While the dermatologists I spoke with were all proponents of growth factors, it is a controversial topic. Some derms question whether topical growth factors can be effective without delivery through microneedling or laser resurfacing, claiming their the molecules are too large to effectively penetrate the upper layer of the epidermis. There is also concern that because growth factors are mitogenic, theoretically they can cause cancer cells to replicate, but there has been no evidence to suggest that topical growth factors do.
“Growth factors are molecules, enzymes, and are particular pathways that contribute to cell proliferation or cellular growth and turnover. The reason there’s a bit of controversy is that uncontrolled cellular growth is, by definition, cancer,” explains Henry. “So there was always this concern, especially in the early iterations, that if we use these growth factors, it could simulate skin cancer. Now a lot of formulations have changed and we understand better what growth factors are in this particular serum or cream and what pathways they activate, but before that we didn’t.”
There is also the question of where the growth factor might come from. In 2018, Sandra Bullock and Cate Blanchett caught flack for talking about $650 “penis facial” they had come to the well-known esthetician Georgia Louise’s spa. The growth factors used in the serum were “derived from the stem cells of the human fibroblast taken from Korean newborn baby foreskin.” SkinMedica’s serum also uses growth factor proteins created in the laboratory, but derived from the stem cells of a single neonatal foreskin over 20 years ago. However, if you are curious about growth factors and would rather not use anything associated with human cells, choose a plant-based product.