--- title: "Nitrous Oxide at the Dentist: Side Effects and Safety" description: "What are the side effects of nitrous oxide (laughing gas) at the dentist? Learn how it feels, how fast it wears off, rare risks, and what to tell the dentist." url: https://towncenterdental.multisites.ai/blog/nitrous-oxide-at-the-dentist-side-effects-and-safety publisher: Town Center Dental phone: +1-636-273-5866 quote: https://towncenterdental.multisites.ai/request-appointment --- # Nitrous Oxide at the Dentist: Side Effects and Safety Nitrous oxide, or laughing gas, is a gas you breathe through a small nose mask to help you relax. You stay awake. You may feel light-headed or have tingling, and the effects wear off soon after the mask is removed. Vomiting is the most common reported side effect. Tell your dentist about your health first. Comfort and anxietyPublished October 26, 20264 min read ## What is nitrous oxide, and how does it work at the dentist? Nitrous oxide, often called laughing gas, is a gas you breathe through a small mask over your nose. The American Dental Association (ADA) says it is mixed with oxygen and helps you relax. It is one option your dentist may offer to help make you more comfortable during certain procedures. You stay awake. The ADA says it is not intended to put you to sleep, and you can hear and respond to your dentist. Your dentist asks you to breathe normally through your nose. Within a few short minutes you should start to feel the effects. Learn more about [nitrous oxide](https://towncenterdental.multisites.ai/glossary/nitrous-oxide-laughing-gas) in our glossary. Town Center Dental describes its own use of nitrous oxide on its [sedation dentistry](https://towncenterdental.multisites.ai/services/sedation-dentistry) page. ## What happens during the visit, step by step? Based on the ADA description, a visit with nitrous oxide goes like this: 1. A small mask is placed over your nose. 2. You breathe normally through your nose. 3. Within a few short minutes, you start to feel the effects. 4. You stay awake and can answer your dentist. 5. When the dental work is done, the mask is removed. 6. The effects wear off soon after. ADA guidance for offices adds that patients should be encouraged to breathe through the nose and limit talking while the gas is in use. Ask your dentist if you have questions about what the visit will feel like. ## What does it feel like? The ADA says you may feel light-headed or have a tingling in your arms and legs. Some people say their arms and legs feel heavy. Ultimately, you should feel calm and comfortable. The ADA also says the effects wear off soon after the mask is removed. Ask your dentist whether numbing medicine, called a [local anesthetic](https://towncenterdental.multisites.ai/glossary/local-anesthetic), will also be used for your visit. Your dentist explains which steps the work needs. ## What are the side effects? Most reports describe short effects that fade after the gas stops. The table lists what the sources say. Effect What the source says Light-headed feeling, tingling, heavy arms and legs The ADA lists these as normal feelings during use Vomiting A peer-reviewed review says it is the most common adverse event reported with nitrous oxide sedation Low oxygen right after the gas stops The review says there is a risk of diffusion hypoxia after stopping, which may be minimized by giving 100% oxygen afterward Low vitamin B12 problems The review says nitrous oxide can irreversibly inactivate vitamin B12; it calls this rare, and says it can be fatal in some patients The review covers procedural sedation in general, not only dental visits, so treat its figures as a rough guide, not a number for any one office. ## What does the evidence say about safety? The review looks at both the benefits of nitrous oxide and the adverse events linked to it. It says the rare vitamin B12 problem should not be underestimated. If screening is possible before use, it says a suitable alternative sedative would be preferable for people at risk. That is why the health history you give matters. Tell your dentist about: - Any known vitamin B12 problem or related condition - Pregnancy, or the chance of pregnancy - Past reactions to gas or sedation - Nausea or a recent meal, if the office asks - Every medicine you take The ADA says to talk to your dentist about whether nitrous oxide would be a good option for you. A sedative is a medical decision, so let your dentist make it with you. ## Why is oxygen given at the end? The review says there is a risk of diffusion hypoxia after nitrous oxide stops. It says the risk may be minimized when 100% oxygen is supplied after the gas is stopped. ADA guidance for offices also lists delivering 100% oxygen for five minutes after the procedure is over and before removing the mask. This is routine in many offices. Ask your dentist what steps the office follows. ## What about pregnancy? Pregnancy needs a special conversation. The ADA says that while nitrous oxide can be beneficial, pregnant women should avoid exposure because of the possibility that it can harm the developing fetus. That page is written for dental staff and patients. Tell the office if you are, or may be, pregnant, and talk with your obstetrician too. Read our post on [dental work during pregnancy](https://towncenterdental.multisites.ai/blog/dental-work-during-pregnancy) for more. ## Why do dentists use it? The review calls nitrous oxide an odorless and colorless gas that is very appealing as a sedative. It lists calming, pain-relieving, and memory-dulling effects, quick onset and recovery, and, in particular, application without a needle. In plain words, it can help ease [dental anxiety](https://towncenterdental.multisites.ai/glossary/dental-anxiety), starts working fast, and fades fast. Whether it fits you depends on your health and the work planned. If dental fear keeps you from care, start with the office’s page on [dental anxiety management](https://towncenterdental.multisites.ai/services/dental-anxiety-management). Our guides on [sedation dentistry](https://towncenterdental.multisites.ai/guides/sedation-dentistry-guide) and [dental anxiety](https://towncenterdental.multisites.ai/guides/dental-anxiety-guide) explain the choices in plain words. ## What should I ask before my visit? A few questions can make the visit easier: - Will I need numbing medicine too? - How will I feel right after the mask comes off? - Should I eat before the visit? - Is there anything in my health history that changes the plan? - What should I watch for afterward? Write down the answers and keep them with your appointment details. ## Next step To ask whether nitrous oxide may fit your visit, read the office’s [sedation dentistry](https://towncenterdental.multisites.ai/services/sedation-dentistry) page. Then call Town Center Dental at (636) 273-5866 or [request an appointment](https://towncenterdental.multisites.ai/request-appointment). Your dentist will talk with you about what to expect. ## Frequently asked questions ### What does nitrous oxide feel like? The ADA says you may feel light-headed or have a tingling in your arms and legs. Some people say their arms and legs feel heavy. Ultimately you should feel calm and comfortable. You stay awake and can hear and respond to your dentist. ### How long does nitrous oxide last? The ADA says the effects wear off soon after the mask is removed. A published review describes rapid onset and rapid recovery as key features of the gas. Your dentist will tell you what to expect after your visit. ### What are the side effects of nitrous oxide? A review in a peer-reviewed journal says vomiting is the most common adverse event reported with nitrous oxide sedation. Other effects are described in the table in this post. Tell your dentist about nausea, your health history, and any past reactions. ### Can I have nitrous oxide if I am pregnant? Talk with your dentist and your obstetrician first. The ADA says that pregnant women should avoid exposure to nitrous oxide because of the possibility that it can harm the developing fetus. Tell the office if you are or may be pregnant. ## Terms on this page - [Nitrous oxide (laughing gas)](https://towncenterdental.multisites.ai/glossary/nitrous-oxide-laughing-gas) - [Numbing (dental numbness)](https://towncenterdental.multisites.ai/glossary/numbing-dental-numbness) - [Local anesthetic](https://towncenterdental.multisites.ai/glossary/local-anesthetic) - [Dental anxiety](https://towncenterdental.multisites.ai/glossary/dental-anxiety) ## Sources 1. [American Dental Association (MouthHealthy): Nitrous Oxide - Laughing Gas](https://www.mouthhealthy.org/all-topics-a-z/nitrous-oxide) 2. [American Dental Association (MouthHealthy): Nitrous Oxide - Laughing Gas](https://www.mouthhealthy.org/all-topics-a-z/nitrous-oxide) 3. [American Dental Association (MouthHealthy): Nitrous Oxide - Laughing Gas](https://www.mouthhealthy.org/all-topics-a-z/nitrous-oxide) 4. [American Dental Association (MouthHealthy): Nitrous Oxide - Laughing Gas](https://www.mouthhealthy.org/all-topics-a-z/nitrous-oxide) 5. [American Dental Association (MouthHealthy): Nitrous Oxide - Laughing Gas](https://www.mouthhealthy.org/all-topics-a-z/nitrous-oxide) 6. [PMC (peer reviewed): Complications caused by nitrous oxide in dental sedation](https://pmc.ncbi.nlm.nih.gov/articles/PMC5932993/) 7. [PMC (peer reviewed): Complications caused by nitrous oxide in dental sedation](https://pmc.ncbi.nlm.nih.gov/articles/PMC5932993/) 8. [PMC (peer reviewed): Complications caused by nitrous oxide in dental sedation](https://pmc.ncbi.nlm.nih.gov/articles/PMC5932993/) 9. [PMC (peer reviewed): Complications caused by nitrous oxide in dental sedation](https://pmc.ncbi.nlm.nih.gov/articles/PMC5932993/) 10. [American Dental Association: Nitrous Oxide Safety for Pregnant Dental Staff and Patients](https://www.ada.org/resources/practice/practice-management/nitrous-oxide-safety-for-pregnant-dental-staff-and-patients) 11. [American Dental Association: Nitrous Oxide Safety for Pregnant Dental Staff and Patients](https://www.ada.org/resources/practice/practice-management/nitrous-oxide-safety-for-pregnant-dental-staff-and-patients) 12. [American Dental Association: Nitrous Oxide Safety for Pregnant Dental Staff and Patients](https://www.ada.org/resources/practice/practice-management/nitrous-oxide-safety-for-pregnant-dental-staff-and-patients) Written by Town Center Dental and checked against the sources above on October 26, 2026. Dental guidance changes, so check the linked page, and ask your dentist about your own care. ## Keep reading - [Sedation Dentistry: How Safe Is It, and Which Type Fits Your Visit?Sedation dentistry uses medicine to help you feel calm during dental care. Common types are nitrous oxide, oral sedation, IV sedation and general anesthesia. Missouri requires a state permit for dentists who give deeper levels. Town Center Dental describes its own sedation care on its sedation page. Your dentist will talk with you about what fits you.](https://towncenterdental.multisites.ai/guides/sedation-dentistry-guide) - [Dental Work During Pregnancy: What ADA and ACOG SayThe ADA and ACOG both say dental care is an important part of prenatal health. The ADA says routine care, X-rays, and local anesthesia are considered safe at any point in pregnancy. Tell your dental team you are pregnant and share your due date. Your dentist and obstetrician can answer personal questions.](https://towncenterdental.multisites.ai/blog/dental-work-during-pregnancy) - [Dental Anxiety: 12 Ways to Make the Visit EasierDental anxiety is a common fear of dental visits. Cleveland Clinic says about 36% of people in the U.S. fear dental treatment. You can ease it by telling the team, agreeing on a stop signal, using relaxation, and asking about options such as nitrous oxide. Your dentist will talk with you about what fits.](https://towncenterdental.multisites.ai/guides/dental-anxiety-guide) - [Your Child's First Dental Visit: When To Start, What To Expect, and When Teeth Come and GoThe ADA and the AAP say to schedule your child's first dental visit after the first tooth appears and no later than the first birthday. Most visits are short. The dentist checks the teeth and gums, talks about cleaning and habits, and plans future check-ups. Baby teeth start to come in around 6 months.](https://towncenterdental.multisites.ai/guides/childs-first-dental-visit) - [Dental Emergencies: What Counts, What To Do First, and Who To CallA dental emergency is a mouth problem that needs care right away, such as uncontrolled bleeding, severe pain that medicine does not ease, or a knocked-out tooth. Call 911 or go to an emergency room for trouble breathing or swallowing. Otherwise, call your dentist. Town Center Dental is closed Friday to Sunday.](https://towncenterdental.multisites.ai/guides/dental-emergency-guide) - [Dental Insurance Explained: Deductibles, Maximums and NetworksDental insurance usually has a monthly premium, a deductible you pay first, coinsurance or copays after that, and a yearly maximum the plan will pay. PPO plans give you more dentist choice than dental HMOs. Waiting periods, frequency limits and exclusions decide what is paid, so read the plan before treatment.](https://towncenterdental.multisites.ai/guides/dental-insurance-explained) ## Ready when you are [Request an appointment](https://towncenterdental.multisites.ai/request-appointment)[Call (636) 273-5866](tel:+1-636-273-5866)