What Medications Cause Strange Body Odor?

October 16, 2025 •

5 min read

Excessive sweating, or hyperhidrosis, is a known side effect of over 400 medications, and this increased perspiration can often contribute to a strange body odor. Understanding what medications cause strange body odor is the first step toward finding a solution to this potentially embarrassing issue.

Quick Summary

Many medications alter body odor by increasing sweating, disrupting skin bacteria, or releasing strong-smelling compounds. Culprits include antidepressants, opioids, and antibiotics, among others, and addressing the issue often involves a careful conversation with your doctor about your prescription.

Key Points

Hyperhidrosis: Many drugs, like antidepressants and stimulants, increase sweating, which can lead to body odor as sweat interacts with skin bacteria.
Microbial Changes: Antibiotics can disrupt the natural balance of skin and gut bacteria, potentially altering body odor and scent perception.
Direct Odor: Some medications, including lithium and bisphosphonates, have strong inherent smells or release odorous metabolic compounds that can emanate from the body.
Urinary Odor: Certain drugs, such as sulfonamide antibiotics and diabetes medications, can cause foul-smelling urine due to metabolic byproducts.
Phantom Smells: A few medications can alter a person's sense of smell, creating the perception of body odor when none exists.
Management: Never stop medication suddenly. Talk to a doctor about potential dosage adjustments, alternative drugs, or other management techniques.

The Link Between Medications and Body Odor

Body odor is a natural phenomenon caused when bacteria on the skin break down sweat into odorous compounds. While sweat itself is mostly odorless, anything that alters its composition or volume, or changes the skin's bacterial environment, can result in a different smell. Medications can influence body odor through several primary mechanisms, including excessive sweating, altering the skin's microflora, releasing strong-smelling metabolic byproducts, and in rare cases, causing the perception of an odor that doesn't exist.

Medications That Cause Increased Sweating (Hyperhidrosis)

One of the most common reasons for a change in body odor is drug-induced hyperhidrosis, or excessive sweating. When the amount of sweat increases, it provides more food for the skin's bacteria, leading to a more pronounced or different smell. Some classes of medication frequently associated with this side effect include:

Antidepressants: A wide range of antidepressants, including SSRIs (fluoxetine, paroxetine), SNRIs (venlafaxine), and tricyclic antidepressants (desipramine, nortriptyline), are well-known for causing excessive sweating in some users. This side effect, known as ADIES (antidepressant-induced excessive sweating), affects an estimated 4-20% of people on these medications.
Opioids: Pain medications such as tramadol, codeine, and oxycodone can cause increased sweating and are linked to changes in body odor.
ADHD Stimulants: Amphetamines and methylphenidate, used to treat ADHD, are known to increase perspiration.
Hormonal Medications: Treatments for conditions like breast cancer, including tamoxifen and leuprolide, can induce hot flashes and excessive sweating by affecting the endocrine system.
Thyroid Medications: Adjusting thyroid hormone levels with medications like levothyroxine can also lead to increased perspiration.

Drugs Affecting Skin and Gut Microflora

Antibiotics work by killing bacteria, but in doing so, they can disrupt the delicate balance of microbes on your skin and in your gut. When the normal, healthy bacteria are reduced, other types of odor-causing bacteria may flourish, leading to a change in scent. A notable example is the change in body odor and stool scent experienced by some patients taking metronidazole.

Medications with Inherent Odor or Metabolic Byproducts

Some drugs have a strong smell themselves or are metabolized into compounds that have a distinct odor and are excreted through the skin, breath, or urine.

Lithium: Used to treat bipolar disorder, lithium is one of the medications known to have a strong inherent smell that can emanate from the body.
Rheumatoid Arthritis Medications: Sulfasalazine, a drug for rheumatoid arthritis, can result in foul-smelling urine and body odor due to its sulfur content.
Diabetes Medications: Some diabetes drugs, like glyburide and metformin, can cause changes in urine smell. In cases of uncontrolled diabetes, a fruity odor on the breath or in sweat can indicate a serious condition called ketoacidosis.
Bisphosphonates: Used for osteoporosis, some bisphosphonates are also reported to have a strong smell.

Medications Causing Foul-Smelling Urine and Breath

While not technically body odor emanating from sweat, changes to urine and breath can also be a noticeable side effect of certain medications. This is often caused by the drug's metabolism and how its byproducts are excreted.

Vitamins: High doses of B vitamins, particularly thiamin and choline, can cause a strong odor in the urine.
Sulfonamide Antibiotics: This class of antibiotics can lead to a noticeable change in the smell of urine.
Chemotherapy Drugs: Certain cancer treatments can result in a range of metabolic changes that affect breath and body odor.

Medications Causing Phantom Odor Perception

A small number of drugs can cause a phantom odor perception, where a person smells an odor that isn't actually present or isn't detectable by others. This is related to the drug's effect on the nervous system and is distinct from actual body odor changes. Methotrexate, used for rheumatoid arthritis, is one such medication reported to alter the sense of smell.

A Comparison of Odor-Causing Medications


Drug Class	Examples	Primary Mechanism	Possible Odor Type
Antidepressants	Venlafaxine, Fluoxetine	Excessive sweating (hyperhidrosis) due to effects on the central nervous system.	Sweaty, musty, or intensified typical body odor.
Antibiotics	Metronidazole, Sulfonamides	Disruption of skin/gut microflora, causing overgrowth of different bacteria.	Fishy (gut), sulfurous, or otherwise altered odor.
Opioids	Tramadol, Oxycodone	Increased sweating through effects on the nervous system and neurotransmitters.	Intensified sweaty odor.
ADHD Stimulants	Amphetamines, Methylphenidate	Increased sympathetic nervous system activity leading to hyperhidrosis.	Intensified sweaty odor.
Lithium	Eskalith, Lithobid	Excretion of the drug or its metabolic compounds, which have an inherent smell.	Metallic, or strong chemical odor.

How to Address Medication-Induced Body Odor

Experiencing a change in body odor due to medication can be distressing, but there are several ways to manage the issue:

Talk to Your Doctor: Do not stop taking your medication. Instead, schedule an appointment with your healthcare provider to discuss the issue. They can determine if the odor is truly a side effect of your drug and explore potential solutions, such as adjusting the dose, switching to an alternative medication, or adding a secondary treatment.
Enhance Hygiene Routine: Use antibacterial soap to reduce the skin's bacterial load. Shower regularly, especially after sweating, and use a clinical-strength antiperspirant or deodorant to help manage perspiration.
Manage Underlying Causes: For conditions like hyperhidrosis, your doctor might recommend specific treatments, such as prescription antiperspirants, wipes, or even botulinum toxin injections for severe cases.
Adjust Diet: For drugs that cause smelly urine, staying hydrated and adjusting your intake of foods that affect body odor, like those with sulfur compounds, may help. Also, check with your doctor if adjusting vitamin intake is an option.
Be Aware of Phantom Odors: If you suspect you have a phantom odor perception, understand that the smell may not be real. Communicating this to your doctor is crucial for finding the right management strategy.

Conclusion

While a change in body odor can be an uncomfortable side effect of some medications, it is not uncommon and is often manageable. Whether caused by increased sweating, microbial changes, or metabolic byproducts, the solution usually lies in open communication with a healthcare professional. By understanding the link between specific drugs and their potential for altering your scent, you can take proactive steps to address the issue and regain your confidence without compromising your health. Always consult your doctor or pharmacist if you notice a significant or persistent change in body odor after starting a new medication. For more detailed information on specific medications, the Daily Med database from the National Library of Medicine is a comprehensive resource.

Frequently Asked Questions

Yes, many antidepressants, including SSRIs and TCAs, can cause excessive sweating, or hyperhidrosis, as a common side effect. This increase in perspiration can lead to a noticeable change in body odor.

Yes, antibiotics can change body odor by disrupting the normal balance of bacteria on the skin and in the gut. This allows other types of bacteria to flourish, which can produce different odor-causing compounds.

Lithium, used for bipolar disorder, is one of the medications with an inherent smell that can be excreted through the skin. The drug or its metabolic byproducts can cause a distinct, sometimes metallic, odor to emanate from the body.

'Phantom body odor' is when a medication alters your sense of smell, causing you to perceive an odor that isn't actually there or isn't detectable by others. This is a neurological effect rather than a change in your actual scent.

While not technically body odor from sweat, high doses of certain vitamins, particularly B vitamins, can cause a strong odor in your urine. If you are taking multivitamins and notice this, it may be the cause.

You should not stop taking your medication. Instead, consult your healthcare provider. They can help you determine the best course of action, which might include adjusting your dosage, switching to an alternative drug, or using other management techniques like clinical-strength antiperspirants.

For drug-induced body odor, the smell often resolves after the medication is discontinued. However, it is crucial to consult your doctor before making any changes to your treatment plan.

Some diabetes medications, such as glyburide, can cause changes in urine smell. Additionally, uncontrolled diabetes can lead to a sweet or fruity odor on the breath and sweat due to ketones, a sign of a serious condition requiring immediate medical attention.