NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Famotidine

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

A histamine-2 receptor antagonist used for the treatment and prevention of duodenal and gastric ulcers, GERD, erosive esophagitis, and conditions involving pathological gastric acid hypersecretion. Famotidine provides effective acid suppression with a favorable drug interaction profile compared to cimetidine.

Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

A histamine-2 receptor antagonist used for the treatment and prevention of duodenal and gastric ulcers, GERD, erosive esophagitis, and conditions involving pathological gastric acid hypersecretion. NutriStack rates the supporting evidence as strong. Common adult dosing is 20–40 mg once or twice daily (as prescribed by your physician), though a prescriber sets the actual dose. With long-term use it can deplete vitamin b12. This profile indexes 10 sources.

What it's good for
  • Relief of heartburn and acid indigestion
  • Healing of duodenal ulcers1,7
  • Treatment of GERD symptoms
  • Maintenance therapy for duodenal ulcer healing1,7
  • Treatment of pathological hypersecretory conditions
What to watch for
  • Headache
  • Dizziness
  • Constipation
  • Known hypersensitivity to famotidine or other H2 antagonists1,2
  • Severe renal impairment (dose adjustment required)

The bottom line

Evidence rating strong. Most-documented uses: relief of heartburn and acid indigestion, healing of duodenal ulcers, treatment of gerd symptoms. 10 sources indexed (1995–2025), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Competitively blocks histamine H2 receptors on the basolateral membrane of gastric parietal cells, inhibiting histamine-stimulated acid secretion. This reduces both basal and nocturnal acid output as well as acid secretion stimulated by food, pentagastrin, and other secretagogues.4

Class
H2 Receptor Antagonist
Dosing

Dosing & protocol.

Common range
20–40 mg once or twice daily (as prescribed by your physician)
Recommended form
Tablet or oral suspension; IV available

Can be taken with or without food; for heartburn prevention, take 15–60 minutes before eating trigger foods

Depletions

What it depletes.

Nutrients this medication can lower over time, and what to replace.

Vitamin B12

Mild

Chronic H2 receptor blockade reduces gastric acid needed to release food-bound vitamin B12 before intrinsic factor binding.

Replace MethylcobalaminMonitor Serum B12 + methylmalonic acidOnset Usually after months to years of continuous therapy
Safety

Full safety detail.

Side effects

  • Headache
  • Dizziness
  • Constipation
  • Diarrhea
  • Fatigue
  • Muscle cramps

Contraindications

  • Known hypersensitivity to famotidine or other H2 antagonists1,2
  • Severe renal impairment (dose adjustment required)
  • Caution in elderly patients (increased risk of confusion)
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

1

Randomized controlled trials

2

Reviews & position papers

2
FAQ

Common questions.

Quick answers about Famotidine, drawn from the data on this page.

What is Famotidine?

A histamine-2 receptor antagonist used for the treatment and prevention of duodenal and gastric ulcers, GERD, erosive esophagitis, and conditions involving pathological gastric acid hypersecretion. Famotidine provides effective acid suppression with a favorable drug interaction profile compared to cimetidine.

What is Famotidine used for?

Commonly cited benefits of Famotidine include: Relief of heartburn and acid indigestion; Healing of duodenal ulcers; Treatment of GERD symptoms; Maintenance therapy for duodenal ulcer healing; Treatment of pathological hypersecretory conditions. NutriStack rates the overall evidence as strong.

What is a typical dose of Famotidine?

A typical adult dose of Famotidine is 20–40 mg once or twice daily (as prescribed by your physician). The commonly recommended form is Tablet or oral suspension; IV available. These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Famotidine?

Reported side effects include headache, dizziness, constipation, diarrhea, fatigue, muscle cramps. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Famotidine?

NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Famotidine in NutriStack.

Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.