Excerpted from: https://www.psychologytoday.com/us/blog/touchy-subject/201903/how-treat-body-focused-repetitive-behaviors
"Use of N-acetyl cysteine (NAC), a well-tolerated supplement available over the counter, has shown positive therapeutic effects on BFRB symptoms, particularly for adults with hair pulling and skin picking, and children and adolescents with nail-biting. NAC acts on glutamate, a neurotransmitter implicated in the brain’s reward system, which is believed to play a role in BFRB occurrence. Selective serotonin reuptake inhibitors and clomipramine may provide benefit for some, especially for those with co-occurring anxiety or depression. There is also some evidence to suggest Naltrexone, an opioid antagonist, may be beneficial in treating hair pulling for those who lack flexibility of thought and have a family history of alcohol or substance use. Olanzapine, an antipsychotic medication, has shown positive effects on hair pulling symptoms among adults."
References
Grant, J. E., Odlaug, B. L., & Kim, S. W. (2009). N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: A double-blind, placebo-controlled study. Achives of General Psychiatry, 66, 756-763.
Grant, J. E., Chamberlain, S. R., Redden, S. A., Leppink, E. W., Odlaug, B. L., & Kim, S. W. (2016). N-acetylcysteine in the treatment of excoriation disorder: A randomized clinical trial. JAMA Psychiatry, 73, 490-496.
Ghanizadeh, A., Derakhshan, N., & Berk, M. (2013). N-acetylcysteine versus placebo for treating nail biting, a double blind randomized placebo controlled trial. Anti-inflammatory & Antiallergy Agents in Medicinal Chemistry, 13, 223-228.
Grant, J. E. (2015). Review of psychopharmacological approaches for trichotillomania and other body-focused repetitive behaviors. Current Treatment Options in Psychiatry, 2, 422-431.
van Ameringen, M., Mancini, C., Patterson, B., Bennett, M., & Oakman, J. (2010). A randomized, double-blind, placebo-controlled trial of olanzapine in the treatment of trichotillomania. The Journal of Clinical Psychiatry, 71, 1336-1343.
https://psychiatry.uchicago.edu/news/what-new-research-telling-us-about-treating-bfrbs
N-acetyl cysteine (NAC)
https://www.bfrb.org/articles/n-acetylcysteine-for-trichotillomania-skin-picking-and-nail-biting
Grant, J. E., Odlaug, B. L., & Kim, S. W. (2009). N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: A double-blind, placebo-controlled study. Achives of General Psychiatry, 66, 756-763.
Grant, J. E., Chamberlain, S. R., Redden, S. A., Leppink, E. W., Odlaug, B. L., & Kim, S. W. (2016). N-acetylcysteine in the treatment of excoriation disorder: A randomized clinical trial. JAMA Psychiatry, 73, 490-496.
Ghanizadeh, A., Derakhshan, N., & Berk, M. (2013). N-acetylcysteine versus placebo for treating nail biting, a double blind randomized placebo controlled trial. Anti-inflammatory & Antiallergy Agents in Medicinal Chemistry, 13, 223-228.
Rodrigues-Barata, A. R., Tosti, A., Rodríguez-Pichardo, A., & Camacho-Martínez, F. (2012). N-acetylcysteine in the Treatment of Trichotillomania. International journal of trichology, 4(3), 176–178. https://doi.org/10.4103/0974-7753.100090
Lee, D. K., & Lipner, S. R. (2022). The Potential of N-Acetylcysteine for Treatment of Trichotillomania, Excoriation Disorder, Onychophagia, and Onychotillomania: An Updated Literature Review. International journal of environmental research and public health, 19(11), 6370. https://doi.org/10.3390/ijerph19116370
Sani, G., Gualtieri, I., Paolini, M., Bonanni, L., Spinazzola, E., Maggiora, M., Pinzone, V., Brugnoli, R., Angeletti, G., Girardi, P., Rapinesi, C., & Kotzalidis, G. D. (2019). Drug Treatment of Trichotillomania (Hair-Pulling Disorder), Excoriation (Skin-picking) Disorder, and Nail-biting (Onychophagia). Current neuropharmacology, 17(8), 775–786. https://doi.org/10.2174/1570159X17666190320164223
Kashetsky, N., Wong, A., Lam, J. M., Wong, S. M., & Mukovozov, I. M. (2023). Efficacy of N-acetylcysteine in trichotillomania (hair-pulling disorder), skin-picking disorder and onychophagia (compulsive nail-biting). Journal of the European Academy of Dermatology and Venereology : JEADV, 37(1), e73–e76. https://doi.org/10.1111/jdv.18508
Rothbart, R., & Stein, D. J. (2014). Pharmacotherapy of trichotillomania (hair pulling disorder): an updated systematic review. Expert opinion on pharmacotherapy, 15(18), 2709–2719. https://doi.org/10.1517/14656566.2014.972936