Losartan Side Effects: What You Need to Know Before Taking It

When you take Losartan, a blood pressure medication that blocks angiotensin II receptors to relax blood vessels. Also known as an angiotensin receptor blocker (ARB), it helps lower blood pressure and protects kidneys in people with diabetes. But like all meds, it doesn’t work the same for everyone—and side effects can show up even if you’ve taken it for months.

Most people tolerate Losartan just fine, but some notice dizziness, especially when standing up fast. That’s not just annoying—it can lead to falls. Fatigue is another common one, and it’s easy to blame on stress or lack of sleep when it’s actually the drug. Up to 1 in 10 users report a dry cough, which isn’t as frequent as with ACE inhibitors but still happens. More serious? High potassium levels. If you’re also taking potassium supplements, salt substitutes, or certain diuretics, your levels could spike without warning. That’s why your doctor checks your blood now and then.

Less common but dangerous? Swelling in your face, lips, or throat. That’s angioedema, and it needs emergency care. If you’ve had this reaction to any other ARB or ACE inhibitor before, you shouldn’t take Losartan at all. Also, if you’re pregnant—especially in the second or third trimester—Losartan can harm your unborn baby. It’s not just a risk; it’s a known cause of fetal injury. And if you’re on diuretics or have kidney disease, your dose might need adjusting. It’s not about fear—it’s about awareness.

What you won’t find in the pamphlet? How Losartan interacts with NSAIDs like ibuprofen. Taking them together can reduce Losartan’s effect and hurt your kidneys. Same with lithium—levels can build up to toxic amounts. Even herbal supplements like St. John’s wort or garlic pills can interfere. You’d think your pharmacist knows all this, but unless you tell them everything you’re taking, they can’t help. That’s why keeping a simple list of all your meds—prescription, over-the-counter, and supplements—is the smartest thing you can do.

Some side effects fade after a few weeks as your body adjusts. Others don’t. If you’re tired all the time, your blood pressure isn’t dropping, or you feel like something’s off—don’t ignore it. Talk to your doctor. Maybe it’s Losartan. Maybe it’s something else. But guessing won’t fix it. The good news? There are alternatives. Other ARBs like valsartan or irbesartan might work better for you. Or maybe a calcium channel blocker or thiazide diuretic is a better fit. It’s not about quitting Losartan—it’s about finding what works for your body.

In the posts below, you’ll find real comparisons and stories from people who’ve dealt with Losartan side effects, how they managed them, and what other options they tried. You’ll also see how Losartan stacks up against similar drugs, what to watch for when switching, and how to talk to your doctor without sounding alarmist. This isn’t just a list of warnings—it’s a practical guide to staying safe while getting the care you need.