Heading to South Korea for cosmetic tourism has been a hot topic of conversation over the last few years, given the country’s reputation for using innovative ingredients and techniques that are usually not readily available in the United States. The most popular of late has been polydeoxyribonucleotide or PDRN. Derived from salmon or trout sperm, it’s become a hot ingredient stateside, where it’s a key component of serums, lotions, and sheet masks. While here it’s only approved for topical use, in Asia it’s among a group of treatments called skin boosters that are injected into the dermal layer to help with texture, collagen production, and overall radiance. The latest addition to this class of cosmetic enhancers that’s become a favorite in big cities like Seoul is Re20. The kicker? It’s made from donated cadaver cells.  Related Articles Re20 is by Elravie, a Korean company known for its fillers and other cosmeceutical skincare products.…