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Breaking the Nail-Biting Habit

People who would like to drop their nail-biting habit may want to consider taking N-acetyl cysteine. This supplement seems to be helpful.
Breaking the Nail-Biting Habit
Young Caucasian woman staring and biting her fingernail

As many as 30 percent of American adults have a nail-biting habit, and probably quite a few of them would like to break it. Have you ever tried to do that? It may not be as tough as breaking an addiction like smoking, for example, but it can be far from easy. How do people stop biting their nails?

Help for a Nail-Biting Habit:

Q. I have been feeling very anxious about being stuck at home because of the coronavirus. All the stress has led me to start biting my nails again. My thumbs look awful and my wife gives me a lot of grief about them.

I have sometimes used instant glue to stop myself from chewing on the rough spots. I figure that it’s not healthy to swallow the dried glue. Do you have any other ideas about how to overcome my horrible nail-biting habit?

A. Biting your nails is a particularly bad habit when you are trying to avoid infection with COVID-19. No amount of preaching about keeping your hands away from your face (and your fingers out of your eyes, nose and mouth) will give you the willpower to just stop cold turkey. Neither will the impressive name doctors call it: onychophagia.

NAC to the Rescue:

However, Australian scientists may have come up with a promising aid almost by accident. According to The Wall Street Journal (Dec. 28, 2020), they were testing a nutraceutical, N-acetyl cysteine (NAC), for its ability to help people with bipolar disorder.  Unexpectedly, a few of the people in the study stopped biting their nails while they were taking the supplement (CNS Spectrums, Nov. 7, 2014).  It may be helpful against other obsessive grooming behaviors such as hair pulling as well (Clinical Neuropharmacology, Jul/Aug 2019).

A randomized controlled trial found that NAC was more effective than placebo in helping youngsters stop biting their nails (Anti-inflammatory & Anti-allergy Agents in Medicinal Chemistry, 2013).  The study was small, however. We’d really like to see more research before we become overly enthusiastic. NAC is inexpensive and safe, so you might want to give it a try. Let us know how it works for you.

Other Approaches to Overcoming Nail Biting:

NAC is not the only solution nail biters have tried. We heard from another reader years ago desperate for help.

Q. I have bitten my fingernails for years. I’ve stopped several times for as long as six months, but just like a smoker, I can’t kick the habit for good.

The biggest problem is when I’m reading, watching TV or driving. It leaves my fingers and cuticles ugly and very sensitive. How can I quit?

A. There are surprisingly few well-controlled studies of treatments for nail biting. Many health professionals view this habit as a manifestation of obsessive-compulsive disorder. Some data suggest that cognitive behavioral therapy could be effective (Dermatologic Therapy, Nov. 2020). Therapy aimed specifically at habit reversal has shown the most promise. If the nail biter has other signs of OCD, the therapist may also prescribe an SSRI such as fluoxetine. 

Over-the-counter approaches involve painting bitter-tasting substances on the nails to remind the person to stop biting. They include products such as Mavala Stop or Control-It!, with denatonium. Some people also find that clear nail polish helps as a different type of reminder to give up the nail-biting habit.

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About the Author
Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies. .
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  • Berk M et al, "Nail-biting stuff? The effect of N-acetyl cysteine on nail-biting." CNS Spectrums, Nov. 7, 2014. DOI: https://doi.org/10.1017/S1092852900023002
  • Ghanizadeh A et al, "N-acetylcysteine versus placebo for treating nail biting, a double blind randomized placebo controlled clinical trial." Anti-inflammatory & Anti-allergy Agents in Medicinal Chemistry, 2013. DOI: 10.2174/1871523011312030003
  • Skurya J et al, "Habit reversal therapy in the management of body focused repetitive behavior disorders." Dermatologic Therapy, Nov. 2020. DOI: 10.1111/dth.13811
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