Benzocaine is generally considered low-risk during pregnancy when used topically and as directed. Very little of the drug is absorbed into the bloodstream through skin or mucous membranes, which means the amount that could reach a developing fetus is minimal. That said, benzocaine has never been formally studied in pregnant humans through controlled trials, so no major medical organization gives it an unconditional green light.
What the Evidence Shows
Benzocaine is classified as a former FDA pregnancy category C drug, meaning animal reproduction studies were never performed and there isn’t enough human data to confirm or rule out risk. What does exist is reassuring: two reports that looked at women who used benzocaine during the first trimester found no greater chance of birth defects compared to women who didn’t use it.
The key reason benzocaine is considered relatively safe is how little gets into your system. Your skin and the lining of your mouth act as barriers, so only a small fraction of the medication reaches your bloodstream. According to MotherToBaby, a service of the Organization of Teratology Information Specialists, the amount that can reach a developing fetus through topical absorption is usually much lower than with medications taken by mouth. When used as directed, it’s unlikely that a significant amount would reach the fetus, and the chance of birth defects or other complications is expected to be low.
There are situations where more benzocaine gets absorbed: broken or irritated skin, open sores in the mouth, or application over a large area. If you’re using it on intact skin or a small patch of gum tissue, absorption stays very low.
The Methemoglobinemia Concern
The most serious risk of benzocaine for anyone, pregnant or not, is a rare blood condition called methemoglobinemia. This happens when benzocaine changes the iron in your red blood cells so they can no longer carry oxygen efficiently. In 2018, the FDA issued a warning about this risk for oral benzocaine products used for mouth and teething pain.
For pregnant women, this risk carries an added layer of concern. If methemoglobinemia does develop, the standard treatment is a medication called methylene blue, which is considered dangerous to a developing fetus. One published case involved a 35-year-old woman at 20 weeks of pregnancy who developed methemoglobinemia during an oral surgery procedure involving local anesthetic. Her blood oxygen-carrying capacity dropped significantly, with 34.7% of her hemoglobin unable to transport oxygen. The medical team faced a difficult choice because the treatment itself posed fetal risks.
This scenario is extremely rare with normal over-the-counter use. It’s primarily a concern with large doses, repeated applications, or medical procedures where benzocaine is applied to large areas of tissue. A single application of an OTC throat spray or a dab of oral pain gel carries very low risk of triggering this reaction.
Common Uses During Pregnancy
Most pregnant women asking this question are dealing with one of a few specific problems: a sore throat, a toothache, or hemorrhoids. The safety picture looks slightly different for each.
For mouth and throat pain, benzocaine lozenges and sprays apply the drug directly to mucous membranes. Mucous membranes absorb more than intact skin does, but the amounts in OTC products are small. A single lozenge or a few sprays used occasionally is unlikely to cause problems. Avoid using these products repeatedly throughout the day or for extended periods.
For hemorrhoid creams containing benzocaine, the skin in the rectal area can be irritated or broken, which increases absorption. MotherToBaby notes that more active ingredient reaches the bloodstream when skin is damaged or when it’s applied over a large area. Using a small amount on external hemorrhoids as directed is considered low-risk, but keep applications brief and infrequent.
For dental procedures, dentists sometimes apply benzocaine gel to numb the gums before injecting a local anesthetic like lidocaine. This is a one-time, small-area application and is widely considered safe during pregnancy. Dental care during pregnancy is important, and the American Dental Association supports routine dental treatment throughout pregnancy.
Ways to Reduce Your Need for Benzocaine
If you’d rather avoid benzocaine entirely, several alternatives can help with common sources of pain during pregnancy.
- Warm saltwater rinse: Dissolving half a teaspoon of salt in warm water and gargling or swishing can reduce inflammation and kill bacteria in the mouth. This works for sore throats and mild toothaches.
- Cold compress: Holding a cold pack against the outside of your cheek numbs the area and reduces swelling from dental pain.
- Clove oil: A small amount of diluted clove oil dabbed on a cotton ball and placed against a sore tooth provides temporary numbing. It contains a natural anesthetic compound. Use it sparingly and check with your dentist before repeated use.
- Ice chips or cold fluids: For sore throats, cold temperatures naturally reduce pain and inflammation without any medication.
These remedies offer temporary relief. They won’t replace professional treatment for a dental infection or severe pain, but they can help you avoid reaching for benzocaine when the discomfort is manageable.
How to Use Benzocaine More Safely
If you do choose to use benzocaine during pregnancy, a few practical steps can minimize any risk. Apply the smallest amount that relieves your pain. Don’t reapply more frequently than the label directs. Avoid using it on broken skin or open wounds where absorption will be higher. And stick to products with lower concentrations of benzocaine when possible.
The first trimester is when fetal organs are forming and sensitivity to outside substances is highest. The limited evidence available did not find increased birth defect risk from first-trimester use, but many women prefer to be most cautious during those early weeks. By the second and third trimesters, the major structures have formed and the risk from minimal topical absorption drops further.
If you’re using benzocaine and notice any unusual symptoms like bluish or grayish skin, dizziness, rapid heartbeat, or shortness of breath, stop using it and seek medical attention. These are signs of methemoglobinemia, and while the chance is very small, pregnancy makes it more urgent to catch early.