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Overview: Aspirin is used to treat pain and fever. Common side effects can include an upset stomach or heartburn. Serious side effects are less common but may include allergic reactions or stomach bleeding. Tell your health care provider right away if you have stomach pain that will not go away, vomit blood, or notice blood in your poop. Aspirin is available in many forms, including tablets that are chewed, swallowed, or dissolved in water to drink.

Uses

What is aspirin used for?

Aspirin is commonly used for the following.

Aspirin may also be used for other conditions as determined by your health care provider.

How does aspirin work (mechanism of action)?

Aspirin works by blocking certain substances in the body that cause pain, inflammation, and fever.

How is aspirin supplied (dosage forms)?

Brands and other names

  • Bayer
  • Vazalore

Dosage forms and strengths

  • 81 mg chewable tablets
  • 81 mg, 325 mg oral capsules
  • 81 mg, 325 mg delayed-release oral tablets
  • 81 mg, 325 mg, 500 mg oral tablets
  • 300 mg rectal suppositories
  • 325 mg effervescent tablets

How should I store aspirin?

Tablets and Capsules. Aspirin tablets and capsules should be stored at room temperature. Some products may also have directions on them to avoid exposing them to excessive heat, such as temperatures over 104 F (40 C). Follow the instructions on the product you have. Ask your pharmacist if you have any questions about how to store your medicine.

Rectal Suppositories. Aspirin suppositories should be stored in the refrigerator or a cool area, between 46 F and 59 F (8 C and 15 C). 

Side Effects

What are the most common side effects of aspirin?

The most common side effects of aspirin are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Stomach problems, including pain or nausea
  • Rash

There may be other side effects of aspirin that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of aspirin?

While less common, the most serious side effects of aspirin are described below, along with what to do if they happen.

Severe Allergic Reactions. Aspirin may cause allergic reactions, which can be serious. Stop taking aspirin and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or bumps on the skin called hives that can be red, pink, white, or brown, depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Stomach Bleeding. Aspirin can increase your risk of bleeding, ulcers, and tears (perforation) in your gut. The risk is higher if you have a history of stomach ulcers, bleeding problems, take higher doses of aspirin or take it for longer than directed, have poor health, are age 60 or older, have liver disease, smoke, drink alcohol, or take certain other medicines. Stop taking aspirin and get emergency help if you have any of the following symptoms.

  • Vomit blood
  • Black or tarry poop
  • Stomach pain that does not go away
  • Upset stomach
  • Feel faint

Hearing Loss. Aspirin may be associated with hearing loss, which is also called ototoxicity. Tell your health care provider right away if you have hearing loss or if you hear a ringing or roaring sound in your ears.

Reye’s Syndrome. Children or teenagers who have chicken pox, the flu, or flu-like symptoms should not take aspirin to treat these things. Taking aspirin to treat an infection caused by a virus can lead to Reye’s Syndrome. If your child or teenager is taking aspirin and shows signs like changes in their behavior, nausea, and vomiting, contact your health care provider. Behavior changes, nausea, or vomiting could be early signs of Reye’s Syndrome. 

Warnings & Precautions

Who should not use aspirin?

Allergies to Ingredients. People who are allergic to any of the following should not use aspirin.

  • Aspirin
  • Bayer
  • Vazalore
  • Any other medicine known as a pain reliever or fever reducer
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific aspirin products they stock.

Mouth or Tonsil Surgery. You should not take aspirin for at least seven days after having surgery in your mouth or your tonsils taken out, unless your health care provider tells you to.

 

What should I know about aspirin before using it?

Taking aspirin with food or with a full glass of water may reduce your risk of having stomach-related side effects. Talk to your health care provider if you have concerns.

Keep aspirin out of the reach of children.

Stop taking aspirin and call your health care provider if any of the following apply to you.

  • Your pain is getting worse or lasts longer than 10 days.
  • Your fever is getting worse or lasts longer than three days.
  • The painful area is red or swollen.
  • You have new symptoms since you started taking aspirin.

If you are using aspirin suppositories, you need to take the suppository out of the wrapper before inserting it into your rectum. Ask your health care provider if you are not sure how to use a suppository. 

People who are 60 or older can be at greater risk of some side effects from aspirin. Talk to your health care provider about your risks if you are in this age group.

What should I tell my health care provider before using aspirin?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if aspirin is right for you.

In particular, make sure that you discuss any of the following.

Other Medicines and Supplements. Aspirin may interact with other medicines and supplements. Before taking aspirin, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • If you are 60 years or older
  • Asthma
  • Stomach problems, including stomach ulcers or heartburn
  • Bleeding problems
  • High blood pressure
  • Heart disease
  • Liver problems, including cirrhosis
  • Kidney problems
  • Drink alcohol regularly

Pregnancy. Do not take aspirin at 20 weeks or later in pregnancy without talking to your health care provider. Taking aspirin during this time may cause harm to a fetus and complications during delivery. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will let you know if you should use aspirin while you are pregnant or trying to get pregnant.

Breastfeeding. Aspirin passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should stop breastfeeding or stop taking aspirin.

Interactions

Does aspirin interact with foods or drinks?

There are no known interactions between aspirin and foods or drinks.

Drinking alcohol regularly may increase your risk of side effects with aspirin. It is best to limit the amount of alcohol you drink. 

Does aspirin interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking aspirin.

  • A blood thinner, which is a medicine used to treat or prevent blood clots
  • A nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen, naproxen, and others, which is in many prescription and OTC products for pain, swelling, and fever
  • A corticosteroid, such as dexamethasone, methylprednisolone, or prednisone, which is a medicine for certain inflammatory conditions
  • A diuretic, also called a water pill, which is a medicine used to reduce edema (fluid retention) and blood pressure
  • A medicine for gout
  • A medicine for diabetes
  • A medicine for arthritis

This may not be a complete list of medicines that can interact with aspirin. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much aspirin?

If you or someone else has used too much aspirin, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of aspirin?

Aspirin is meant to be used only when needed. Use it according to the product label. If you miss a scheduled dose, take it as soon as you remember it. If it is almost time for your next dose, skip the missed dose and only take the next one. Do not take double or extra doses. Do not take more than is recommended on the product label.