['Artificial reduction of abnormal transepidermal water loss (TEWL) is considered to improve skin diseases associated with a defective barrier function. Treatment of the skin with moisturizers is also known to influence skin barrier function. Whether or not differences in occlusion between creams contribute to their effects on the skin barrier function is unknown.', 'To investigate the long-term effects of a semipermeable membrane on the skin barrier function in normal skin. In addition, the occlusive properties of two creams were studied.', 'The study was randomized, controlled and evaluator-blind using measurement of TEWL and skin susceptibility to sodium lauryl sulphate as indicators of skin barrier function.', 'Coating of the skin with a silicone membrane for 23 h per day for 3 weeks improved skin barrier function, whereas no significant changes were found after using the membrane for 8 h per day.'] Does artificial reduction in transepidermal water loss improve skin barrier function?