Having a metallic mouth taste may be caused by medication or poor oral hygiene. It can also be an early sign of diabetes.

Diabetes is a chronic condition where the body doesn’t make enough insulin or use insulin properly. Insulin is a hormone that allows sugar to enter the body‘s cells, where it’s then used for energy.

When the body doesn’t make enough or use insulin properly, sugar accumulates in the bloodstream. This leads to high blood sugar.

Uncontrolled diabetes or high blood sugar can cause a range of problems, such as nerve damage and kidney damage. But these aren’t the only side effects of diabetes. Some people with diabetes may also develop a metallic taste in their mouth.

Here are a few causes of a metallic taste in the mouth related to diabetes.

Use of Metformin

Metformin is an oral medication commonly prescribed to treat type 2 diabetes. It reduces the amount of glucose (sugar) produced by the liver. This helps lower blood sugar levels to a safe range.

But although Metformin can stabilize blood sugar — thus reducing the risk of serious diabetes complications — some people who take this medication complain of a metallic taste in their mouth.

The reason isn’t quite clear, but this taste disturbance is likely due to the prescription drug excreting into saliva.

The good news is that this taste problem is often temporary, with taste returning to normal after 1 or 2 weeks.


Parageusia is a taste disorder that can occur alongside diabetes. It’s also known to cause a metallic taste in the mouth. But, what’s the connection between parageusia and diabetes?

Simply put, your central nervous system (CNS) affects how your brain perceives taste, and it’s possible that uncontrolled diabetes can affect your nervous system.

Prolonged high blood sugar slowly damages the nerves in your body. This can include the nerves in the:

  • eyes
  • feet
  • legs
  • arms
  • mouth

Parageusia occurs when injury or damage to the CNS distorts taste and smells. Taste disturbances — such as a metallic taste in the mouth — develop when the nerves that affect taste become damaged.

Oral health issues

Oral health issues are another common cause of a metallic taste in the mouth.

Many people think of diabetes only affects blood sugar. But too much sugar in your blood can cause problems with your mouth, too.

Periodontal disease

High blood sugar also increases the sugar level in your saliva. And if your saliva contains more sugar, you’re at a higher risk for cavities, gingivitis, and periodontitis. The latter two can cause a metallic taste in the mouth.

Diabetic tongue

Diabetic tongue is another oral health problem that can cause a metallic taste in the mouth. This occurs when a combination of too much sugar in your saliva and a dry mouth triggers oral thrush.

Thrush develops when a fungus that occurs naturally starts to grow out of control. It can affect the gums, tongue, and the roof of the mouth.

A metallic taste in your mouth due to diabetes might improve over time. It all depends on the underlying issue.

If you take the drug Metformin, a metallic taste should subside after a few weeks once your body adjusts to the medication. If taste disturbance doesn’t improve, see a medical professional.

Adjusting your dosage or finding an alternative drug might improve your taste.

If a metallic taste is due to sugar in the saliva, controlling your diabetes can also help improve your taste. Additionally, if you develop an infection due to poor dental hygiene, seeing a dentist and treating the infection might improve taste.

If taste disturbance occurs due to nerve damage, the severity of nerve damage may determine whether your taste returns to normal.

Even if you adjust your medication, improve your oral hygiene, and take steps to control your blood sugar, a metallic taste in your mouth might not improve immediately.

As you wait for your condition to improve, here are a few tips to help your food taste better:

  • Use different herbs and spices when preparing meals to add additional flavor.
  • Drink plenty of water or chew sugarless gum. This might improve a dry mouth and lessen the metallic taste in your mouth.
  • When you’re eating, use non-metallic utensils. This can also reduce a metallic taste.
  • Treat colds, sinus infections, and allergies. These conditions can worsen a metallic taste.
  • Eat your food cold. Some foods taste better at a lower temperature.

See a doctor if a metallic taste in your mouth does not improve after a couple of weeks. It’s important that you don’t ignore this taste disturbance, as it can indicate problems with blood sugar control.

If you haven’t been diagnosed with diabetes, yet you notice a metallic taste in your mouth, see a medical professional. This taste disturbance is sometimes an early sign of diabetes.

A metallic taste in your mouth can distort the taste of foods and beverages, making it difficult to enjoy your favorite foods. Although taste disturbances have different underlying causes, it’s important to see a doctor for symptoms that don’t improve.

This can be an early sign of diabetes, as well as blood sugar that is not in target range.