Human-Comparable vs. Human-Derived Growth Factors: Why the Distinction

What "human-derived" actually means

Human-derived growth factors are sourced from cultured human cells. In practice, human cells are grown in a laboratory environment, stimulated to produce growth factors, then harvested and purified for use in cosmetic formulations.

The process produces biologically active proteins. But it also introduces variables that are difficult to eliminate entirely: batch-to-batch inconsistency inherent to biological cell culture, the complexity of purification at commercial scale, and reliance on a human donor supply chain. The purity of the final product depends on the precision of each step in that chain.

What "human-comparable" means — and why it is not a compromise

Human-comparable growth factors are synthesized. Rather than extracting them from cultured cells, they are bioengineered to be bio-mimetic: structurally identical to the growth factors the human body produces, but created through a controlled synthetic process with no dependence on human donors.

"We refer to human-comparable rather than human-derived as this explains the origin of the growth factors we are employing in our product. Human-comparable growth factors are synthesized to be bio-mimetic or bio-identical. This matters due to the high level of purity and reproducibility rate at which human-comparable growth factors can be generated. This process is also highly sustainable and has zero dependence on human donors."

Raffi Balian (SVP Global R&D/PD/Regulatory & QA at ZO Skin Health, Inc.)

The synthesis approach is also fully sustainable. No donor tissue, no cell culture variability, no dependence on biological supply chains at any stage of production.

The practical advantage: concentration control

Purity and reproducibility are meaningful on their own. But the deeper advantage of the human-comparable approach is what it enables on the formulation side: precise control over which growth factors are present and at what concentration.

"With human-comparable growth factors, we can control the concentrations of the target growth factors, meaning that we are providing a targeted solution."

Raffi Balian (SVP Global R&D/PD/Regulatory & QA at ZO Skin Health, Inc.)

That distinction is significant. A growth factor complex derived from cell culture delivers a mixture of proteins, the composition of which can vary across batches. A synthesized human-comparable formula delivers exactly what the formulator specifies: defined growth factors at defined concentrations, every time.

The five growth factors in ZO’s formula — and why each was chosen

ZO’s Growth Factor Serum uses five human-comparable growth factors, each selected for a specific biological function:

• IGF-1 (Insulin-like Growth Factor-1): Supports collagen and elastin production; promotes cell renewal
• EGF (Epidermal Growth Factor): Signals cellular regeneration and helps maintain skin barrier integrity
• Acidic FGF (Fibroblast Growth Factor): Supports tissue repair and dermal cell function
• Basic FGF: Promotes fibroblast activity; aids in structural protein synthesis
• VEGF (Vascular Endothelial Growth Factor): Supports microvascular health and nutrient delivery to skin cells

"These growth factors collectively enhance skin health, support collagen and elastin bundles, enhance skin elasticity and plumpness, leading to an improved skin appearance."

Raffi Balian (SVP Global R&D/PD/Regulatory & QA at ZO Skin Health, Inc.)

Human-derived vs. human-comparable: a formulation comparison

What this means for clinical outcomes

Concentration control has a direct consequence for clinical validation: The product tested in a clinical study is the same product a consumer applies daily. Variables are controlled. Results are reproducible. The outcomes can be attributed to the formula with confidence.

ZO’s independent 12-week clinical study of 46 subjects reflects that precision. The 16% measured improvement in the appearance of skin elasticity and 98% subject agreement on improved skin thickness are outcomes from a formula with known concentrations, tested stability, and documented performance at each stage.

When a growth factor product cannot specify its concentration or cannot guarantee batch consistency, the link between the clinical data and the consumer experience becomes harder to establish.

Origin is not a footnote

For a product category where labels often obscure more than they explain, the distinction between human-derived and human-comparable is material. It determines what is in the formula. At what levels. And with what reliability.

If you are assessing growth factor serums, the question to ask is not just whether it contains growth factors, but which ones, at what concentration, and from what source. A ZO Skin Health provider can help you evaluate what your skin specifically needs and whether the 2026 Growth Factor Serum belongs in your protocol.