Anbesol liquid contains 20% benzocaine, a topical numbing agent that temporarily relieves pain from canker sores, toothaches, gum irritation, and denture sores. You apply a small amount directly to the painful spot inside your mouth, up to four times a day. The relief kicks in within about a minute and typically lasts 15 to 30 minutes, enough to get you through eating or to take the edge off persistent mouth pain.
How to Apply the Liquid
Start by washing your hands. If you’re opening a new tube, cut the tip at the score mark with scissors. Dry the sore or painful area as much as you can with a clean tissue or cotton pad. Moisture dilutes the liquid and makes it harder for the benzocaine to absorb into the tissue.
Apply a pea-sized amount of liquid directly onto the affected area. You can use a clean fingertip, a cotton swab, or a small piece of cotton. A cotton swab works especially well for reaching canker sores or spots along your gum line because it gives you more precision and keeps you from spreading the liquid to healthy tissue. Press the applicator gently against the sore for a few seconds to let the liquid absorb rather than just dabbing it on.
Try not to eat or drink for at least 10 to 15 minutes after application. The liquid needs time to numb the tissue, and food or beverages will wash it away. If you’re using it specifically to make eating less painful, apply it right before your meal and give it a minute to take effect.
Dosage Limits
Use no more than four applications per day unless a dentist tells you otherwise. Space them out as evenly as you can, roughly four to six hours apart, though you can apply it sooner if pain returns and you haven’t hit the daily maximum.
Do not use Anbesol liquid for more than seven consecutive days. If your mouth pain hasn’t improved after a week, something more than a simple sore is likely going on, and you need a professional evaluation. Persistent mouth sores can signal infection, an ill-fitting dental appliance, or other conditions that numbing alone won’t fix.
Using It for Denture Irritation
If you’re treating pain caused by dentures, remove the dental work first. Apply a thin layer of liquid to the irritated gum area. Leave the dentures out until the pain has eased. Before putting them back in, rinse your mouth thoroughly with water. Reinserting dentures over freshly applied benzocaine can trap the product against your gums longer than intended and irritate the tissue further.
Who Should Not Use It
Anbesol liquid is for adults and children age 2 and older. The FDA issued a formal warning that benzocaine oral products should never be used on infants or children under 2. In young children, benzocaine can cause a rare but dangerous blood condition called methemoglobinemia, where the blood’s ability to carry oxygen drops sharply. Symptoms include pale or blue-gray skin, rapid heartbeat, confusion, and shortness of breath. While this reaction is uncommon, it can be life-threatening.
Children between ages 2 and 12 should only use the product with adult supervision. An adult should control how much liquid is applied and make sure the child doesn’t swallow it.
The risk of methemoglobinemia isn’t limited to children. Adults with certain inherited enzyme deficiencies and older adults also face higher risk. If you’ve ever been told you have a sensitivity to local anesthetics or have experienced an unusual reaction to dental numbing, skip benzocaine products and ask your dentist about alternatives.
Signs of a Reaction
Most people tolerate Anbesol liquid without problems, but you should know what to watch for. A mild burning or stinging at the application site is normal and fades within seconds as the area goes numb.
Stop using the product and get medical attention if you notice any of the following:
- Pale, gray, or bluish skin, especially around the lips, nail beds, or fingertips, which can indicate methemoglobinemia
- Headache, dizziness, or rapid heart rate that starts shortly after application
- Swelling of the lips, tongue, or throat, which suggests an allergic reaction to benzocaine or one of the inactive ingredients
- Worsening redness or irritation at the application site after several days of use
Tips for Better Results
Benzocaine works by blocking nerve signals at the surface of your tissue, so full contact with the sore matters more than the amount you use. Piling on extra liquid won’t make it numb faster or last longer. It just increases the amount you might accidentally swallow.
If you’re using the liquid for a canker sore, applying it after brushing your teeth (gently, to avoid aggravating the sore) helps because your mouth is cleaner and the tissue is drier. Avoid mouthwash containing alcohol right before or after application, since it can sting and wash the benzocaine away.
Store the liquid at room temperature, away from direct heat and light. The tube’s tip can clog after repeated use. If that happens, clear it with a clean pin rather than squeezing harder, which can cause too much product to come out at once.