Anbesol is an over-the-counter numbing gel used to temporarily relieve pain inside the mouth, including toothaches, canker sores, sore gums, and general mouth irritation. Its active ingredient, benzocaine, is a local anesthetic that dulls pain on contact, typically within a minute or two of application.
How Anbesol Works
Benzocaine, the active ingredient in Anbesol, works by blocking sodium channels in nerve cells near the surface of your gums or inner cheeks. Normally, these channels allow electrical signals to travel along nerves to your brain, which is how you feel pain. Benzocaine slips into those channels and temporarily shuts them down, stopping the pain signal before it ever reaches your brain. The effect is localized, meaning it only numbs the small area where you apply it.
The maximum strength formula contains 20% benzocaine. Relief typically kicks in quickly but wears off within 30 to 60 minutes, which is why reapplication is sometimes needed.
Common Uses
Anbesol is designed for short-term pain relief inside the mouth. The most common reasons people reach for it include:
- Toothaches: When you can’t get to a dentist right away, Anbesol can take the edge off throbbing tooth pain.
- Canker sores: These shallow ulcers on the inner lips or cheeks can make eating miserable. A small dab of Anbesol numbs the area enough to get through a meal.
- Sore or irritated gums: Pain from new dentures, braces, or minor gum injuries responds well to topical benzocaine.
- Sore throat and general mouth pain: Some formulations are used for throat irritation, though lozenges and sprays are more common for that purpose.
It’s worth noting that Anbesol treats the symptom, not the cause. A toothache that keeps coming back likely signals a cavity, crack, or infection that needs professional treatment. Anbesol buys you time; it doesn’t fix the underlying problem.
How to Apply It
For adults and children 2 years and older, the standard recommendation is to apply a pea-sized amount directly to the painful area up to four times daily. You can use a clean finger or a cotton swab. Avoid eating or drinking for a few minutes afterward so the product stays in place long enough to work.
Anbesol comes in liquid and gel forms. The gel tends to stay put on a specific spot like a canker sore or a sore on the gum line, while the liquid spreads more easily across a broader area. Which one works better depends on where your pain is and how targeted you need the relief to be.
Side Effects
Most people tolerate Anbesol without issues, but minor side effects do occur. A brief burning or stinging sensation right after application is the most common complaint, and it usually fades within seconds. Some people develop contact dermatitis (redness, itching, or a rash) or hives at the application site, which suggests a sensitivity to benzocaine. If that happens, stop using it.
The serious risk with benzocaine is a rare blood condition called methemoglobinemia. In this condition, hemoglobin in your red blood cells changes form and loses its ability to carry oxygen effectively. Early symptoms include fatigue, lightheadedness, headache, and a bluish tint to the skin or lips. At higher severity levels, it can cause rapid heart rate, confusion, difficulty breathing, and in extreme cases, it can be fatal. This reaction is uncommon with normal topical use, but the risk is real enough that the FDA has issued specific warnings about it.
Not Safe for Teething Babies
This is the single most important safety point about Anbesol: it should not be used for teething pain in infants or young children under 2. The FDA has warned that benzocaine products, including Anbesol, Orajel, and similar brands, pose a serious methemoglobinemia risk in young children and provide little actual benefit for teething discomfort.
The American Academy of Pediatrics recommends safer alternatives for teething babies. Gently rubbing the baby’s gums with a clean finger can provide relief, as can giving them a firm rubber teething ring to chew on. The ring shouldn’t be frozen, since something too hard can actually hurt tender gums. Liquid-filled teethers are also best avoided, since they can break.
Who Should Be Cautious
Beyond the age restriction for young children, certain people face a higher risk of complications from benzocaine. Those with anemia, heart disease, or lung disease are more vulnerable to the effects of methemoglobinemia because their bodies are already working harder to deliver oxygen. If you’ve ever had a reaction to a local anesthetic at the dentist, or if you’ve experienced methemoglobinemia before, benzocaine products are not a good choice for you.
Smoking and certain medications can also increase the risk by affecting how your blood carries oxygen. If you’re using Anbesol frequently or in larger amounts than directed, the risk goes up as well. Sticking to the recommended pea-sized amount, no more than four times a day, keeps your exposure in a safe range for most adults.