When Is the Best Time to Take Low-Dose Aspirin — Morning or Night?

You may have heard that taking a low dose of aspirin every day can boost your heart health. Last year, the American Heart Association reported that more than 48% of U.S. adults age 20 and up have some form of cardiovascular disease, so it makes sense that you should take a daily aspirin, right? Not so fast. If you don't have heart problems, taking a low dose of aspirin might not be right for you.

“Typically, low-dose aspirin is for patients who have established atherosclerotic disease,” says Nishant Shah, M.D., an associate professor of medicine in cardiology at Duke University School of Medicine in Durham, NC. “Atherosclerotic disease means there’s evidence of cholesterol plaque in your arteries. Many patients with atherosclerotic disease have had prior heart attacks or strokes. Other patients can have atherosclerotic disease without having had a heart attack or stroke, but are still at risk of having either. Low dose aspirin can help in the prevention of cardiovascular events like heart attack or stroke in patients with atherosclerotic disease.”

According to Mayo Clinic, aspirin acts as a blood thinner. Any clots that build up inside a heart artery could block blood flow, leading to a heart attack or stroke, and aspirin can help stop a clot from forming.

If you’ve had a procedure, like a heart valve replacement, you may also be prescribed a low-dose regimen for a period of time. Beyond the cardiovascular system, though, a new study from the University of Hong Kong found that using low-dose aspirin for 10 years could cut a person's risk of lung, breast and colorectal cancer.

If you're curious, take a deeper dive into the specifics of taking low-dose aspirin below, including the best time to take it if your doctor does recommend it for you. Just don't start an aspirin regimen on your own. “You should consult with your doctor about whether or not low-dose aspirin is right for you,” stresses Kathryn J. Lindley, M.D., F.A.C.C., an associate professor of medicine and obstetrics and gynecology and director of the Women’s Heart Center at Vanderbilt University Medical Center in Nashville, TN.

Technically, any dose of aspirin that is 100 mg or less is considered to be a low dose. However, in the U.S., 81 mg is the most commonly prescribed low dose. The United States Preventative Task Force has made the following recommendations regarding aspirin use to prevent cardiovascular disease:

• Adults 40-59: A daily low-dose aspirin regimen may be recommended if a patient has 10% odds or higher of developing heart disease in the next decade.
• Adults aged 60 or older: A daily low-dose aspirin regimen isn’t recommended to prevent heart disease.
• All decisions regarding an aspirin regimen should be tailored to the individual patient.

It’s all about your medical history. “People who have previously experienced a heart attack, a stroke, or an intervention for coronary artery disease, such as a stent or bypass surgery, may have an indication for aspirin therapy for secondary prevention,” says Matthew I. Tomey, MD, FACC, FAHA, FSCAI, an interventional and critical care cardiologist at the Mount Sinai Fuster Heart Hospital in New York City.

“Your doctor will determine whether you would likely benefit from aspirin based on your risk factors such as age, blood pressure, cholesterol and diabetes history, as well as other factors like your family history,” says Dr, Lindley. “Sometimes additional testing such as a coronary calcium score may be performed to help understand your risk for a heart attack.” A new study points out that genetic testing may also play a helpful role in determining whether certain patients can benefit the most from an aspirin regimen.

Because aspirin is a blood thinner, anyone at higher risk for bleeding should not take it. According to Johns Hopkins Medicine, you should refrain if:

• You already take blood thinners, or you take corticosteroids. (Check with your doctor regarding ALL medications you take to avoid any interactions!)
• You have or have had ulcers, GI bleeding or gastritis.
• You have kidney failure.
• You have serious liver disease.
• You have any bleeding disorder.
• You have any clotting disorder.

“If you have a history or increased risk of bleeding or frequent falls, it's crucial to discuss this with your physician to weigh the benefits against the bleeding risks,” says Bhavna Suri, M.D., a cardiologist at Manhattan Cardiology in New York City.

A recent Italian study found that NSAIDs like aspirin can irritate the GI tract, and that serious GI complications like bleeding, perforation and obstruction happens in 1 to 2% of users. Additional research has shown that low-dose aspirin may also increase the risk of bleeding in the brain.

As a rule, not for most people. “It’s important to know that routine use of aspirin for primary prevention of heart disease is no longer recommended,” says Dr. Tomey. “By primary prevention, we mean preventing events like heart attack and stroke in individuals with no history of atherosclerotic cardiovascular disease. Selectively, physicians may recommend use of low-dose aspirin for prevention in some people at higher than average risk, such as those who are found to have evidence of plaque in their arteries on a diagnostic test, but who have not yet experienced a clinical event.”

Age is also a key factor. “Currently, aspirin for primary prevention — meaning that you don’t have known cardiovascular disease — is not recommended for patients over age 70, due to the increased risk of bleeding in older patients,” says Dr. Lindley. “Also, it’s not recommended for patients aged 40 to 69 who are considered low risk of heart attack, stroke and colorectal cancer, and patients under age 40 without known cardiovascular disease.”

You don’t have to, but it could make it easier for your body to digest the medication. “Taking aspirin with food or drink helps protect your stomach lining by reducing irritation, acid reflux, ulceration and a higher risk of bleeding,” says Dr. Suri. “A full glass of water also helps the tablet dissolve and be absorbed properly.”

“Through the years, there’s been no clear evidence to date that a particular time of administration is superior for prevention of heart attack and stroke,” says Dr. Tomey.

However, if your doctor gives you the green light for a daily low-dose aspirin, it’s important to stick to a schedule. “Try to be consistent and take it at the same time every day,” says Dr. Suri. Pair your aspirin with an “automatic” daily activity, like brushing your teeth or sitting down to breakfast with the family, and the less likely you’ll be to forget to take it.

If a low-dose aspirin regimen is right for you, follow your doctor’s instructions to the letter and don't be afraid to ask questions. “I encourage any patient who has been prescribed aspirin by a doctor to take a moment to learn about the reason for their aspirin prescription, and always to ask their doctor before starting or stopping aspirin therapy,” Dr. Tomey sums up. “It can also be quite helpful to consult with a preventive cardiologist to take a broader, personalized look at options beyond aspirin.” The more you learn about other potential treatment strategies, the better you’ll feel in every way.