s normal. What matters most is consistency and working with a provider who actually understands PCOS.

Wisp makes it easy to connect with licensed providers who get PCOS because managing your health shouldn’t be complicated. It should feel doable, supportive, and totally on your terms.

No in-person waiting rooms, no awkward conversations!

This blog post is for informational and educational purposes only and should not be taken as professional advice. Always consult with a qualified professional before making any decisions based on the information provided here.