Novocaine: How it Works, Side Effects, and Alternatives

Clinical Content Reviewed by Dr. Jay Khorsandi, DDS
Last Modified:

Table of Contents

  1. Is My Dentist Using Novocaine?
  2. What Are Dentists Using?
  3. What Is Novocaine?
  4. How Long Does It Last?
  5. Risks & Side Effects
  6. History of Local Anesthetics
  7. How to Make It Wear Off More Quickly
  8. Frequently Asked Questions
  9. References

If you’ve ever been to the dentist and had a cavity filled or a tooth pulled and then walked out with your mouth feeling as if it is 10 times its normal size, you’ve probably experienced a dose of novocaine. And don’t even think about drinking water because, well, you know what can happen.

You probably think you know all you need to know about novocaine, but in fact, the more you know the better you will understand how and why it works. Join us as we explore this once popular and valuable anesthetic.

Is My Dentist Numbing My Mouth with Novocaine?

Decades ago, novocaine was the preferred option, but dentists now use other forms of anesthesia that last longer, work better, and cause fewer side effects.

What Are Dentists Using?

There are three types of dental anesthesia: local, topical, and general. Topical anesthesia comes in the form of jelly or gel applied to an area that needs numbing. This usually precedes the injection of local or general anesthesia.

Local anesthesia deactivates nerves. Lidocaine and prilocaine are the most popular form of local anesthesia currently. It is most likely your dentist is using it when preparing you for a surgery.

Of those, lidocaine is the most common with dentists using this for fillings, root canals, and extractions. General anesthesia renders patients completely unconscious. It is unlikely that your dentist will use this unless it is a major dental procedure.

There are three types of sedation, including inhalation, oral, and IV. Sedation helps calm patients, and dentists easily control the amount administered.

What Is Novocaine?

Novocaine is a local anesthetic that is injected to numb a part of the body. The drug causes a loss of feeling to the skin and mucous membranes. Medical practitioners use novocaine to numb patients and prevent pain during surgery or dental procedures.

How Long Does Novocaine Last?

Patients typically encounter the numbing effects for about an hour or two after their procedure. However, it is common to feel the side effects for up to half a day after your dental appointment.

How long novocaine lasts depends on:

  • The number of nerves being blocked by the numbing agent

  • Type of procedure performed

  • How long the procedure will last

  • Size of the area under treatment

Risks and Side Effects

The local anesthesia generally does not have significant side effects aside from the numbness. Still, people can have reactions to of novocaine, and they include:

This is the only side effect that patients want. You can expect to feel numbness setting in after one or two shots. It has the simple purpose of allowing the dentist to work on an area with minimal discomfort to the patient. The anesthesia may affect your cheek and eye area, causing tingles and a slight droop. These effects wear off after a while.

If the dentist accidentally hits a blood vessel, you may develop a hematoma or bruise. It is a slight swelling in the gum filled with blood. It is harmless and tends to go away on its own.

This is a common side effect, especially if you had a shot to the upper gums. If you find it hard to blink, the dentist may use a special tape to keep the eye shut to prevent it from drying out.

Novocaine may cause vasoconstriction, or a temporary narrowing of the blood vessels, that may last for a minute or two after the injection. Be sure to tell your dentist if you experience this side effect.

Patients may experience tingling, pain, or numbness lasting weeks or months in rare cases. That is typically a result of nerve damage during the procedure.

History of Local Anesthetics

Local anesthetics started in 1884 with organic cocaine used to assist in an eye surgery. Practitioners continued using cocaine as local and regional anesthesia through the country. Soon, addiction and deaths followed the use, forcing a shift to pure cocaine in 1891.

Further developments gave rise to amino ester anesthetics such as eucaine, tropocaine, and benzocaine that came to prominence from 1891 until 1930. Similarly, amino amide local anesthetics such as novocaine, nirvaquine and lidocaine grew popular from 1898 to 1972.

Another significant development was the introduction of bupivacaine in 1957. However, it brought about cardiovascular (CV) and central nervous system (CNS) toxicity. Further research resulted in ropivacaine, introduced to the market in 1996. It has limited side effects.

How to Wear Off Novocaine More Quickly

Even though you escaped the pain of the dental procedure, facing the lingering numbing effects of novocaine can be a challenge. Typically, the numbing effect of novocaine takes about one to two hours to wear off, but you may still experience side effects up to five hours after an injection.

Here are some ways you can help the novocaine wear off more quickly:

  • Massage the area to increase blood flow. If you do not have pain and swelling after the procedure, gently use your fingers to massage around the site. Increased blood flow helps bring back feeling. Make sure your hands are clean before touching your mouth or face.

  • Use a warm compress. This is another way to increase blood flow to the area, helping the novocaine wear off more quickly.

  • Try some mild physical activity. If your dentist approves it, engage in light exercises like walking or riding a bike. This gets your blood pumping and flowing to the injection site, decreasing the effects of the anesthesia.


It is a common misconception that novocaine is still the numbing agent of choice for dentists. However, dentists prefer septocaine and lidocaine over novocaine nowadays. Dentists stopped using novocaine because of the length of time it takes to work and the risks of allergic reactions.

Novocaine takes longer to kick in, thus lengthening your dental appointment. Furthermore, this anesthesia wore off quickly, leaving dentists with a short operating window to perform the procedures. Also, this medicine can cause an allergic reaction in some patients.

Dentists turned to lidocaine and septocaine, which work faster, last longer, and have minimal side effects.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.