The Ordinary GF 15% Solution Versus Kate Somerville Kateceuticals Supercell Rejuvenation Serum

In a formula, EGF acts like a messenger that tells skin cells to get busy: it encourages keratinocytes to divide/migrate, supports fibroblasts, and is best known for its role in wound healing.

EGF plays a pivotal role in wound healing and tissue maintenance by regulating cell survival, proliferation, migration, and differentiation; a lab-made recombinant human EGF has long been used to promote skin wound healing.

The current evidence is promising but modest at scale.

In one 3-month study of 29 women with photoaged skin, a topical EGF serum significantly improved brown pigmentation, skin texture, pore size, and wrinkles. A systematic review noted that recombinant EGF promotes migration of aged fibroblasts and increases hyaluronic acid + collagen synthesis.

The honest caveat is that EGF is a large, water-loving molecule so how well it penetrates intact skin is still debated and a lot of the strongest claims come from small or brand-run studies.

Typical use levels are very low and expressed in parts per million rather than percentages. Most cosmetic products land somewhere under 10 ppm (roughly 0.0001-0.001%).

Rather than being brewed in bacteria, it's grown inside Nicotiana benthamiana, a tobacco relative used as a tiny plant "factory" (a technique called molecular farming that's well documented in the scientific literature for producing functional human growth factors).

In a formula, this ingredient acts as an anti-aging and skin conditioning active.

TGF-β2 is a signaling molecule that switches on the pathway in your skin to stimulate the synthesis of collagen I and support the skin's own lipid production.

This is why manufacturer's pitch it as a retinol-like alternative. And unlike retinoids, this ingredient doesn't increase your skin's sensitivity to the sun in the first few weeks of use. This makes it suitable for daytime use.

The headline claims for this ingredient come from the manufacturer's own 28 day in vivo studies. They reported reductions in wrinkle count, volume and depth, pore size reduction, and increases in radiance, hydration, firmness, and elasticity.

Though these sound solid, just keep in mind these are company-run trials rather than independent peer-reviewed dermatology papers.

The broader peer-reviewed work mostly backs the production method and the general collagen-stimulating biology of plant made TGF-β2 proteins and not an exact finished product.

One honest caveat: the molecule is large (like collagen) so it likely sits more at the surface rather than penetrating deeply into skin.

Typical concentration use levels are quite low and the actual bioactive protein is only present in trace amounts since growth factors work at very low doses.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

It is non-ionic and forms a triple helix in solution. This is just a fancy way of saying it builds a smooth, cushiony, and non-sticky gel that feels silkier than many other gums.

Another perk of this ingredient is that it is very sturdy and holds up across a wide pH range (~2-11). It's also good at resisting heat and hydrolysis.

Since it holds water at the skin surface, it can provide some light hydration as well.

Typical use levels are around 0.25-2%; formulators usually use 0.2-0.5% to thicken lotions and up to 2% for a firmer gel base.

This ingredient has been found safe in cosmetics with no meaningful evidence of skin sensitization.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

An in-vivo study done by the manufacturer claims:

While this seems promising, more studies are needed. (Though there's no harm in testing out this ingredient!)