What medications make you smell weird?: A Guide to Drug-Induced Body Odor

October 11, 2025 •

4 min read

According to the National Library of Medicine, hundreds of medications list body odor or excessive sweating as a possible side effect, leaving many patients to wonder, 'What medications make you smell weird?'. This phenomenon, while often surprising, is a documented and manageable consequence of how some drugs interact with your body's natural processes.

Quick Summary

Several classes of drugs can cause changes in body odor through various mechanisms, including excessive sweating, altered metabolism, and the excretion of aromatic compounds. Common culprits include antidepressants, diabetes medication like metformin, and certain antibiotics. Management strategies exist, but it is important to consult a doctor before changing your prescription.

Key Points

Excessive Sweating: Many medications, including antidepressants and opioids, increase sweat production, which can lead to more noticeable body odor.
Metabolic Changes: Some drugs alter the body's metabolism or release odorous compounds, which are then excreted through sweat or breath.
Fishy Smell: Metformin, a diabetes drug, can cause a distinct fishy odor, while B-complex supplements can cause a similar issue for individuals with trimethylaminuria.
Metallic Taste/Bad Breath: Antibiotics and certain psychiatric medications can cause dry mouth and alter oral bacteria, leading to bad breath or a metallic taste.
Management Strategies: Options for managing medication-induced odor include using antibacterial soaps, stronger antiperspirants, and wearing breathable clothing.
Professional Consultation is Key: Never stop a prescribed medication because of a side effect without first consulting your doctor or pharmacist for guidance on alternatives.

How Medications Alter Body Odor

Body odor is created when sweat, which is normally odorless, is broken down by the bacteria on your skin. Medications can interfere with this process in several ways, leading to an unusual smell. Understanding these mechanisms is the first step toward finding a solution.

Excessive Sweating (Hyperhidrosis)

One of the most common reasons for drug-induced odor is excessive sweating, or hyperhidrosis. Many medications affect the part of the brain that regulates body temperature, leading to an increase in sweat production. This provides more fuel for skin bacteria, which in turn leads to a more noticeable odor.

Altered Metabolism and Chemical Excretion

Some drugs can change your body's metabolic processes or contain compounds that are excreted through sweat or breath. A prime example is metformin, a diabetes medication that contains nitrogenous bases. These compounds can have a fishy odor, which some people notice upon opening the pill bottle, while others may experience it as a breath or body odor. A rare genetic condition called trimethylaminuria can also be exacerbated by certain medications and supplements, leading to a strong fishy smell.

Dry Mouth and Bad Breath

Certain medications can reduce saliva production, leading to dry mouth. Saliva helps control the number of bacteria in the mouth. When saliva decreases, bacteria can grow unchecked, leading to bad breath, also known as halitosis.

Changes in Skin Microflora

Antibiotics and antifungal drugs work by altering the balance of microorganisms in and on the body. This can lead to a shift in the types and quantities of bacteria on the skin, which can, in turn, change the characteristic scent produced when they interact with sweat.

Specific Drug Categories and Examples

Several classes of medications are commonly associated with changes in body odor. It's important to note that not everyone who takes these drugs will experience this side effect, as individual body chemistry plays a significant role.

Antidepressants

Selective Serotonin Reuptake Inhibitors (SSRIs): Common SSRIs like fluoxetine (Prozac) and sertraline (Zoloft) can cause excessive sweating in some individuals.
Tricyclic Antidepressants: Drugs such as desipramine (Norpramin) and amitriptyline (Elavil) are also known to cause hyperhidrosis.

Diabetes Medications

Metformin: As mentioned, this common type 2 diabetes drug can cause a fishy odor due to its chemical structure.
Oral Diabetes Medications and Insulin: Can cause increased sweating, altering body odor. A fruity or acetone-like smell on the breath can be a sign of a more serious diabetes complication, requiring immediate medical attention.

Supplements

B Vitamins: Certain B-complex supplements, particularly those containing choline, can cause a fishy odor in individuals with trimethylaminuria.
Zinc: High doses of zinc have been linked to increased sweating.

Other Notable Medications

Nonsteroidal Anti-inflammatory Drugs (NSAIDs): Some people report increased sweating with NSAIDs like naproxen.
Opioids: Pain medications like codeine and oxycodone can cause hyperhidrosis.
Chemotherapy Drugs: Cancer treatments can cause a wide range of metabolic changes, which can sometimes result in unusual body odors.
Thyroid Medications: For example, levothyroxine, can affect temperature regulation and lead to more sweating.

Managing Medication-Induced Body Odor

While a medication might be causing an unwanted odor, it's crucial not to stop your treatment without consulting a healthcare provider. Here are some strategies that can help manage the side effect:

Maintain Excellent Hygiene: Shower daily with antibacterial soap, paying special attention to areas with apocrine sweat glands like the armpits and groin.
Use Stronger Antiperspirants: Over-the-counter or prescription-strength antiperspirants can help control excessive sweating.
Choose Breathable Fabrics: Opt for natural, moisture-wicking materials like cotton, linen, and wool. Avoid synthetic fabrics like polyester and rayon, which can trap sweat and bacteria against the skin.
Stay Hydrated: Drinking plenty of water can help flush your system and dilute the concentration of excreted compounds.
Dietary Adjustments: Some foods high in sulfur, like garlic and onions, can also contribute to body odor. Reducing their intake might help.
Talk to Your Doctor or Pharmacist: Your healthcare provider can assess whether your medication is the cause and suggest alternatives or dose adjustments.

Comparison of Medications and Their Odor Effects

This table provides a quick overview of some common medication classes and how they can affect body odor:


Drug Class	Examples	Mechanism of Odor Change
Antidepressants (SSRIs, TCAs)	Fluoxetine, Sertraline, Desipramine	Increase sweat production (hyperhidrosis)
Diabetes Medications (Biguanides)	Metformin	Release nitrogenous bases, causing a fishy or metallic smell
Supplements	B vitamins (with choline), Zinc	Can be metabolized into odorous compounds or increase sweating
Antibiotics	Metronidazole, some Tetracyclines	Alter skin microflora, causing changes in smell; can also cause metallic taste and bad breath
Cancer Drugs	Leuprolide, some chemotherapy agents	Induce hormonal changes and affect metabolism, leading to unusual smells
Opioids	Codeine, Oxycodone	Increase sweat production
Thyroid Medications	Levothyroxine	Affect temperature regulation, potentially leading to more sweating

Conclusion

Experiencing a change in body odor after starting a new medication can be unsettling, but it's a common side effect for many drug classes. The causes can range from increased sweating to altered metabolism. The first and most important step is to discuss the issue with your doctor or pharmacist, who can confirm if your medication is the culprit and help explore management options, such as dose adjustments or alternative treatments. Maintaining good hygiene and making simple lifestyle changes can also significantly reduce discomfort. Remember, do not stop taking your prescribed medication without professional medical advice. For more detailed information on specific medications, consult the DailyMed database managed by the National Library of Medicine.

Frequently Asked Questions

Medication classes most likely to cause a weird smell include antidepressants, certain diabetes drugs like metformin, chemotherapy agents, and opioids. The odor is often caused by excessive sweating or metabolic changes induced by the drug.

Yes, medications that cause excessive sweating (hyperhidrosis), such as certain antidepressants and thyroid medications, can lead to increased body odor. The sweat itself is odorless, but when it interacts with skin bacteria, it creates a smell.

A metallic taste or bad breath can be a side effect of medications that cause dry mouth or alter your oral microflora. This effect is commonly seen with some antibiotics, antidepressants, and blood pressure medications.

Yes, it is normal for metformin tablets to have a fishy odor. This is due to the nitrogenous bases in the medication's chemical structure and does not indicate that the drug is spoiled or ineffective.

Yes, some supplements can cause unusual odors. High doses of certain B-complex vitamins, particularly those with choline, can cause a fishy body odor, especially in individuals with a genetic condition called trimethylaminuria. Zinc supplements have also been linked to increased sweating.

First, consult your doctor or pharmacist. Do not stop taking your medication. In the meantime, try strategies like showering daily with antibacterial soap, using a clinical-strength antiperspirant, and wearing breathable fabrics.

In many cases, the body odor subsides once you stop taking the medication that is causing it. However, this should only be done under the supervision of a healthcare provider, who may suggest an alternative treatment.

Yes, dietary changes can sometimes help. Reducing the intake of sulfur-rich foods like garlic, onions, and cabbage, and avoiding excessive caffeine and spicy foods, can potentially lessen the odor.