Methotrexate is a commonly used disease-modifying antirheumatic drug (DMARD) for rheumatoid arthritis (RA), a type of inflammatory arthritis. Some people on myRAteam, the online support network for people with RA, have asked about the different side effects of taking methotrexate, and whether changes in body odor are a known side effect.

“Anybody have a different body odor with MTX [methotrexate]?” asked one member.

Although methotrexate does present a range of possible side effects, researchers have not found changes or increases in body odor to be one of them. Changes in body odor that occur while taking methotrexate could be due to other side effects of the medication, however. Additionally, the drug can potentially alter one’s sense of smell, which could lead to a perceived change in body odor.

This article will discuss ways in which methotrexate use might change your body odor, other factors that affect body odor, and ways to prevent and treat body odor.

Methotrexate and Body Odor

According to the Arthritis Foundation, methotrexate is a popular first-line treatment for RA. It helps slow RA disease activity and joint damage, and it addresses other symptoms of RA like joint pain and swelling.

The most common side effects of methotrexate include gastrointestinal problems like nausea and vomiting. Less common side effects include mouth sores, dry mouth, hair loss, shortness of breath, headaches, and fatigue.

Although changes in body odor are not known side effects of methotrexate, other side effects could affect a person’s usual body scent — or how they perceive it.

Sweating

Although not common, sweating is a possible side effect of methotrexate. Sweating has also been reported as a general symptom of RA.

Because body odor is produced by the mixture of sweat and bacteria on your skin, increased sweating could cause someone’s body scent to change.

Liver Function

Another way that body odor could be related to methotrexate use is through changes in liver function. Liver damage or disease is a rare but more serious side effect of methotrexate use.

Researchers have found liver disease can be associated with changes in body odor. With liver disease, your body odor may start to smell like bleach due to the build-up of toxins in your body.

When taking methotrexate, your doctor will order regular blood tests that will monitor the functioning of your liver and other organs. A change in body odor while taking methotrexate may have nothing to do with your liver. If you are worried about your liver function, talk to your rheumatology care provider.

Altered Sense of Smell

Sometimes, medications and medical conditions can affect your sense of smell. Methotrexate is one such medication, according to the American Academy of Family Physicians. However, it’s unclear how many people who take methotrexate experience this effect.

Therefore, if you notice a change in your body odor while taking methotrexate, it could be due to a change in your sense of smell, rather than an actual change in your body odor.

Notably, your sense of smell can decrease or change throughout life for several other reasons. With aging, and especially after age 60, some loss of smell and taste is normal. Other factors that may contribute to a change or loss of smell include viral infections like COVID-19, cigarette smoking, nasal or sinus problems, or head or facial injuries.

Some medical conditions like Alzheimer’s disease or Parkinson’s disease might affect the sense of smell through their effects on the nervous system. Medications like angiotensin-converting enzyme (ACE) inhibitors and beta-blockers can cause loss of smell or taste.

Some nutritional deficiencies (e.g., low vitamins, low zinc, low copper) may also affect your sense of smell.

What Causes Body Odor?

Body odor is created when the contents of your sweat (like water, salt, and fat) mix with the bacteria on your skin. This mixture can give off an odor that smells sour, sweet, or tangy — or has no smell at all.

Increased or excessive sweating might cause more noticeable body odor. Although sweat alone doesn’t have any smell, sweat mixed with the bacteria on your skin will produce body odor. Increases in sweat production — whether caused by a new exercise regimen, medical condition, or medication — can increase body odor.

Different lifestyle and environmental factors determine someone’s regular body odor. Going through puberty, diet, changes in hormones, medications, and different medical conditions can all have an effect on the bacteria on the skin.

Other common factors that can affect body odor include:

• Exercise
• Genetics
• Higher quantities of body hair
• Overweightedness or obesity
• Stress
• Hot weather

For some people, body odor might stay constant throughout their lives whereas others may experience changes. Some factors that may cause changes in your body scent include medications and medical conditions.

Medical Conditions

Some medical conditions can create changes in a person’s usual body odor. These include:

• Diabetes
• Gout
• Hyperhidrosis (excessive sweating condition)
• Hyperthyroidism (overactive thyroid)
• Infectious diseases like bacterial skin diseases
• Kidney problems and disease
• Liver problems and disease

Diseases like diabetes can also produce changes in the smell of your breath. Fruity-scented breath is a sign of diabetic ketoacidosis, which occurs when your body can’t produce enough insulin. If you have diabetes and experience sudden symptoms like fruity-scented breath accompanied by very high blood glucose levels, call your doctor immediately.

Medications

Like methotrexate, other medications can affect how much you sweat, which in turn might change your body odor indirectly. Some of these medications include:

• Acetylcholinesterase inhibitors, for dementia or Parkinson’s disease
• Antivirals
• Corticosteroids like prednisone
• Diabetic medications
• Nonsteroidal anti-inflammatory drugs (NSAIDs) like naproxen
• Selective serotonin reuptake inhibitors
• Thyroid medications
• Tricyclic antidepressants

If You Suspect Body Odor Changes

If you think you may be experiencing body odor changes, as opposed to a change in your sense of smell, consider getting a second opinion from a trusted friend or family member. They can help you determine whether you smell different.

If you’re concerned about any body odor changes, reach out to your health care provider for medical advice. They can help you figure out what’s causing it and determine ways to manage it.

Always talk to your rheumatologist before making any changes to your medications, diet, or personal habits. Don’t stop taking methotrexate without their advice. The sudden discontinuation of any medications may result in serious health problems.

Tips for Managing Body Odor

Although changes in your body odor may be bothersome, there are different ways to manage it at home. Following are some general tips to prevent and manage body odor:

• Shower at least a few times per week to remove odor-causing bacteria from your skin.
• Use antibacterial soap or a benzoyl peroxide cleanser to wash bacteria from your skin.
• Shave your armpits so that sweat can evaporate more quickly and not mix with bacteria.
• Use antiperspirant and deodorant.
• Wear breathable clothing, like cotton, silk, or wool for everyday use.
• Wear moisture-wicking fabrics, such as polyester or nylon, while exercising
• Wash clothes after each use.
• Consume less food and beverages that may worsen your body odor, like garlic, onions, and alcohol.
• Find ways to manage your stress.

Treating Body Odor

If at-home strategies aren’t effective at managing your body odor, there are medical options to consider. Your doctor will work with you to find the best treatment option.

Some medical options for treating body odor issues include:

• Antibiotics, which can help decrease the amount of skin bacteria
• Prescription anticholinergics, like glycopyrrolate, which can have a drying effect on your skin
• Botulinum toxin (Botox) injections into the armpits to inhibit sweating
• Surgery to remove sweat glands or to prevent sweat glands from receiving nerve signals
• A device that has electromagnetic waves to destroy your underarm sweat glands

Talk With Others Who Understand

Living with RA can be challenging, but you don’t have to go through it alone. When you join myRAteam, you’ll gain a community of more than 193,000 people coming together to ask questions, offer advice and support, and share stories with others who understand life with RA.

Have you experienced changes in your body odor or sense of smell while taking methotrexate? How do you manage these conditions? Share your experiences and tips in the comments below or by posting on myRAteam.