Female scientist looks at human growth factors through microscope

Five or so years ago, I tried to wrap my head around human conditioned media, an anti-aging ingredient derived from the human body itself. Although we were on the brink of a tremendous beauty breakthrough, it was complex and controversial. Back then, there were only a few serums with human stem cells and the most interesting — and effective — were a byproduct of academic research into wound healing.

Now, there are many more in a landscape and with a nomenclature that has become increasingly confusing — take your pick from growth factors, stem cells, conditioned media and peptides. They are not interchangeable and so it is worth getting to know how they work and how they differ.

This article focuses on human proteins, not plant stem cells. There are many different proteins and, although they all send signals to cells, their roles differ. Mostly, these proteins are repairers and much of the research on them has been on wounds. Extracts of stem cells contain peptides, amino acids, and enzymes.

Stem cells

The progenitor cells of the human fibroblast can be taken from newborn baby foreskins or human fat (adipose) cells. Embryonic stem cells are not used in cosmetics. From the progenitor cell, many thousands of new cells will be grown in the lab. Understanding this may help dispel myths (and fears) that new human cells are extracted for each batch of cosmetics and that they may be diseased or cancerous. The progenitor cell is supposedly pristine and is cloned in a laboratory.

Note that some manufacturers claim that adult stem cells are not as potent as those taken from young humans. Lifeline Stem Cell Skincare, a brand that I recently discovered, uses stem cells from unfertilized eggs. These stem cells have signaling proteins and amino acids, and Lifeline says they are more powerful than adult stem cells and the “human conditioned media.”

Human conditioned media

Conditioned media (sometimes called human fibroblast conditioned media) is, in fact, the solution (sugars, amino acids and such) that is put in the petri dish in which skin cells are grown. Examples of anti-aging brands that use human conditioned media are ReLuma and AQ Skin Solutions. Both claim to use complexes that contain many different growth factors.

Epidermal growth factors

Epidermal growth factors are made up of 53 amino acids and they stimulate cell growth, differentiation and proliferation. Research has shown that isolated EPGs can stimulate wound healing and skin regeneration. There are many different EPGs and they do different things. TGF-b, for example, stimulates collagen production, promotes the synthesis of extracellular matrix proteins and inhibits matrix degradation (or the thinning of your skin).

Pet owners will love this factoid: Dr. Mike Longaker in the Department of Surgery at Stanford points out that animals lick their wounds because their saliva includes a high concentration of EGF. There are numerous clinical trials demonstrating that EGF accelerates wound healing, such as this 2006 study on rats. What is less clear, however, is the mechanism.

For example, I spent some time looking at the impact of EGF on collagen production and found the research to be contradictory. There is research that concludes that EGF has a positive effect: EGF “stimulates fibroblasts to secrete collagenase” and “continuous topical application of epidermal growth factor [EGF] to granulation tissue increases the rate of collagen accumulation.”

E’shee has chosen to focus its skincare range on the FGF-1 family of growth factors involved in angiogenesis and wound healing. 


Recently, specific growth factors have been isolated and the most common are oligopeptides. These are proteins with up to 10 amino acids and have become a popular ingredient in skin care. Usually these are synthetic — that is to say, manufactured in a lab to mimic the signaling qualities of human proteins. It is usually listed as Sh-Oligopeptide-1. This is the key ingredient in Stemulation Hi-Impact. Or you will see it with the pre-fix Rh (recombinant); this version is in GloTherapeutics Super Serum.