Canker Sores, Explained by the Science
Not home remedies. Not medical disclaimers. Mechanisms, evidence levels, and honest answers — written by someone who's read every study so you don't have to.
Every claim is sourced. Every treatment is evidence-rated.
Core Guides
The five pages every canker sore sufferer should read.
What Are Canker Sores? The Complete Guide to Aphthous Ulcers
Canker sores (aphthous ulcers) are painful oral lesions affecting 20% of the population. Here's the actual science on what they are, their three types, and what makes them distinct from cold sores.
Read guide →What Causes Canker Sores? — Mechanisms, Not Just Triggers
Canker sores are immune-mediated, not viral. Here's the actual mechanism — why immune dysregulation, nutritional deficits, SLS, stress, and genetics all converge to destroy the oral epithelium.
Read guide →Best Supplements for Canker Sore Prevention — Evidence-Graded Review
L-lysine, B12, zinc, iron, folate — which supplements actually reduce canker sore frequency? We grade the evidence for each and recommend specific products.
Read guide →Natural Remedies and Home Remedies for Canker Sores — Do They Actually Work?
Salt water, Manuka honey, baking soda, ACV, aloe — every popular natural canker sore remedy graded by what the evidence actually shows. Some work. Most don't. A few are actively harmful.
Read guide →How to Get Rid of a Canker Sore Fast — Evidence-Ranked Treatments
OTC and prescription treatments ranked by what actually speeds healing versus what just numbs pain. Steroid gels, cauterization, laser — and what to do right now if you have one.
Read guide →Canker Sore vs. Cold Sore — How to Tell Them Apart (And Why It Matters)
Canker sores and cold sores are completely different conditions — one is immune-mediated and non-contagious, the other is a contagious herpes virus. Getting this wrong means treating with the wrong drugs. Here's how to tell them apart definitively.
Read guide →Get the Treatments Guide
Free 2-page PDF: every canker sore treatment grouped by how it works and rated by the actual evidence — what speeds healing, what only numbs pain, and what's a waste of time.
Recent Research Notes
All articles →Acid Reflux and Canker Sores — What's the Connection?
Acid reflux doesn't directly cause canker sores — they're immune-mediated, not acid-caused. But the medications used to treat GERD deplete B12 over time, and that's a real canker sore driver. Here's what's actually connecting the two.
Read →Apple Cider Vinegar for Canker Sores — Why You Shouldn't Use It
Apple cider vinegar is one of the most commonly recommended home remedies for canker sores and one of the worst. It's highly acidic, the rationale doesn't match the mechanism, and applying it to an open wound causes damage. Here's the full debunk.
Read →Vitamin B12 for Canker Sores — The Evidence, the Right Form, and Who It Helps Most
B12 is the best-evidenced supplement for canker sore prevention — an RCT found 1000mcg sublingual nightly reduced outbreak frequency significantly, even in people whose serum B12 was already normal. Here's the mechanism, who needs it most, and why the delivery method matters.
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