Benzocaine: Side Effects, FDA Warnings & Lawsuit Information

Benzocaine is a local anesthetic found in gels, lozenges and sprays. It’s often used orally to treat conditions like toothaches, sore throats, canker sores and gum discomfort.

As a topical application, it can help alleviate pain associated with minor skin issues, including sunburns and insect bites. Doctors also use benzocaine during dental procedures and before anesthesia.

Benzocaine is similar to another local anesthetic called lidocaine. While lidocaine also aids with pain relief, benzocaine is less potent and shorter-acting. Lidocaine is stronger and can be used for local anesthesia in medical procedures or administered intravenously for intubated patients.

Benzocaine is available in several over-the-counter forms, including gels for oral pain relief and sprays for sore throats. However, the FDA reports that benzocaine sprays may increase your risk of blood oxygen issues when used for medical procedures.

Another option is benzocaine menthol. This combines the anesthetic with menthol, an organic compound that provides a cooling sensation, to create soothing lozenges for sore throats.

People who use benzocaine often report minor side effects like local irritation and tingling. Benzocaine users may also experience serious risks that could be life-threatening, including allergic reactions, heart issues and a rare blood disorder called methemoglobinemia.

As of November 1, 2025, the Food and Drug Administration’s (FDA) Adverse Events Reporting System (FAERS) had received over 1,400 adverse event reports related to Benzocaine. Roughly 75% of these cases were serious.

Disclaimer: Reports sent to the FDA don’t necessarily mean the drug caused an adverse event. Consult a health care professional before stopping or changing medication.

Common Benzocaine Side Effects

Localized skin or application-site reactions are frequently reported by benzocaine users. These side effects are typically mild.

If you experience any side effects while taking benzocaine, report them to your doctor.

Serious Benzocaine Side Effects

The most serious benzocaine side effects include allergic reactions, heart rate changes and a rare but life-threatening blood disorder called methemoglobinemia.

Severe allergic reactions to benzocaine can cause anaphylaxis, which is sometimes fatal. It may also lead to contact dermatitis, which can cause your skin to slough off and become infected.

Notify your doctor if you notice symptoms like difficulty breathing, changes in your heart rate, swelling or skin irritation. These could indicate a serious health condition requiring medical attention.

Benzocaine and Methemoglobinemia

Some benzocaine users develop a potentially fatal complication called methemoglobinemia. This condition causes elevated levels of methemoglobin in your blood.

Methemoglobin is a type of protein that cannot bind to oxygen. Excess levels reduce the amount of oxygen carried through your blood.

Seek medical attention if you notice symptoms consistent with methemoglobinemia. These symptoms worsen as methemoglobin levels increase in the blood. If left untreated, the condition can cause coma or death.

After undergoing stomach surgery, a 46-year-old woman used a benzocaine throat spray to relieve her pain. However, she used too much of the spray over four days, resulting in an overdose. A case report in the Journal of Pharmacy and Therapeutics said this caused her to have breathing problems, and her skin turned blue.

In 2018, the U.S. Food and Drug Administration (FDA) issued a warning that disclosed a link between benzocaine and methemoglobinemia in infants and children younger than two years. The FDA advised against over-the-counter oral benzocaine products being used in children under the age of two.

The FDA also announced a stronger warning about the risk of developing methemoglobinemia when using benzocaine. The agency estimated that over 400 patients developed methemoglobinemia after using benzocaine from February 2009 and October 2017.

In December 2023, Insight Pharmaceuticals recalled one lot of its Americaine 20% Benzocaine Topical Anesthetic Spray. This recall was due to the detection of benzene, a carcinogenic chemical. No serious adverse events were reported for this recalled product.

Benzocaine and lidocaine are both local anesthetics that have a numbing, pain-relieving effect. While lidocaine is more potent and longer-lasting than benzocaine, both medications share some common applications and risks.

Here’s how benzocaine and lidocaine compare.

Some benzocaine lawsuits allege that manufacturers failed to warn customers about life-threatening risks, including methemoglobinemia. Other cases are related to the improper marketing of benzocaine teething products to infants younger than two years of age.

The Judicial Panel on Multidistrict Litigation has not bundled any of these product liability lawsuits into a multidistrict litigation (MDL). MDLs consolidate multiple similar cases into a single case to expedite the legal process.

If you or your child developed methemoglobinemia after taking benzocaine, you may be eligible to file a lawsuit. Drugwatch can connect you with an experienced product liability attorney to determine if you have a case.

Multiple topical anesthetics are safe and effective alternatives to benzocaine. If you have a benzocaine allergy, you may be able to use several other topical anesthetics on the market.

For example, lidocaine is a similar but stronger medicine than benzocaine. Consequently, it needs a lower concentration to be effective.

However, not all versions of these medications are appropriate for every part of your body. There are many versions of local anesthetics, including creams, rinses and injections. Read the label thoroughly before using any new medications.

For pain relief from infant teething, doctors generally recommend drug-free alternatives. These include massaging the gums and using a firm rubber teething ring.

To get relief from mouth sore pain, a saltwater and baking soda rinse may be effective. The ideal ratio is one teaspoon of baking soda and one teaspoon of salt for every four cups of water.