Provided is a process of and product resulting from adding a sub-lethal amount of a peroxide, or said peroxide in combination with sub-lethal ultra violet radiation, to a growing culture of a yeast； observing the change in absorbance of the culture at 256 nm as a measure of the injury occurring to the yeast cells, and upon reaching a predetermined absorbance value, purifying the water-soluble yeast extract from the peroxide containing yeast culture. The resulting product has at least 1.5 respiratory units per mg dry weight and has significantly increased amounts of 15, 25 and 55 kilo Daltons (kD) molecular weight products compared to a Live Yeast Cell Derivative as determined by SDS slab gel electrophoresis. This product can be combined with a cosmetically acceptable carrier to provide a composition suitable for topical application to the skin.
