Production and Certification of Transfer Factors in America
First Patent Transfer Factors USA
Product quality is the main achievement of the 4LIFE RESEARCH manufacturershttps://www.youtube.com/watch?v=iunHRAo8DXc&t=155s

Physicaians desk reference USA:https://www.4life.com/corp/video
http://transferfactor.hu/wp-content/uploads/2019/02/Pro-TF-free-of-adulteration-certificate.pdf