A Penn State study showed Vicks VapoRub to be more effective than placebo petroleum rub for helping cough and congestion with regards to helping children and adults sleep. However, the study also showed that, unlike with the petroleum rub placebo, Vicks VapoRub was associated with burning sensations to the skin (28%), nose (14%) and eyes (16%), with 5% of study participants reporting redness and rash when using the product. The study's first author is a paid consultant for Procter & Gamble, maker of VapoRub.