Phototoxicity: What It Is, Which Drugs Cause It, and How to Stay Safe

When you take a medication and your skin reacts badly to sunlight, it’s not just a sunburn—it could be phototoxicity, a severe skin reaction triggered by certain drugs when exposed to ultraviolet light. Also known as drug-induced photosensitivity, it happens when a medication absorbs UV rays and turns into a harmful substance that damages your skin cells. This isn’t rare. It’s one of the most common but overlooked side effects of everyday prescriptions and even some supplements. People think they’re just getting sunburned, but the reaction is deeper, faster, and often worse than a normal burn.

Phototoxicity isn’t caused by all drugs—only specific ones. tetracycline antibiotics, a class of drugs used for acne, respiratory infections, and other bacterial conditions, are classic culprits. So are nonsteroidal anti-inflammatory drugs, like ibuprofen and naproxen, commonly taken for pain or swelling. Even some diuretics, including indapamide, used to treat high blood pressure and heart failure, can make your skin hypersensitive. You don’t need to be out all day—just 15 minutes of midday sun can trigger a blistering reaction if you’re on the wrong med. The skin turns red, swells, burns, and sometimes peels like a bad sunburn, often in patterns that match where your clothes were loose or your skin was exposed.

What makes phototoxicity tricky is that it doesn’t show up right away. You might take your pill for weeks, enjoy the sun without issue, then suddenly your arms or neck break out in a painful rash after a walk in the park. It’s not an allergy—it’s a chemical reaction. Your body doesn’t reject the drug; the drug reacts with sunlight. That’s why you can’t just stop the medicine and expect it to go away overnight. You need to avoid UV exposure until the drug clears your system, which can take days or even weeks depending on the medication. And if you keep going out without protection, you risk long-term damage—premature aging, dark spots, or even an increased risk of skin cancer.

Some people think sunscreen is enough, but most sunscreens don’t block the full range of UV wavelengths that trigger phototoxicity. You need to stay out of direct sun, wear tightly woven clothing, and use broad-spectrum UV-A/UV-B protection—even on cloudy days. If you’re on a drug known to cause this reaction, check your medication guide. The FDA requires manufacturers to warn about photosensitivity risks if they exist. Don’t ignore it. A simple change in routine—like taking your pill at night instead of morning, or avoiding the beach during peak hours—can prevent a hospital visit.

Below, you’ll find real-world guides on drugs that cause phototoxicity, how to recognize the warning signs before it gets serious, and what to do if you’ve already been burned. Whether you’re on antibiotics, blood pressure meds, or even a daily supplement, this collection gives you the facts you need to stay safe without giving up your life.