Trichotillomania Research Update: February 2019

Quick update!

Jon Grant and colleagues just published some new trichotillomania research this week and I wanted to post a quick summary and share my thoughts.


Milk Thistle Treatment for Children and Adults with Trichotillomania: A Double-Blind, Placebo-Controlled, Crossover Negative Study (1)

  • Supplement: Milk Thistle (Jarrow brand); contains silymarin, which has been used to protect the liver and has known antioxidant effects

  • Dosage: 150 mg 2x/day for 2 weeks; 300 mg 2x/day for 4 weeks

  • Study group: 16 adults & 4 children with trichotillomania (95% women)

  • Outcomes

    • Significantly less time spent pulling per day compared to placebo

    • A significant decrease in Clinical Global Impression (CGI) severity

    • A significant reduction in Massachusetts General Hospital Hair Pulling Scale (MGH-HPS) scores

    • 41.2% were “much or very much improved” after 6 weeks compared to placebo (31.3% improved)

    • No changes were seen in anxiety or depression symptoms

  • Side effects: well-tolerated, limited side effects; possible GI upset (reported in 20%)

My comments: Overall, to me this shows how milk thistle may be more effective than a placebo, but the sample size and improvement effect was far too small to conclude it as an effective treatment for everyone with trichotillomania. While they do show some significant improvements in hair pulling in those taking milk thistle compared to placebo, the amount of improvement was not that great. This isn’t your magic pill. In looking at the data, there were really only mild improvements compared to placebo—the equivalent of pulling your hair 15 minutes less per day and your clinician describing you as “mildly ill” versus “moderately ill”.

This was also just a really small study group, which included both adults and children, which have been known to respond to different types of treatments. It’s very possible that some people may respond better to milk thistle than others. Unfortunately, this study was too small to explore who may respond better than others. They’ll need to conduct follow-up studies in that regard.

My big question here is why someone might have a reduction in hair-pulling symptoms from taking milk thistle supplements. If someone is experiencing increased oxidative stress and increased free radicals, it’s possible they may benefit from milk thistle, but can we do better? Can we remove the source of oxidative stress in the first place to completely reverse the symptoms?

That brings me to our next study…


A Pilot Examination of Oxidative Stress in Trichotillomania (2)

I’m so glad that this study was done! We know that oxidative stress plays a role in most psychiatric conditions now and I’ve had a theory it plays a role in trichotillomania, too. This was more of an exploratory study, so there was no experimental treatment, but I think this is actually the more interesting study of the two because it explores subgroups of people that may be responding well to NAC treatment.

  • Study subjects: 14 participants (13 female, 1 male) with trichotillomania, 4 with comorbid depression, 4 with comorbid anxiety, 28.6% taking antidepressants

  • Oxidative stress markers collected: glutathione, angiotensin II, ferritin, iron, glucose, insulin and insulin growth factor 1 (IGF1), and hepcidin

  • Outcomes:

    • Glutathione levels were below normal for one-third of participants, which indicates oxidative stress

    • More oxidative stress (i.e., low glutathione levels) correlated significantly with higher motor impulsiveness (i.e., acting without thinking)

    • No significant findings for angiotensin II, ferritin, iron, glucose, insulin, IGF1, and hepcidin outside the normal reference range

My comments: There is quite clearly a subgroup with trichotillomania experiencing increased oxidative stress. I do wish they had used some other well-validated markers of oxidative stress (e.g., 8-OHdG, uric acid, bilirubin, GGT, MDA, etc.) but I think this was a good start. While it’s still only a hypothesis, it’s possible that those with increased oxidative stress may respond better to NAC and other treatments to reduce oxidative stress (topic for a future blog post).

OK so how do you know if you have oxidative stress? There are a few tests that a functional medicine practitioner can run to check for markers in blood and urine:

  • An Organic Acid Test (such as the Genova NutrEval) can look for:

    • 8-OHdG (in urine, high may indicate oxidative stress)

    • Glutathione (whole blood levels, like in the above study, where low levels may indicate oxidative stress)

    • Lipid Peroxides (in urine)

    • Coenzyme Q10 (in plasma)

  • Blood Chemistry tests

    • Comprehensive Metabolic Panel (this is a standard blood panel your doctor might order)

      • Bilirubin - low bilirubin may be an indicator of oxidative stress

      • Fasting glucose

      • Insulin

    • Uric acid, if low may also indicate oxidative stress


  1. Grant, J. E., Redden, S. A., & Chamberlain, S. R. (2019). Milk Thistle Treatment for Children and Adults with Trichotillomania: A Double-Blind, Placebo-Controlled, Crossover Negative Study. Journal Of Clinical Psychopharmacology. https://doi.org/10.1097/JCP.0000000000001005

  2. Grant, J. E., & Chamberlain, S. R. (2018). A Pilot Examination of Oxidative Stress in Trichotillomania. Psychiatry investigation, 15(12), 1130. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318485/