Growth factors are proteins that play a critical role in cellular signaling, proliferation, and differentiation, including within the hair follicle. Their use to support the hair/body system, particularly for promoting hair growth and preventing hair loss, is based on scientific research, especially in the context of dermatology and trichology. Studies have shown that certain growth factors, such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF-1), and fibroblast growth factors (FGFs), are important for the anagen (growth) phase of the hair cycle. These factors can stimulate the proliferation of dermal papilla cells and promote angiogenesis, both of which are essential for healthy hair growth.

Clinical evidence includes the use of platelet-rich plasma (PRP) therapy, which delivers a concentration of autologous growth factors to the scalp and has shown efficacy in some studies for androgenetic alopecia and other forms of hair loss. Additionally, topical formulations containing recombinant growth factors have been explored, with variable results in promoting hair density and thickness. However, most of the high-quality evidence is limited to small-scale studies and pilot trials, and there is a need for larger, well-controlled clinical trials to fully establish efficacy and long-term safety.

In summary, while there is a scientific basis for the use of growth factors in supporting hair growth, the evidence is moderate and still evolving, justifying a rating of 3 out of 5.