Not changing the skin, but creating the environment in which skin can restore itself. This is why EGF, FGF, exosomes, and PDRN are drawing attention as core ingredients in regenerative skincare.
From the Age of Anti-Aging to the Age of Regeneration
For a long time, “anti-aging” was the defining theme of the cosmetics and skincare industry. This approach focused on softening and concealing the traces of aging that had already occurred. Filling wrinkles, correcting hyperpigmentation, and temporarily compensating for reduced elasticity formed the core of the industry. Recent trends differ. Dermatological science and the cosmetics industry are shifting focus, moving from covering the skin to restoring it, and further, to creating the physiological environment in which skin can regenerate on its own. The keyword that best captures this shift is regeneration.
Skin regeneration is not a matter of filling in damaged areas. It is a physiological process in which damage is recognized at the cellular level and repair signals are activated, helping tissue return to normal condition. Behind this shift is the well-aging trend. Consumer attitudes have moved toward managing aging in a healthy way, rather than hiding or resisting it, and this outlook has spread across the beauty market. Alongside it, skin health has increasingly come to be viewed as an indicator of overall wellness.
Cosmetics are becoming healthcare solutions for managing skin health, rather than purely beauty products. This shift is also reflected in growing interest in ingredients’ mechanisms of action and the scientific evidence behind them. EGF, FGF, exosomes, and PDRN stand out as the regenerative ingredients currently drawing the most attention from dermatological science and the cosmetics industry.
Skin Damage and the Regeneration Mechanism
Skin is the organ most directly exposed to the external environment. It is continuously affected by factors such as UV radiation, heat exposure, oxidative stress, microinflammation, and lifestyle habits. UV radiation induces DNA damage and generates reactive oxygen species (ROS), accelerating photoaging. Repeated heat exposure accelerates the denaturation of collagen and elastin, weakening skin structure. When chronic oxidative stress, microinflammation, sleep deprivation, and stress are added on top of this, the skin’s natural recovery capacity gradually declines.
In response, skin follows a repair sequence: damage occurs, an inflammatory response follows, growth factors activate, cells proliferate and migrate, and collagen production and tissue remodeling take place. EGF and FGF act as growth factors that drive cell proliferation and migration, while PDRN and exosomes support the regenerative environment through DNA repair and gene expression regulation. If growth factors are signals instructing cells on what action to take, PDRN and exosomes are closer to laying the groundwork that makes that action possible.
01 EGF
Epidermal Growth Factor
EGF is a low-molecular-weight polypeptide growth factor composed of 53 amino acids. American biochemist Dr. Stanley Cohen first discovered it in mouse salivary glands in 1962, and he received the 1986 Nobel Prize in Physiology or Medicine for establishing the concept of growth factors. Among regenerative ingredients, EGF is considered to have the longest history of research and the most accumulated scientific evidence.
EGF’s primary site of action is the epidermis. The epidermis, the outermost layer of skin, performs barrier function through direct contact with the external environment while undergoing continuous cell turnover as a dynamic tissue. EGF initiates its action by binding to the EGF receptor (EGFR) on the cell membrane of keratinocytes, the keratin-forming cells located in the basal layer of the epidermis. When EGF binds to EGFR, tyrosine kinase within the receptor is activated. This triggers a sequence of phosphorylation reactions that transmit signals into the cell, sequentially activating the Ras-MAPK and PI3K-Akt pathways.
As the end result of this signaling cascade, keratinocyte division and proliferation are promoted, and migration, the movement of cells toward damaged areas of the epidermis, becomes more active as well. Through this process, EGF activates skin turnover and supports the recovery of damaged epidermis. It also contributes to skin barrier maintenance by stabilizing stratum corneum structure, and supports improved skin texture as normal turnover proceeds.
02 FGF
Fibroblast Growth Factor
FGF is a polypeptide growth factor like EGF, but its primary site of action is the dermis rather than the epidermis. The dermis, where structural proteins such as collagen and elastin are distributed, is responsible for skin elasticity and support. FGF initiates its action by binding to the FGF receptor (FGFR) on dermal fibroblasts.
This triggers activation of tyrosine kinase and the Ras-MAPK and PI3K-Akt signaling pathways, promoting fibroblast proliferation and metabolism. Activated fibroblasts increase synthesis of type I and type III collagen, elastin, and extracellular matrix (ECM) components. This raises the density and strength of the dermal matrix and supports the maintenance of skin elasticity. This process forms the basis for improving structural signs of aging, such as sagging and wrinkles. While EGF activates epidermal keratinocytes to support turnover and skin texture, FGF activates dermal fibroblasts to promote collagen and elastin synthesis and maintain the skin’s structural elasticity.
03 Exosomes
Exosomes are extracellular vesicles measuring 30 to 150 nanometers, secreted by various cells including stem cells. Within their double lipid membrane structure, similar to a cell membrane, exosomes carry proteins and lipids as well as genetic material such as mRNA and microRNA. Importantly, exosomes are not stem cells themselves, but messengers carrying information sent by stem cells. Exosomes fuse with target cells or are absorbed into them, directly delivering their mRNA and microRNA content.
Unlike growth factors, which transmit signals through membrane receptors, exosomes deliver genetic information directly into cells, regulating gene expression itself. In particular, microRNA carried by exosomes has been shown to suppress expression of inflammatory cytokines such as TNF-α and IL-6, while promoting expression of genes required for collagen and elastin synthesis. As a result, exosomes may ease excessive inflammation while guiding remodeling of the damaged dermal matrix, contributing to an environment that supports skin regeneration. Exosomes can be understood as an information-delivery platform that addresses regeneration and inflammation regulation simultaneously, at the level of gene expression.
04 PDRN
Polydeoxyribonucleotide
PDRN is a low-molecular-weight DNA fragment extracted from salmon testes. It was first used in medicine for wound healing before its application expanded into skin regeneration. PDRN acts through two main mechanisms. The first is an anti-inflammatory effect mediated through the adenosine A2A receptor. When PDRN binds to the A2A receptor, expression of inflammatory cytokines such as TNF-α and IL-6 decreases, while secretion of the anti-inflammatory cytokine IL-10 increases, helping regulate the inflammatory response at the site of damage.
The second mechanism is DNA regeneration through the salvage pathway, a metabolic pathway in which cells recycle materials rather than discarding them. Cells typically expend considerable energy synthesizing new DNA, but PDRN serves as material for the salvage pathway, allowing externally supplied DNA fragments to be recycled. This allows cells to synthesize DNA more quickly using less energy, supporting more efficient repair and regeneration of damaged tissue.
Both exosomes and PDRN act at the level of genetic material, but their roles differ. If exosomes are “messengers” that regulate gene expression through mRNA and microRNA, PDRN is closer to a role that supplies the raw material needed for DNA synthesis, laying the groundwork for cellular repair.
Limitations of Regenerative Ingredients
EGF, FGF, exosomes, and PDRN each differ in mechanism of action and biological characteristics, but they share a common limitation when applied in cosmetics: passing through the skin barrier, particularly the stratum corneum. The stratum corneum, a structure in which dead corneocytes and lipid components such as ceramide are tightly arranged like bricks and mortar, functions to block the penetration of external substances.
EGF and FGF are large-molecular-weight polypeptides, while exosomes are nanoscale vesicles enclosed by a lipid bilayer. PDRN, too, consists of highly hydrophilic DNA fragments. All of these ingredients have either high molecular weight or high hydrophilicity, making it difficult for them to pass through the stratum corneum. No matter how strong an ingredient’s biological activity may be, it is difficult to fully realize its expected efficacy if it cannot effectively pass through the skin barrier. For this reason, delivery technology is regarded as a core competitive factor in regenerative cosmetics.
A Total Solution to Enhance the Synergy of Regenerative Ingredients
One representative delivery technology is the liposome, a microcapsule that encloses active ingredients within a phospholipid bilayer similar to human cell membranes. Because of its high structural affinity with cell membranes, it can penetrate relatively smoothly through the lipid pathways between corneocytes, while also protecting its contents from oxidation and degradation.
Encapsulation technology is also widely used. Beyond liposomes, active ingredients may be enclosed in various forms, including nanoemulsions and polymer-based microcapsules, to secure both stability and penetration at the same time.
Microneedling (MTS) creates microscopic channels in the stratum corneum, helping active ingredients reach deeper into the skin. The microchannels formed through microneedle patches or procedures are considered an effective delivery technology because they provide a physical delivery route regardless of an ingredient’s molecular weight or polarity.
Spicule peeling is a delivery technology that uses microscopic needle-like structures derived from marine sponges to form physical microchannels in the stratum corneum. It works on a principle similar to microneedling, and has recently drawn active research interest for its use of a naturally derived material.
These four ingredients operate at different levels: the epidermis, the dermis, DNA, and gene signaling. No single ingredient alone can complete the full picture of regeneration. The potential of all four will emerge only when delivery technology and ingredient combinations align effectively.
Editor GAHEE, BAEK
Image Shutterstock
The Signature Magazine – August 2026 Issue