Inhalers: How They Work, What to Watch For, and Common Safety Risks

When you use an inhaler, a medical device that delivers medication directly into the lungs. Also known as metered-dose inhalers or MDIs, they’re one of the most common ways to treat asthma, COPD, and other breathing conditions. But not all inhalers are created equal. Fake or poorly made ones can contain no medicine at all—or worse, toxic chemicals. The FDA has detained shipments of counterfeit inhalers entering the U.S., and many patients don’t even realize they’re using them until it’s too late.

Real inhalers need precise dosing. Each puff must release exactly the right amount of drug—too little and your symptoms won’t improve; too much and you risk side effects like rapid heartbeat or tremors. That’s why proper technique matters just as much as the device itself. Many people don’t coordinate their breath with the spray, which means up to 80% of the dose ends up in their mouth instead of their lungs. This isn’t just inefficient—it’s dangerous. If you’re using a steroid inhaler and not rinsing your mouth afterward, you could develop oral thrush. If you’re using a rescue inhaler too often, it might mean your condition is getting worse, not better.

Counterfeit inhalers are often sold online or through unlicensed pharmacies. They might look real, but the packaging can have typos, wrong colors, or missing lot numbers. Some fake inhalers have no active ingredient—just air. Others contain the wrong drug entirely. In developing nations, this is a major cause of preventable deaths. Even in the U.S., people buying from unverified sources risk getting contaminated or expired devices. The FDA drug inspections, a system that screens millions of drug shipments annually catch some, but not all. And if your inhaler came from a website that doesn’t ask for a prescription, it’s probably not safe.

There’s also the issue of drug interactions. Some inhalers contain beta-agonists that can interfere with heart medications. Others include corticosteroids that lower your immune response over time. If you’re on multiple drugs, especially for conditions like diabetes or high blood pressure, your inhaler could be making things worse without you knowing. That’s why reading the prescription drug labels, the safety warnings printed on medication packaging is critical. Look for black box warnings, contraindications, and interactions listed under "Drug Interactions."

What you’ll find below are real, practical guides from patients and doctors who’ve dealt with these issues firsthand. You’ll learn how to spot fake inhalers before you buy them, how to use them correctly so they actually work, what to do if you think your inhaler isn’t helping, and how to avoid dangerous interactions with other medications. These aren’t theory pieces—they’re based on FDA reports, patient stories, and clinical data from real cases. Whether you’re managing asthma, COPD, or just trying to make sure your inhaler isn’t putting you at risk, this collection gives you what you need to stay safe.