Stocksy If you told me in years prior that salmon sperm (yes, you read that correctly) and skincare would be used in the same sentence, I'd have my concerns. But alas, here we are—salmon sperm is a trending ingredient, one that made Google's Year in Search at that. There's a lot to unpack here, but let's start extremely simple. This buzzy ingredient often appears on labels as "PDRN," short for polydeoxyribonucleotide (say that five times fast).