Why should you not take aspirin on an empty stomach?

Taking aspirin on an empty stomach can lead to a number of issues and is generally not recommended. Here are some key reasons why you should avoid taking aspirin without food.

Increased risk of stomach irritation and ulcers

One of the main concerns with taking aspirin on an empty stomach is that it can irritate the delicate lining of the stomach. Aspirin is an NSAID (non-steroidal anti-inflammatory drug) and these types of medications can cause damage to the gastrointestinal (GI) tract, including ulcers and bleeding. When you take aspirin without any food, there is nothing to help cushion or coat the stomach lining. This leaves it more vulnerable to the direct irritating effects of the aspirin.

Several studies have found that taking aspirin on an empty stomach significantly increases the risk of developing gastric ulcers. One study published in the journal Lancet found that taking aspirin on an empty stomach was associated with a 3.5 fold increase in the risk of gastric ulcers, compared to taking it with or after food.

Another study published in the American Journal of Medicine looked at people taking low-dose aspirin for cardiovascular protection. They found that taking the aspirin on an empty stomach resulted in a 5-fold increase in the risk of upper GI bleeding, compared to taking it with food.

Therefore, taking aspirin without any food to line the stomach can substantially raise the risk of damage to the gastric mucosa. While aspirin irritates the stomach lining in general, food helps act as a buffer and minimize direct contact between the aspirin tablet and stomach walls.

Increased absorption and higher blood levels

In addition to increased gastric side effects, taking aspirin on an empty stomach can lead to faster absorption and higher blood concentrations of the drug.

A study published in the journal Thrombosis Research tested the effects of taking 100mg of aspirin on an empty stomach compared to after a meal. They found that taking aspirin on an empty stomach resulted in 34% higher plasma concentrations compared to when it was taken after food.

Other studies have confirmed that aspirin is absorbed faster and reaches higher systemic levels when administered without food. This is because food can delay gastric emptying time and slow down the absorption process from the stomach.

While reaching higher blood levels more quickly can sometimes be seen as a beneficial effect for medications, in the case of aspirin it also amplifies the risk of side effects. Higher circulating concentrations of aspirin mean greater exposure for the gastric mucosa and increased tendency to cause damage.

Increased risk of bleeding

Due to its blood thinning effects, taking aspirin on an empty stomach can also increase the risk of bleeding. Aspirin works by inhibiting platelet aggregation and clotting factors in the blood. This provides its protective benefits for the heart and circulation, but also raises the potential for abnormal bleeding.

Since taking aspirin without food allows for faster absorption and higher blood levels, this amplifies its anticoagulant effects. Studies have found a significantly increased risk of upper GI bleeding when aspirin is taken on an empty stomach, compared to with food. This bleeding can occur anywhere along the GI tract, including the stomach, duodenum or intestines.

In addition to GI bleeding, there may be a heightened risk of cerebral bleeding when aspirin reaches very high systemic concentrations. Therefore, taking it without food provides greater anticoagulant activity and increased potential for abnormal bleeding issues.

Decreased buffering effects

Food, especially carbohydrates and fiber, can help buffer stomach contents and reduce acidity levels. When you take aspirin without any food, you lose this buffering protection for your stomach lining.

Studies have found that even a modest amount of food can help protect the gastric mucosa from the effects of aspirin. This includes a reduction in bleeding times and less direct tissue irritation. Food helps coat the stomach and reduces exposure to concentrated aspirin sitting directly on the mucosal tissue.

Therefore, taking aspirin on an completely empty stomach deprives you of the buffering protection normally provided by food. Even eating a small snack with aspirin is better than nothing at all.

Tips for taking aspirin safely

If you regularly take aspirin for cardiovascular health, headaches or other reasons, keep these tips in mind to minimize the risks:

  • Always take aspirin with food – even just a glass of milk or piece of toast is better than nothing.
  • If you take it first thing in the morning, have some food first or take it with a full glass of water.
  • Consider an enteric-coated aspirin product which breaks down more slowly in the stomach.
  • Talk to your doctor if you have a history of GI ulcers or bleeding disorders.
  • Limit alcohol consumption, which also increases stomach irritation.
  • If gastric side effects develop, speak with your doctor about alternatives with lower bleeding risk.

Who should be particularly careful taking aspirin on an empty stomach?

While taking aspirin on an empty stomach is not advised for anyone, certain groups should be especially cautious about this practice:

  • Older adults – increased chance of GI bleeding and ulcers.
  • Those with a history of ulcers – high recurrence risk of ulceration.
  • People with hemorrhagic disorders – underlying bleeding risks are amplified.
  • Those taking anticoagulants – combined effects can heighten bleeding potential.
  • People with liver disease – decreased clearance of aspirin from blood.
  • Those who drink alcohol – exacerbated stomach irritation.

For these higher risk groups, it is strongly recommended to always take aspiring with food. If you have active ulcer disease, your doctor may advise avoiding aspirin completely, or limiting use to very specific circumstances where the cardiovascular benefits outweigh the bleeding risks.


Taking aspirin on an empty stomach is associated with increased risks, including higher likelihood of gastric irritation, ulcers, and bleeding. Aspirin absorbs more rapidly when no food is present, reaching higher systemic levels and amplifying adverse effects. Even eating a small amount of food can help buffer the stomach and minimize direct contact with concentrated aspirin. For best practice, always try to take your aspirin dose with at least a little food. If you are at high risk for bleeding issues, check with your doctor before routinely taking aspirin on an empty stomach.

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