https://www.smore.com/mc4hj-kratom-maeng-da-review-guide 

Kratom Maeng Da that they had found an individual gene that could make clear why injuries thatspell mere discomfort for just one person could be mean agony for another. Thisgene, which controls the mu opiate receptor (a molecule that assists the body'sall natural opiates enter cells), also provides clues as to why some  personsget more relief than other from opium-based painkillers.