Body Odor: Causes, Medications, and How to Manage It

When you notice a change in your body odor, an unpleasant smell produced by bacteria breaking down sweat on the skin. Also known as bromhidrosis, it’s not always about poor hygiene—it can be tied to what’s inside your body, including the medications you take. Many people assume strong body odor means they’re not showering enough, but that’s not always true. Sometimes, it’s your medicine.

Take anticholinergic overload, a condition caused by combining drugs that block acetylcholine, leading to reduced sweat and dry skin. Medications like amitriptyline (a tricyclic antidepressant) or diphenhydramine (found in Benadryl) can shut down your sweat glands. At first, that sounds good—less sweat, less odor, right? But when your body stops sweating, it doesn’t mean odor disappears. It just changes. Bacteria thrive in the damp, warm areas that aren’t being washed away by sweat, and the smell becomes stronger, funkier, and harder to control. Older adults are especially at risk, and many don’t connect their worsening body odor to their meds.

Then there are antihistamines, drugs used for allergies that also reduce sweat as a side effect. Used daily for eczema or hay fever, they can silently alter your body’s natural cooling system. Over time, trapped moisture and dead skin cells build up, feeding odor-causing bacteria in places like armpits, feet, and groin. It’s not the sweat itself that smells—it’s what grows in it. And if you’re already using topical treatments for skin conditions, those can mix with altered skin chemistry to make things worse.

Body odor isn’t just a personal annoyance. It can affect confidence, social life, even mental health. But the fix isn’t always more deodorant. Sometimes, it’s about looking at your pill bottle. If you’ve noticed a sudden shift in how you smell—and you started a new medication around the same time—it’s worth asking your doctor. Could your antihistamine or antidepressant be the hidden cause? Are there alternatives that don’t dry you out?

You’ll find posts here that dig into how common drugs like those for heart conditions, depression, and allergies quietly change your body’s chemistry. Some explain why switching from one statin to another doesn’t touch your odor, but changing your anticholinergic combo might. Others show how simple hygiene tweaks—like using antibacterial soap or changing fabrics—can help when meds can’t be changed. This isn’t about quick fixes. It’s about understanding the real reasons behind the smell, and what you can actually do about it.