• Dental Phobia Support

    Welcome! This is an online support group for anyone who is has a severe fear of the dentist or dental treatment. Please note that this is NOT a general dental problems or health anxiety forum! You can find a list of them here.

    Register now to access all the features of the forum.

Novacaine Side Effects



Well-known member
Mar 9, 2022
Hi all! So I wanted to talk about novacaine side effects. I have had 3 root canals in my life and have had to be numbed. Every time I get novacaine injections, I get EXTREMELY shaky and my heart races, and stays that way for a while after the procedure. I have heard before that this is normal because the novacaine (at least here in the US) contains epinephrine. I already have a higher rate due to anxiety and nerves, so my heart is usually already elevated. My fear is that because I am already uneasy, my heart rate getting so high and remaining high will make me sick or faint, because that's how I start to feel. I am afraid that something extreme will happen to my body, like a heart attack or something extreme. And again, it's because of how it feels physically. Do our bodies just metabolize the novacaine and it can basically withstand that response? I just worry so much about this and it's truly the ONLY reason why I feel being in the dental chair. They also said they have to use novacaine that contains the epinephrine to do the nerve block on the bottom.
Novocaine was discontinued just after WW2... just saying :)

There are various different local anaesthetic solutions available, some of which have epinephrine and some don't. IMO, there's no particular reason why a block injection requires epinephrine.

Most of the time when we get a response like you describe it's because a little bit of the LA solution was accidentally injected into a vein, this can be mostly avoided by careful technique by the dentist but occasionally accidents will happen.

Yes your body happily will metabolise both the LA solution and the epinephrine.
@Gordon OHHHH! That makes sense. I had no idea.

The endodontist said the solution with epi is needed to do a total nerve block. It seems that their choice of numbing solution. Should I ask again? I don't want to bother them with my anxiety but it is such an unpleasant feeling and hard to sit through.

Thank you!
No harm in asking them, as I said, plenty of alternative drugs available. Although unless you're very unlucky you should be fine with the standard local + epi combination.