Oral health · evaluated online

Canker sores
(aphthous ulcers)

Canker sores are common, painful, and not contagious. Most heal in 7–14 days. Prescription topicals can speed healing and reduce pain.

Licensed clinicians · Available in all 50 states
Canker sores
Common Rx
Triamcinolone in Orabase, fluocinonide gel
Time to feel better
Pain relief: immediate; healing: 7–14 days
Contagious
No
Telehealth fit
Yes — photos help

What is canker sores?

Canker sores (aphthous ulcers) are small painful round or oval ulcers inside the mouth — on cheeks, gums, tongue, or lip. Affect about 20% of US adults. Not contagious and not related to herpes (cold sores).

Most resolve on their own in 1–2 weeks. Prescription topical treatments help with pain and speed healing. Frequent severe cases may benefit from systemic evaluation.

Do I have canker sores? Common signs

If most of these describe what you're experiencing, telehealth may be a good next step:

Small round/oval ulcer with white-yellow center, red border Painful — especially with eating, drinking, talking Tingling or burning before ulcer appears Inside cheeks, lips, tongue, gums Often single, sometimes multiple Heal without scarring Recurrent — same person gets them repeatedly
Here's how it actually works
01
Tell us what's going on5-minute online intake covers your symptoms, history, and any photos.
02
A clinician reviewsLicensed in your state. Reviews your case and asks anything needed.
03
Rx to your pharmacyIf treatment is appropriate, the prescription goes to the pharmacy you choose.

What causes it

Unknown but linked to stress, oral trauma (biting cheek, dental work), certain foods (acidic, spicy), vitamin deficiencies (B12, iron, folate), hormonal changes, SLS in toothpaste, gluten sensitivity, some medications. Family history common.

Is it contagious?

No.

If you get more than 3 per year, ask about B12, iron, and folate — deficiency drives many recurrent cases.

Can it be treated online?

Routine canker sores are well-suited to telehealth. Frequent or severe cases benefit from systemic workup (vitamin levels, celiac, IBD). Lesions lasting >3 weeks, very large, or atypical need in-person evaluation to rule out oral cancer.

How canker sores is treated

Topical steroids: triamcinolone in Orabase, fluocinonide gel — applied 3–4x daily speeds healing. OTC options: benzocaine, hydrogen peroxide rinse, sodium bicarbonate rinse. Chlorhexidine rinse for recurrent cases. Treat underlying vitamin deficiencies. Severe recurrent cases may need colchicine or prednisone.

Self-care while you wait

When to skip telehealth and seek emergency care Large ulcer (>1 cm), lasting more than 3 weeks, painless ulcer, persistent — needs in-person evaluation for oral cancer. Fever with multiple ulcers, especially with rash — could be Stevens-Johnson or other systemic illness.

How long does it last?

Individual sores: 7–14 days. Recurrent in many people, often monthly.

Frequently asked questions

Are canker sores the same as cold sores?

No. Canker sores are inside the mouth, not contagious, not herpes. Cold sores are on/near lips, caused by HSV-1.

Why do I keep getting them?

Common triggers: stress, dental work, SLS toothpaste, certain foods, vitamin deficiencies, hormonal cycles.

Is it serious?

Usually no. Persistent or unusual ulcers should be evaluated to rule out oral cancer, immune conditions, or systemic disease.

Will any vitamin help?

B12, iron, folate, zinc deficiencies are linked. Reasonable to check levels if recurrent.

Can I use Listerine?

Alcohol-based rinses can sting and aren't proven to help. Salt water or alcohol-free rinses are better.

This page is for general information only — not a substitute for individual medical advice. A licensed clinician reviews every intake submitted through PrescriberNow before any prescription is issued. If you're experiencing a medical emergency, call 911 or go to the nearest emergency room.

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