Famotidine: What It Is, Uses, Evidence & Safety

At a glance

Purpose, evidence and practical considerations.

What it’s for

Acid reflux and selected ulcer conditions

What the evidence says

Evidence supports labelled acid-related uses. Personal experiments for other goals do not establish anti-ageing or general metabolic benefits.

Confidence: strong

Clinical safety

Dose adjustment may be required in renal impairment. Headache, dizziness, constipation, or diarrhea can occur; medicine interactions and prolonged unsupervised acid suppression deserve review.

Medicines whose absorption depends on gastric acidity

How it works & important distinctions

Famotidine blocks histamine H2 receptors on gastric parietal cells and reduces stomach-acid secretion. That established mechanism does not validate off-label longevity or glucose claims.

Regulatory status: medication; availability and prescription status vary by dose and jurisdiction

Different forms

The evidence on this page does not automatically apply to:

combination antacid products containing famotidine
other H2 blockers
proton-pump inhibitors

In these protocols

How people use it, with their schedules, context and original sources.

Tim FerrissMedications

Date of record:: 10 Sep 2025

possible anti-COVID application and possible vagal-tone effects, as described by Ferriss

Details & sources

Over-the-counter H2 blocker, not a prescription. This records Ferriss's experimental rationale, not evidence of effectiveness or a recommendation.

Popular brands

Brand variants reported in public protocols. Private entries are excluded, and inclusion is not an endorsement.

Pepcid1 public entry

Other items in these protocols

These share a protocol with this intervention. This does not establish that they work together or are suitable alternatives.