The present disclosure provides a high pressure discharge lamp for collagen regeneration in the skin comprising an arc tube (101) equipped with tungsten electrodes (102) characterised in that the arc tube is filled with a chemical mix comprising halides of sodium, lithium or any combination thereof, and the electrical loading is in the range 30 to 90 W/cm2 of arc tube surface area, so as to optimise the spectrum for realising the maximum generation efficiency of collagen active radiation.
