The Antidandruff Efficacy of Head and Shoulders Rinse-in-Shampoo (1% Zinc Pyrithione) and Head and Shoulders Shampoo (1% Zinc Pyrithione) with Head and Shoulders Conditioning Rinse (0.3% Zinc Pyrithione) versus Merit Shampoo with Merit Moisture Rinse

Zinc pyrithione (ZPT) has long been recognized as a therapeutic agent that is safe and effective against dandruff and seborrheic dermatitis at levels of 0.95% to 2% in shampoos and 0.1% to 0.25% in grooming aids. In a recent antidandruff efficacy clinical study conducted in a population of Japanese men and women in the cities of Kuzuha and Neyagawa japan, Head and Shoulders rinse-in-shampoo (1% ZPT) and Head and Shoulders shampoo (1% ZPT) with Head and Shoulders conditioning rinse (0.3% ZPT) were demonstrated to be significantly more efficacious at reducing dandruff flaking than Merit shampoo with Merit moisture rinse (both products contain ZPT). All Zinc pyrithione-containing products tested were significantly more efficacious at reducing dandruff flaking than the placebo shampoo. Correlating with the antidandruff efficacy ranking, subjects with severe dandruff were able to discern that Head and Shoulders rinse-in-shampoo or Head and Shoulders shampoo with Head and Shoulders conditioning rinse were significantly (p values ≤ 0.05) more efficacious at reducing dandruff flaking than Merit shampoo with Merit moisture rinse. In addition, subjects on the Head and Shoulders shampoo with Head and Shoulders conditioning rinse treatment perceived that they had significantly (p values ≤ 0.05) healthier scalp and less severe scalp dryness post-treatment than the subjects on Merit shampoo with Merit moisture rinse treatment. Head and Shoulders shampoo with Head and Shoulders conditioning rinse were rated by the subjects to be significantly Ip values ≤ 0.05) more effective in controlling dandruff flaking, scalp itch and scalp dryness than Merit shampoo with Merit moisture rinse. In this clinical study, we found that 37% of the Japanese population had dandruff significant enough to qualify for entry on study but were not using any antidandruff products. It is obvious that these subjects could benefit from using Head and Shoulders shampoo and Head and Shoulders conditioning rinse. Professional recommendations for the regular use of Head and Shoulders shampoo and Head and Shoulders conditioning rinse may be a key to the treatment and prevention of recurrent dandruff in the Japanese population.