Pearl Extract comes from, well, pearls
However, for high-throughput laboratories, the time savings from eliminated reconstitution steps and the ability to use reagent across multiple days may offset the per-assay cost difference
Findings in this area point to improved collagen density and tissue repair markers in research models, though this remains a smaller and more emerging body of literature compared to the muscle and metabolic research described above, and study authors generally note the need for further controlled data before drawing firm conclusions
As the publication concluded, Supplementation with a combination of vitamin D and L-cysteine or glutathione precursor, rather than supplementation with vitamin D alone, is beneficial and helps achieve more successful vitamin D supplementation. How Supplementing with L-cysteine can Improve Vitamin D Status and Activity Glutathione is made of 3 different amino acids: cysteine, glycine, and glutamic acid