In the present work a practical claim substantiation study is shown by the example of 5 commercially available body lotions. Their efficacy with respect to effects on transepidermal water loss (TEWL) and stratum corneum (SC) hydration of ageing skin has been examined. Results were obtained after single and repeated application (14 days, 2 x a day). The best performing product was then selected and further tested for its potential effects on sodium lauryl sulfate (SLS)-damaged skin. This was done in a younger population and the recovery of the impaired barrier function was followed by TEWL measurements. The selected body lotion had a high efficacy, improving both the TEWL and SC hydration of ageing skin by more than 30%. When applied to SLS-damaged skin, the product was able to improve skin barrier repair in comparison with physiological barrier repair. The results of this study show that a combination of non-invasive objective measurements can be used to substantiate product claims. Claims can be made with respect to protective and preventive properties of products, but also as to effectiveness of topical skin treatment in the case of abnormal barrier function or barrier restoration.