Growth factors are seen as the holy grail in skin care. They are the closest thing we have to the long-sought but still elusive miracle cream for skin ageing. In dermatology circles, growth factors have created both excitement and controversy. Growth factors are in hot demand in skin care products for their potential ability to exfoliate the skin, reduce fine lines and wrinkles, and improve skin firmness.
Even the Journal in Drugs and Dermatology has recognised the important role of growth factors and cytokines in repairing ongoing cellular damage in our skin and put them at the top of its Skin Health and Beauty Pyramid.
Growth factors are considered to be as close to a drug as you can get, given they effectively communicate with receptors in our skin and deliver transformative changes. These signal molecules communicate with cells, sending messages to repair, rebuild or proliferate. There are hundreds of different growth factors and they control more than 300 cell types in the human body, but once we become adults our natural production of these diminishes and this becomes evident in the ageing of our bodies, including our skin.
Human Growth Factors, more specifically, are growth factors that have been derived from human stem cells and this is why they have come under medical regulatory scrutiny.
After the age of 20, our skin’s thickness diminishes by 1% a year, and for women becomes about 30% thinner some five years after menopause.
Independent studies have shown they can enhance wound healing, reduce wrinkles and smooth skin. A 2007 study in the Journal of Drugs in Dermatology found an average 83% reduction in wrinkles around the eye and 50% reduction in wrinkles around the mouth of people using a human growth factor cream for 60 days.
Growth factors are naturally found in the skin, however they diminish with age both in terms of production and preservation. Like peptides, there are different types of growth factors and they each play a specific role, for example generating new blood vessels, stimulating collagen expression or encouraging the growth of epidermal cells.
However, if ever there was a highly contentious area in the world of skin care, Human Growth Factors would be it. There are numerous skin care products on the market containing growth factors, all promising skin rejuvenation.
These stem cells can be derived from different human cells:
However, interestingly, fat stem cells are more likely to produce growth factors that help the functioning of fat cells while bone marrow stem cells are more likely to produce growth factors that improve the functioning of the bone marrow. When it comes to the skin, ideal growth factors are those produced by fibroblasts. And getting these fibroblasts to behave like those
A study in 2017 found that growth factors derived from human stem cells outperformed those derived from non-human stem cells.
They are claimed to work by:
Best known is SkinMedica’s TNS Essential Serum, which contains ‘human conditioned media’ as its principal ingredient: a mix of growth factors cultured from grown and conditioned human stem cells that originally came from baby foreskins. SkinMedica says that Human Growth Factors show much faster results when combined with strong antioxidants and peptides, and that the growth factors need to be in a stabilised form. Interestingly, it also recommends the inclusion of a Vitamin A (Retinol) product in your skin care routine for more serious skin concerns, saying it works in a slightly different way to growth factors.
SkinMedica withdrew its distribution of products in Australia in 2018, although its products, including the TNS skin care range, are still available in other parts of the world.
There is controversy around the source of the Human Growth Factors used in skin care products and some ongoing concern about the potential for fibroblasts, when activated, to contribute to the growth of existing melanoma cells.
In Australia, the Joint Advisory Committee on Chemicals and Medicines Scheduling considered the use of a plant-derived Epidermal Growth Factor in the use of cosmetic products and in 2017 determined the factor could be used in cosmetic products at a level of 0.0001% or less for anti-ageing. In its decision, the Committee cited a low level of risk at these concentrations and international standards. At such low levels, it would doubtful it would be delivering any benefits, in any case.
Despite this regulatory restriction, we still see products in the market and now references are being made to “cell communicators” rather than Epidermal Growth Factor.
Research on the effectiveness of plant stem cells is in its infancy. They may have antioxidant and anti-inflammatory effects. Molly Campa and Elma Baron, in Cosmetics, 2018, state that plant stem cells are dead cells and so cannot communicate with human skin stem cells, but their secondary metabolites may have some anti-ageing benefits for skin. Other experts have less politely described plant stem cells as nothing more than chopped up plant bits.
Interestingly scientists from Mibelle Biochemistry conducted a human study using a 2% Uttwiler Spätlauber extract in a lecithin liposomal deliver system (PhytoCellTec Malus Domestica) and found it reduced wrinkle depth in the crows’ feet area of 20 participants. Wrinkle depth was reduced by an average of 8% after two weeks and by 15% after four weeks when applied to the area twice a day. It is worth being aware that these scientists were behind the development of PhytoCellTec.
In short, claims that rare ingredients derived from mountain apples, prickly pear or barley can preserve your skin and reverse ageing make for great marketing, however they are not clearly proven, given the lack of peer-reviewed published studies on plant growth factors.