Valsartan is not a blood thinner. It belongs to a completely different class of medications called angiotensin II receptor blockers (ARBs), which lower blood pressure by relaxing blood vessels. Blood thinners work by reducing your blood’s ability to clot, and valsartan does not do that.
How Valsartan Actually Works
Your body naturally produces a substance called angiotensin II that tightens blood vessels. Valsartan blocks angiotensin II from binding to its receptors, which allows blood vessels to relax and widen. The result: blood flows more smoothly, blood pressure drops, and your heart doesn’t have to work as hard to pump.
This is fundamentally different from what blood thinners do. The American Heart Association categorizes blood thinners into two types: anticoagulants (like warfarin, dabigatran, and rivaroxaban), which decrease the blood’s clotting ability, and antiplatelet drugs (like aspirin and clopidogrel), which prevent platelets from sticking together. Neither mechanism has anything to do with blood vessel relaxation. You could think of it this way: blood thinners change the blood itself, while valsartan changes the pipes the blood flows through.
A Nuance Worth Knowing
Interestingly, valsartan may have a mild secondary effect on platelets. A clinical trial called the Valsartan Inhibits Platelets (VIP) study found that valsartan produced sustained inhibition of platelet aggregation, meaning it reduced how readily platelets clumped together. This effect was even more pronounced in patients with diabetes. However, this antiplatelet activity is not strong enough for valsartan to be classified or prescribed as a blood thinner. If you need clot prevention, your doctor will prescribe an actual anticoagulant or antiplatelet drug alongside valsartan, not instead of it.
What Valsartan Is Prescribed For
Valsartan has three FDA-approved uses:
- High blood pressure (hypertension): The most common reason people take it. Lowering blood pressure reduces the risk of strokes and heart attacks. Typical doses range from 80 to 320 mg once daily.
- Heart failure: Valsartan significantly reduces hospitalizations in people with heart failure. In patients not taking another type of blood pressure drug called an ACE inhibitor, valsartan cut the risk of death by 33% and reduced heart failure hospitalizations by 53% compared to placebo. The target dose for heart failure is 160 mg twice daily.
- After a heart attack: For people with heart damage following a heart attack, valsartan helps reduce the risk of dying from cardiovascular causes. It’s started at a low dose of 20 mg twice daily and gradually increased.
Common Side Effects
Because valsartan lowers blood pressure, the most important thing to watch for is your blood pressure dropping too low, especially if you’re dehydrated from vomiting, diarrhea, or not drinking enough fluids. Symptoms of low blood pressure include dizziness, lightheadedness, and feeling faint.
Valsartan can also raise potassium levels in your blood. Symptoms of high potassium include irregular heartbeat, numbness or tingling in your hands and feet, muscle weakness, and nausea. You should avoid potassium supplements or potassium-containing salt substitutes unless your doctor has specifically okayed them.
Less bothersome side effects include mild cough, diarrhea, and headache. These often improve as your body adjusts to the medication.
Why the Confusion Happens
People often wonder whether their heart medications are blood thinners because many cardiac patients take both types of drugs. If you’ve had a heart attack or have heart failure, you might be prescribed valsartan alongside an actual blood thinner like aspirin or warfarin. Seeing multiple medications on your list, all aimed at protecting your heart, makes it easy to assume they work the same way. They don’t. Valsartan keeps your blood vessels relaxed and your blood pressure controlled. Blood thinners prevent dangerous clots. They tackle different parts of the same problem, which is exactly why they’re sometimes prescribed together.