Molecule of the Day

Eugenol (Mmm, dentist)

Eugenol is a substance found in cloves. In addition to the distinct aroma of cloves, it’s responsible for the numbness that clove oil can induce (dentists often swab your gums with it before giving you an injection of novocaine or lidocaine):

Sharp readers will notice the similarity to vanillin. The aromatic nucleus behind both these molecules is guaiacol.

Eugenol is one of those natural products that is sufficiently abundant it can be recovered by steam distillation (PDF).


  1. #1 Glenn Branch
    October 4, 2006

    Is it safe?

  2. #2 MoTD
    October 4, 2006

    Safe beyond the relatively rare allergy, as far as I know. It has a long tradition of use as an anaesthetic (and is found in many OTC preps, as either eugenol, or “clove oil”).

  3. #3 Markk
    October 4, 2006

    MoTD, “Is it safe?” was Laurence Olivier’s question in Marathon Man in the role of the Nazi dentist torturing Dustin Hoffman by drilling his teeth and using Oil of Cloves to stop the pain… one of the great movie villains and an excellent William Goldman movie. It was also the first thing that came into my mind when I saw Oil of Cloves along with a shiver. Recommended movie.

  4. #4 Julie Stahlhut
    October 5, 2006

    About thirty years ago, my dentist placed a clove oil pack in my mouth after a particularly painful procedure. I already had a mild dislike of cloves (they were my mother’s favorite spice and perhaps my least favorite). It quickly became a strong dislike. I’ll eat things with cloves in them, but it’s one of the few ground spices that I never actually buy or use at home.

    My husband also attempted to settle down a toothache with clove oil while awaiting a dental appointment. He used the clove oil full strength and wound up with a burn on his gums that was more painful than the toothache.

  5. #5 Dave Eaton
    October 16, 2006

    I’ve seen in the literature eugenol being used as both an attractant for some species of spiders and a repellant for others. I wonder if its similarity to neurotransmitters is the reason.

    One of my Indian colleagues chews cloves now and then, once when I was working with eugenol. Alhough I knew what was going on, was disturbing to have a friend with breath like a compound I was using.

  6. #6 jalal jafar
    December 21, 2006

    ho is eugenol relif the dental pain i mean what is the mechanism of action

  7. #7 bDubL
    March 8, 2007

    i’m going to go and suck on a bag of cloves… can I expect to get high?

  8. #8 lalit kumar
    February 8, 2008

    eugenol is the main constitutent in the ocimum sanctum( holy basil).

  9. #9 Aga
    February 25, 2008

    Four of my friends had uterus cancer operation. All of them look like 25/30 at real age 40/50. Two of them are working as technicians making dentures, one was working with some chemical. As I see some similarities,I\m trying to figure out what caused cancer and their young appereance. I smell eugenol in it as a main factor. Am I right?

  10. #10 Edward Cheung
    March 30, 2008

    Eugenol shares a chemical similarity to Capsaicin, which is the pungent constituent of chilli peppers that gives rise to the burning pain associated with eating chilli peppers. Believe it or not, despite the fact that clove oil is incorporated into many dental medicaments, its exact mechanism of action is still not known. Current scientific literature has suggested that Eugenol acts on Vanilloid receptor 1 (VR1), this is due to the fact that eugenol’s mechanism of action is inhibited by capsazepine (VR1 antagonist). VR1 are the receptors located on nociceptors; these are the receptors that are responsible for pain sensation, thus blocking these receptors results in the inhibition of pain sensation.

    A note to make on Eugenol is that it is associated with carcinogenicity due to structural similarity with alkenylbenzen.(classed as possible carcinogenic to humans by the International Agency for Research on Cancer). The eugenol derivative, methyleugenol has also been classed as highly carcinogenic by the International Agency for Research on Cancer.

    The exact mechanism of Clove oil and its major constituents, Eugenol, methyleugenol and beta-carryophyllene are still under major scientific study.

  11. #11 Tjalfe of Denmark
    April 24, 2008

    Eugenol is quite safe.. Not only is it used by dentist as momentarily toothfilling (combined Zinkoxide)and local anaesthetics. Cloves has been used in China for hundreds of years and the region there about to cleanse teeth and to take away the pain in case of toothacne.. I tried some my self it didn’t taste good at all but it did take away my bad morningsbreath and my toungue became a little numb.

  12. #12 jonalyn lelis
    October 29, 2008

    base on my knowledge,it is safe and can help us in many ways.all things have theire own disadvantage so if your allergic in perfumes it is better not to use it.

  13. #13 Robert
    June 1, 2009

    Is Eugenol a Therpen? Why? Thanks

  14. #14 Richmond Hill Dentist
    June 26, 2009

    This is an old remedy used in the past that actually works

  15. #15 Dentist Richmond Hill
    July 26, 2009

    Eugenol is used in temporary dental fillings by dentists to relieve tooth pain.

  16. #16 la habra dentist
    December 10, 2009

    it is a good remedy for toothache although it is not good in taste, but a pretty nifty for dentist.

  17. #17 Morgan
    March 21, 2010

    I suggest you see for toxicity concerns. Also note that cloves and eugenol are two different things. Just because eugenol is found in cloves and other herbs doesn’t mean that you can safely use it the way you would those herbs! In response to Tjalfe of Denmarkcloves, though cloves have been used to treat ailments throughout history, they are also toxic in high doses.

  18. #18 LaRufus Roosevelt Franklin
    February 3, 2011

    I lost my dental insurance and think I developed a cavity. The pain was unbearable and I was popping ibuprofen like candy. Finally, I purchased this Red Cross Toothache Kit which contained cotton pellets and eugenol. Yes, the taste is gross and it might burn/numb your lips/tongue but after a few applications, my pain has disappeared and it has been two weeks! Amazing…

  19. #19 espansione crestale
    April 18, 2012

    Eugenol have the capacity to cause adverse effects but has a long history of successful therapeutic use in dentistry.

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