Does Metformin Cause Hair Loss? What You Need to Know

If you’re managing type 2 diabetes with metformin, you might have concerns about potential hair-related side effects. So, does metformin cause hair loss? 

Some people do report hair thinning while on this medication, it’s not a guaranteed side effect.  

Below, we cover how metformin works, what the research says about metformin and hair loss, and how to treat hair thinning — whether it’s metformin-related or not.

Before we get into whether metformin causes hair loss, here’s a quick rundown on how metformin works. 

Metformin is a prescription medication that treats high blood sugar in people with type 2 diabetes who are insulin-resistant. It’s in a class of drugs known as biguanides. Healthcare professionals sometimes prescribe it off-label for weight loss or polycystic ovary syndrome (PCOS). It’s not a treatment for type 1 diabetes. 

Metformin works by decreasing the amount of glucose your body absorbs from food and reducing the amount of glucose your liver makes. This helps control your overall blood glucose. 

The drug can also increase your body’s sensitivity to insulin, which helps regulate blood sugar levels.

Metformin doesn’t directly cause hair loss, but the conditions it treats, like type 2 diabetes and PCOS, might. 

Studies also show that taking metformin can lead to vitamin B12 deficiency. And guess what? Your body needs this nutrient for healthy hair growth. 

Below, we go into more detail about these indirect causes of metformin hair loss.

Diabetes and Hair Loss

Diabetes is a serious health condition where the body struggles to control blood sugar and becomes resistant to insulin. Left untreated, it can lead to severe complications, including death. 

Studies suggest that there’s a link between diabetes and hair loss.

A small study of 100 men in India found that androgenetic alopecia (AKA male pattern baldness) might be an early warning sign of metabolic syndrome, which may increase your risk of type 2 diabetes and other health conditions like heart health issues.

A larger study with over 7,000 participants also concluded that male pattern hair loss could be a predictor of diabetes and heart disease. Researchers noted that participants with moderate to severe male pattern hair loss had a “significantly higher” risk of death from diabetes.

Additionally, hair loss on the legs could indicate peripheral artery disease in people with type 2 diabetes. 

Learn more about diabetes and hair loss in our blog.

Metformin and Vitamin B12

B12 deficiency can cause a host of symptoms, including:

• Muscle weakness

• Weight loss

• Constipation

• Hair loss

But here’s the thing: Unless you’re vegetarian or vegan, vitamin B12 is pretty uncommon.

Most people get enough through foods like fish, eggs, milk, and meat, and it’s easy to top up your levels with supplementation. 

But metformin can mess with your body’s ability to absorb vitamin B12, contributing to hair thinning or an interrupted hair growth cycle. 

Metformin and PCOS

PCOS is a hormone disorder affecting some women and people with ovaries. 

It leads to the formation of ovarian cysts that produce excess androgens (AKA male hormones).  

Research shows that 20 to 30 percent of people with PCOS also have female pattern hair loss.

So if you’re taking metformin off-label for PCOS, your condition could be triggering excess shedding. 

Other Potential Causes of Hair Loss

Some medications can make you shed more than usual, but they’re not the only hair loss culprits.

If you’re taking metformin and noticing hair loss, it might be due to something other than the medication. 

Male pattern baldness is a genetic form of hair loss that affects up to 50 percent of men by age of 50.

Aside from diabetes, various health conditions can also trigger thinning and hair fall, including:

• Nutritional deficiencies

• Hormonal imbalances

• Fungal infections

• High blood sugar 

• Trichotillomania (compulsive hair-pulling)

• Cancer

• Alopecia areata, an autoimmune disease

• Extreme physical or emotional stress (AKA telogen effluvium)

Learn more about the health conditions that can cause hair loss in our blog.

What about metformin hair growth? Could it actually help with hair loss?

A 2022 animal study found that metformin might increase hair follicle regeneration, but it hasn’t been tested in humans yet. 

Evidence from a 2023 study suggests that topical metformin could help treat alopecia areata, an autoimmune disease that causes patchy hair loss.

Is hair loss a side effect of metformin? No. Metformin doesn’t directly cause hair loss, but it can cause other side effects. 

According to the U.S. Food and Drug Administration (FDA), the most common adverse reactions include:

• Diarrhea

• Nausea

• Gas

• Indigestion

• Stomach discomfort

• Headache

• Weakness

A rare but serious side effect of metformin is lactic acidosis, when lactic acid builds up in the body. It can be fatal, and its early signs, like abdominal pain, feeling unwell, and breathing troubles, can be easy to overlook.

If you experience any side effects when taking metformin, talk to your healthcare provider. 

A Side Note on Metformin Safety Recalls

Several manufacturers have recalled their metformin hydrochloride due to potentially high levels of a cancer-causing ingredient. 

This ingredient, nitrosodimethylamine (NDMA), might be present in some extended-release formulas above safe limits. 

As of early 2021, at least 13 drug companies have recalled their extended-release formulas. If you’re taking metformin extended-release, it’s a good idea to check in with your healthcare provider.

Noticing hair thinning? Your best bet is to talk to a healthcare professional about your hair loss treatment options. The good news is that the most common form of hair loss, male pattern baldness, is treatable. 

Below, we outline some of the most effective options for addressing hair loss. 

Hair Loss Medications

Minoxidil and finasteride are two of the most effective hair loss medications available. They’re also the only FDA-approved hair loss drugs out there today. 

Topical minoxidil treats hair loss by stimulating hair growth. As a vasodilator, it widens blood vessels to encourage blood flow to the scalp. It also prolongs the anagen, or growth, phase of the hair growth cycle. Bonus: It’s available without a prescription. 

You’ll need a prescription for oral minoxidil, though, which doctors sometimes prescribe off-label for hair loss.

Finasteride is a once-daily pill that prevents testosterone from converting to dihydrotestosterone (DHT), a hormone known to trigger hair loss. It’s a good choice for treating male pattern baldness, but won’t work to reverse hair loss resulting from medication use or non-hormone-related health conditions. 

Hims offers finasteride medication (following a consult with one of our healthcare providers), as well as minoxidil foam, minoxidil liquid solution, and minoxidil chewables (following a consult).  

We also carry a combination topical treatment, a two-in-one finasteride & minoxidil spray.

Need an extra hair boost? Try our biotin gummies for hair growth, DHT-blocking saw palmetto shampoo, volumizing shampoo, and conditioner.

Managing Related Health Conditions

If you have diabetes, it’s important to speak to a healthcare professional about your diabetes treatment options. Treating your condition and managing blood sugar can help you avoid diabetes-related hair loss. 

A medical professional or dermatology expert can also rule out other potential causes of hair loss that have nothing to do with your condition, like a hormone imbalance or immune health issue.

It’s normal to worry about side effects like hair loss when taking medication. But metformin doesn’t usually trigger hair loss. 

Let’s recap what we know about metformin and hair loss:

• Metformin doesn’t cause hair loss, but the conditions it treats might play a role. Hair loss can happen with type 2 diabetes and PCOS. 

• Hair loss could be an early sign of type 2 diabetes. Losing hair follicles could be a warning sign of health problems down the road, which is why it’s so important to talk to a healthcare professional if you’re experiencing hair thinning. 

• Treatments for hair loss are available. Medications like minoxidil and finasteride are proven to help slow or stop hair loss. 

Talking with a healthcare provider about your condition and which treatment options might be right for you is a good first step.

Looking to take metformin for weight loss? Start a consultation with a licensed healthcare provider today!