Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Scalp scaling
RCT 3-armed trial	246 people with moderate to severe dandruff	% Reduction in mean adherent dandruff score from baseline 29 days 66.7% with selenium sulphide 2.5% shampoo 44.5% with placebo (shampoo base without selenium sulphide) Absolute numbers not reported	Reported as significant P value not reported	Effect size not calculated	Selenium sulphide
Global severity
RCT 3-armed trial	246 people with moderate to severe dandruff	Proportion of people responding to treatment (global evaluation of completely cleared, excellent, or good) 29 days 54.7% with selenium sulphide 2.5% shampoo 28.6% with placebo (shampoo base without selenium sulphide) Absolute numbers not reported	P = 0.004	Effect size not calculated	Selenium sulphide