I would suggest you use the 2.5% concentration (no higher), you may still experience about 2-3 days of red skin but this quickly subsides, long term use requires use of a moisteriser. Generally the Panoxyl aquagel (check this is the product you have) is better tolerated long term becuase it is water based rather than alcohol based - for sensitive skin always avoid products that are alcohol based, hope this helps you, best wishes
