Metformin is a medication that is commonly prescribed to treat type 2 diabetes mellitus, polycystic ovary syndrome (PCOS), and insulin resistance.
Some people have concerns that metformin can cause hair loss, though there is not much evidence to prove that’s true. Instead, hair loss in people who take metformin is likely caused by something else.
In this article, we’ll explore hair loss causes related to diabetes, common side effects of metformin, and how to address hair loss if it happens.
Does Metformin Cause Hair Loss?
There is no substantial scientific research that shows that metformin causes hair loss. Metformin has been used to treat diabetes since 1957 and has been used in the United States since 1995.
During that time, there have only been a few reports of hair loss in people who were taking metformin.
The U.S. Food and Drug Administration (FDA) data does not list hair loss as any possible side effect or problem associated with metformin.
One report from 2017 noted the loss of eyebrows and eyelashes in a patient taking metformin and another diabetes drug, sitagliptin.
While metformin may have contributed, it is not possible to know that for sure since other medications and unknown factors were also involved.
In contrast, a 2016 clinical trial involving 56 people who had PCOS found that metformin actually decreased hair loss.
It is not impossible that metformin could contribute to hair loss, but from the evidence we have, it is more likely that hair loss in people taking metformin is caused by other factors.
Diabetes and Hair Loss
There are many ways that diabetes can contribute to hair loss.
High levels of blood glucose can cause blood vessel damage.
Hair relies on the transport of oxygen and nutrients via blood vessels, so if there is any damage, it may be harder to get nutrients to all parts of the body, such as the hair follicles.
Hair may fall out more frequently or may grow back slowly.
Insulin resistance is another factor in diabetes that may affect hair health.
People who have type 2 diabetes usually have elevated glucose because there is a decreased response to insulin.
Research from 2014 found an association between insulin resistance, metabolic syndrome, and hair loss from a condition called alopecia.
Some possible long-term side effects of taking metformin are vitamin B12 deficiency and anemia. Both of these conditions can lead to hair loss, which could mean that metformin contributes in a roundabout way.
However, not everyone who takes metformin will experience these side effects, so it could also be a coincidence.
Common Metformin Side Effects
Metformin can cause some common side effects. They include:
- Diarrhea: Metformin increases the absorption of glucose in the intestines which can irritate the lining of the gut, and trigger gastrointestinal upset and diarrhea. This is typically short-lived and can be improved by taking metformin with meals.
- Nausea: Metformin changes the way that the liver makes glucose, which can cause nausea until your body is used to the medicine.
- Weight loss: Metformin is not a weight loss drug, but because it improves the way that the body responds to glucose and insulin, it can lead to less fat storage and more fat loss.
- Headache: Metformin works by preventing glucose production in the liver, and until your body is used to this change, mild headaches may occur. Tell your healthcare provider if headaches last a long time or get worse.
- Metallic taste in mouth: Around 3 in every 100 people taking metformin may notice a temporary metallic or bad taste in the mouth. This effect usually only lasts for a few days.
Related Causes for Hair Loss
Hair loss can happen for many reasons. Even if you are taking metformin, there may be related causes that are triggering hair loss.
Possible hair loss causes include:
- PCOS can lead to higher levels of androgen hormones which can be associated with more hair on the face and may lead to thinning hair or hair loss on the head.
- High blood sugar levels can damage blood vessels, which may make it harder for hair to get the nutrients it needs to be healthy.
- Stress can impact the body in many ways, including temporary hair loss. Living with a long-term chronic condition like diabetes or PCOS can be stressful, but so can many other life factors. Stress can also make it harder to stick to a healthy diet, lifestyle, and exercise plan.
Remedies for Hair Loss
If you have experienced hair loss, it can be stressful or frustrating.
But there are ways that you can care for your hair and address the underlying causes and visible signs of this symptom.
- Check for nutrient deficiencies: While specific nutrients are not tied to hair loss, healthy hair requires adequate amounts of vitamins and minerals. If dietary intake is inadequate, or digestive function is compromised, the body may be missing basic nutrients to support healthy hair.
- Consider hair loss treatment: Certain medications like minoxidil (Rogaine) can be used to increase hair growth. It takes time to work, requiring daily treatment for at least 6 months. But this can be an effective approach for more severe hair loss.
- Reduce stress: While this is easier said than done, some research shows that there is a potential link between stress and short-term changes to hair growth.
- Be gentle with your hair: Roughly brushing, washing, or styling hair may lead to more hair breakage or loss. If hair is already thin or there are other conditions contributing to hair loss, not being gentle can make the loss seem worse.
When to See a Medical Provider
People who notice sudden hair loss should see a healthcare provider.
If you notice increased hair loss over a short period of time, such as a few weeks or months, you should let a healthcare provider know.
Hair loss can be caused by many things, but your medical provider will likely run a few basic lab tests to check for imbalances such as:
- Thyroid hormones
- Blood glucose levels
- Signs of infection
If you take medications, your healthcare provider will also consider whether hair loss is a known side effect.
A medical provider will recommend treatments, natural remedies, or other approaches to help address hair loss.
Frequently Asked Questions
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Metformin: Historical overview. (2017).
Glucophage (metformin hydrochloride) tablets. (2017).
Loss of Eyebrows and Eyelashes During Concomitant Treatment with Sitagliptin and Metformin. (2017).
Comparison clinical and metabolic effects of metformin and pioglitazone in polycystic ovary syndrome. (2016).
Androgenetic alopecia, metabolic syndrome, and insulin resistance: Is there any association? A case–control study. (2014).
Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study. (2016).
Polycystic ovarian syndrome in patients with hair thinning. (2020).
HAIR FOLLICLE CHARACTERISTICS AS EARLY MARKER OF TYPE 2 DIABETES. (2016).
Stress and the Hair Follicle. (2003).
The Role of Vitamins and Minerals in Hair Loss: A Review. (2019).
Hair and stress: A pilot study of hair and cytokine balance alteration in healthy young women under major exam stress. (2017).