Sucralfate: what it does and what to watch

Also known as: Mucosal protectant, Ulcer-coating agent · Gastric mucosal protectant · Updated 2026-08-20 · Educational — not medical advice

Illustrative — a raw patch on the stomach wall

In plain language: Rather than reducing acid production, this medicine forms a sticky, protective coating over ulcers and irritated areas of the stomach and upper intestine lining. This physical barrier shields the damaged tissue from acid, digestive enzymes, and bile, giving it a chance to heal, and it works largely within the gut rather than being absorbed into the bloodstream in meaningful amounts.

What it's used for

  • Stomach and duodenal ulcers
  • Protecting the stomach lining during ulcer healing
  • Certain cases of stress-related stomach lining irritation

Common side effects

  • Constipation
  • Dry mouth
  • Nausea
  • Stomach discomfort or bloating
  • Mild dizziness

Get medical help if…

Bezoar formation (a hardened mass of undigested material) has rarely been reported, particularly in people who are critically ill or have delayed stomach emptying

Aluminum accumulation in the body with prolonged use, particularly of concern in people with significantly reduced kidney function, since this medicine contains an aluminum compound

Reduced absorption of certain other medicines if taken too close together, potentially reducing their effectiveness

Signs of a severe allergic reaction, though this is rare

Lab values it can move

Few guides tell you this part: medicines show up in blood work. If you take Sucralfate and a value below looks off on your report, this may be part of the story — never stop a medicine without your doctor.

This medicine contains an aluminum-based compound; with prolonged use, particularly in people with significant kidney impairment who cannot clear aluminum normally, calcium and related mineral balance is sometimes monitored as a precaution.

Calcium

Good to know

  • Take this medicine on an empty stomach, generally before meals, since food can reduce how well it coats the stomach lining
  • Space other medicines apart from this one by a couple of hours where possible, since it can reduce the absorption of some other drugs
  • People with significantly reduced kidney function should discuss long-term use with a prescriber, given the aluminum content
  • Increase fluid and fiber intake if constipation develops, and mention persistent constipation to a prescriber
  • This medicine treats symptoms and supports healing but doesn't address underlying causes of ulcers, such as certain infections or long-term use of pain relievers, which may need separate treatment

Questions people ask

Why do I need to take this on an empty stomach?

This medicine works by forming a protective coating over ulcers in the stomach lining, and it needs direct contact with the affected tissue to do this effectively. Food in the stomach can get in the way of that coating action, which is why it's generally taken before meals on an empty stomach, giving it the best chance to adhere to the ulcer site.

Can I take my other medicines at the same time as this one?

It's often better not to, since the coating this medicine forms can also bind to some other medicines in the gut and reduce how much of them gets absorbed into the body. Spacing other medicines a couple of hours apart from this one, where practical, helps avoid this interaction; a pharmacist can advise on specific timing for your other medicines.

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