Growth factors in skincare are used to help give the skin a continuously young look and they have become extremely controversial, being blamed for causing cancer. On the other hand growth factors have also been considered ineffective due to their high molecular weight proteins not being able to get past the stratum corneum.[1]
What are growth factors?
Growth factors are found in abundance throughout the body, they are large proteins that float between cells communicating crucial messages relevant to growth, healing, and survival. They regulate cellular growth, proliferation and differentiation under controlled conditions. They play an essential part in maintaining healthy skin structure and function.[3] Growth factors are secreted by all cell types in the epidermis and dermis including keratinocytes, fibroblasts and melanocytes. When these growth factors bind to receptors on cell surfaces, they can send commands to replicate, repair, and rejuvenate.[4]
In physiological situations, skin stem cells produce growth factors whose primary role is to repair damaged skin by regenerating new skin cells. Growth factors promote the formation of collagen and elastin to provide firmness and elasticity. As we grow older the body start producing fewer growth factors.[5]
What role do growth factors play in skincare?
One approach to keep skin young is to regularly use skin care products with a high concentration of stable growth factors. Daily use of these factors is known to help reduce the appearance of fine lines, wrinkles and improve skin tone and texture.[3] Growth factors stimulate biochemical pathways that regulate cellular growth, proliferation and differentiation under controlled conditions, which play an important part in maintaining healthy skin structure and function.]6]
By our late 20s, the skin starts producing smaller quantities of growth factors which results in less cell growth, thinner and less elastic skin, decrease collagen production and elastic fibres begin to stiffen, which will lead to wrinkles and sagging. Furthermore, sun exposure and pollution, accelerate the process. But growth factors, when applied regularly for several weeks, can act as a sort of replacement therapy, restoring part of the normal signals that support healthy skin when we’re young. This ability for resuscitating basic skin functions, like cell turnover and collagen construction, makes growth factors a logical fit in product formulas aiming for lineless, even-toned, luminous effects.[4]
Where do growth factors come from?
The growth factors found in serums, gels, and creams were initially extracted from human cells, but due to the complexity, the cost and the advance in biotechnology, nowadays, there are many ways to obtain growth factors. They can be derived from several different human cells grown in a laboratory, extracted from one’s blood (PRP - platelet rich plasma), or bioengineered from non-human sources such as snails and some plants.[3]
Concerns about the use of growth factor on skincare:
Growth factors for use in skincare are highly controversial due to a number of reasons, some of the current concerns are:
In skincare products, they would be used repeatedly, and possibly over long periods;
If they cause cells to over-proliferate, they might cause cancer, this worry comes from the fact that some malignant cells in our body have receptors for certain growth factors;[7]
In the case of TGF, which stimulates collagen production, it can encourage scarring, since scars are the result of excessive collagen production;
It is not known whether growth factors contained in cosmeceuticals are stable or can be absorbed adequately;[3]
Controversy surrounding growth factors for use in skincare
Growth factors are one of the most controversial cosmetic ingredients in terms of safety. With all of the givens and the unknowns, it is logical that there would be controversy around growth factors, from where they are derived to the potential for efficacy and need for technology to help them cross the stratum corneum.
Some experts and doctors think that growth factors in skincare products are good for marketing, and totally worthless when it comes to actual results, since growth factors are proteins and topically applied proteins cannot penetrate through intact stratum corneum to the living epidermis and thus cannot stimulate growth or the production of anything. But they do agree that when used together with micro-needling, resurfacing, fractional resurfacing or injection, growth factor are effective.[6]
While other doctors consider them an essential part of a daily skincare routine. They state that the problem with growth factor products in general is that the percentage of growth factor can be very low so that the skin does not show any overall improvement. Leading to the belief that the effectiveness of a product containing growth factors is tied to their concentration.[6]
Recently, a suit was brought stating that the growth factors were responsible for the induction of skin cancers because growth factors could promote growth of both normal and cancerous skin. Showing that the growth factor cream was challenging, and the suit did not progress. Still, this lawsuit highlighted an important question, whether or not growth factors are safe?
Alternatives to growth factors
With the previous concerns in mind, three alternatives to growth factors have been suggested:
1. Heparan sulphate
2. Tripeptide palmitoyl
3. Defensin (a small molecule)
Heparan sulphate is a component of the extracellular matrix. This glycosaminoglycan is covalently attached to core proteins to form proteoglycans. Heparan sulphate is much smaller than growth factors and plays a role in skin healing. Studies have shown that when a cream containing heparin sulphate was applied to skin for eight weeks, there was improvement in hydration, firmness and elasticity. Tripeptide Palmitoyl improves collagen and elastin production and promotes healing. Defensins are microbiocidal peptides that activate new stem cells. When applied to skin, defensins improve pores, deep wrinkles and superficial wrinkles.[1]
Conclusion
There is a gap in the scientific knowledge and lack of well controlled clinical studies. Most of the research on human growth factors for skin has mostly been focused on wound healing, and at short-term use. Much is still unknown, especially in regard to long-term risk or stability, when growth factors are used in cosmetics and applied to the skin.
Bibliography
1. Hot Topics In Skin Care. HAPPI https://www.happi.com/contents/view_online-exclusives/2018-03-08/hot-topics-in-skin-care/.
2. Growth Factors: Your Essential Guide. FutureDerm https://www.futurederm.com/growth-factors/ (2016).
3. Mehta, R. C. & Fitzpatrick, R. E. Endogenous growth factors as cosmeceuticals: Growth factors as cosmeceuticals. Dermatol. Ther. 20, 350–359 (2007).
4. Edgar, J. The Truth About Growth Factors in Skin Care and Why They’re Controversial. Allure https://www.allure.com/story/growth-factors-in-skin-care-penis-facial.
5. All You Need To Know About Growth Factors - Why Your Skin Needs Growth Factors. Skin Beauty https://www.skin-beauty.com/blog/all-you-need-to-know-about-growth-factors-why-your-skin-needs-growth-factors/.
6. Growth Factors: Are They Good for Patients? | Cosmetic Surgery Forum – Practical. Honest. Insightful. https://www.cosmeticsurgeryforum.com/growth-factors-patients/.
7. Growth Factors in Topical Skin Care | Prime Women Media. https://primewomen.com/beauty-and-fashion/skin-care-and-makeup/growth-factors-topical-skin-care/.