N-Acetylcysteine in the treatment of pediatric trichotillomania: a randomized, double-blind, placebo-controlled add-on…
NAC worked in adults with hair-pulling but not in children — if this is for my child, what does the evidence actually support us doing first?
Well-supported by good-quality research. how we score evidence
Caveat on this rating: A 39-person trial has limited power, and the authors discuss whether the frequent study visits and psychoeducation inflated the placebo response — so this is a failed replication rather than proof that NAC does nothing in children. It is included precisely because the positive adult trial is usually cited without it.
NAC sits in an unusual place.
39 children and adolescents aged 8-17 with trichotillomania were randomised to NAC or matching placebo for 12 weeks. There was no significant difference on any primary or secondary outcome: 25% of the NAC group were judged responders versus 21% on placebo, and both groups improved with time regardless of assignment. The authors, who included the first author of the positive adult trial, state plainly that the finding "stands in contrast" to that trial and conclude that children with trichotillomania should be referred for behavioural therapy before any medication is started.
Worth asking
NAC worked in adults with hair-pulling but not in children — if this is for my child, what does the evidence actually support us doing first?
Source
N-Acetylcysteine in the treatment of pediatric trichotillomania: a randomized, double-blind, placebo-controlled add-on trial. — Bloch MH, Panza KE, Grant JE, Pittenger C, Leckman JF. (2013)
Reputable peer-reviewed journal
Read the source: https://doi.org/10.1016/j.jaac.2012.12.020
DOI: 10.1016/j.jaac.2012.12.020
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Independently funded
- Published in
- Reputable peer-reviewed journal
- Sample size
- 39
- Preregistered
- Yes
- Conflicts disclosed
- Yes
- Independent of proponent
- Yes
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 19, 2026.
Where we put this study in context
Questions
How strong is the evidence behind this?
Resolv rates this source "strong evidence". Well-supported by good-quality research. It scores 84 out of 100 on our published rubric. One caveat travels with that badge: A 39-person trial has limited power, and the authors discuss whether the frequent study visits and psychoeducation inflated the placebo response — so this is a failed replication rather than proof that NAC does nothing in children. It is included precisely because the positive adult trial is usually cited without it. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
N-Acetylcysteine in the treatment of pediatric trichotillomania: a randomized, double-blind, placebo-controlled add-on trial. — Bloch MH, Panza KE, Grant JE, Pittenger C, Leckman JF. (2013). Published in: Reputable peer-reviewed journal. DOI: 10.1016/j.jaac.2012.12.020. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Independently funded. The researchers were independent of whoever benefits from the result. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is nac, n-acetylcysteine, n-acetyl-l-cysteine, acetylcysteine, acetadote, mucomyst FDA approved for this use?
No. Its current status is: Not FDA-evaluated for this use. NAC sits in an unusual place.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.