This 2016 review investigates evidence for the commercial use of silicon supplements. On the skin, it is suggested that silicon is important for optimal collagen synthesis and activation of hydroxylating enzymes, improving skin strength and elasticity. Regarding hair benefits, it was suggested that a higher silicon content in the hair results in a lower rate of hair loss and increased brightness. For these beneficial effects, there is growing interest in scientific studies evaluating the efficacy and safety of using dietary supplements containing silicon.
References:
Araújo, L. A., Addor, F., & Campos, P. M. (2016). Use of silicon for skin and hair care: an approach of chemical forms available and efficacy. Anais brasileiros de dermatologia, 91(3), 331–335. https://doi.org/10.1590/abd1806-4841.20163986