How to formulate with growth factors in skincare products.
Treat growth factors as sensitive biological ingredients. Control pH between 5.5 and 7.0, add in the cool-down phase below 35 degrees Celsius, use mild preservation, choose airless packaging, and validate stability with both accelerated and real-time tests. The same molecule can perform well or poorly depending entirely on how the finished product is built around it.
This is a practical checklist for cosmetic R&D teams and CDMOs formulating with recombinant growth factors. It focuses on the decisions that determine whether the active still works at the end of shelf life, not just at the moment of compounding.
Formulator checklist #
| Parameter | Recommendation | Why it matters |
|---|---|---|
| pH | 5.5 to 7.0 | Protein denaturation accelerates outside this range |
| Temperature at addition | Below 35 degrees Celsius | Most growth factors denature above 40 to 45 degrees Celsius |
| Phase of addition | Cool-down, post-emulsification | Minimizes heat exposure |
| Mixing | Low shear, gentle | High shear creates interfacial denaturation |
| Preservation | Mild systems with antioxidant support | Strong oxidizers degrade proteins |
| Surfactants | Avoid aggressive anionic surfactants | They denature proteins at interfaces |
| Antioxidants | Include vitamin E or equivalent | Protects sensitive residues from oxidation |
| Packaging | Airless, opaque, low headspace | Limits oxygen, light, and microbial ingress |
| Dosage | Per supplier spec (often 0.5 to 2 percent) | Both under- and over-dosing reduce ROI |
| Stability testing | 3 months accelerated, 12 months real-time, functional readout | Detects loss of biological activity |
When should growth factors be added during manufacturing? #
In the cool-down phase. The main emulsion should be fully cooled below 35 degrees Celsius before the growth factor ingredient enters the batch. Use a clean, low-shear inline addition or a slow stir under nitrogen if oxygen exposure is a concern.
How should preservation be designed? #
Strong oxidizing preservatives and certain phenolic systems can react with growth factors over time. Prefer mild, food-grade-style preservation systems supplemented with antioxidants such as vitamin E. Run compatibility tests at full preservative dose before scale-up.
Why packaging is part of the formulation #
Packaging dictates oxygen exposure, light exposure, and microbial entry over months of consumer use. For premium growth factor serums, the practical hierarchy is:
- Single-dose ampoules: best for stability and dose precision
- Airless pumps with opaque body: standard for premium serums
- Opaque tubes with one-way valve: acceptable for thicker creams
- Open jars: not recommended for sensitive proteins
What stability testing should you run? #
- Accelerated stability at 40 degrees Celsius for 3 months (predicts ~12 to 18 months ambient)
- Real-time stability at 25 degrees Celsius for 12 months
- Freeze and thaw cycles to assess emergency conditions
- Functional assays where available, not only chemical quantification
- Preservative efficacy testing per ISO 11930
Best for / Not ideal for #
- Premium leave-on serums and creams
- Recovery and post-procedure formulas
- Eye creams with airless dosing
- Scalp serums with appropriate viscosity
- Highly acidic exfoliating products
- Hot-process cleansers and shampoos
- Open jars with heavy occlusive bases
- Products that cannot support stability testing
What skincare brands should look for from a supplier #
- Validated formulation guidelines, not generic claims
- Documented pH, temperature, and preservative compatibility
- Sample protocols for accelerated and real-time stability
- Technical support during pilot batches and scale-up
- Clinical or ex vivo evidence on a representative finished product
Frequently asked questions #
How should you formulate with growth factors in skincare?
Treat them as sensitive biological ingredients: pH 5.5 to 7.0, cool-down addition below 35 degrees Celsius, mild preservation, airless packaging, and validated stability testing.
At what point in manufacturing should growth factors be added?
In the cool-down phase, below 35 degrees Celsius, with slow gentle mixing.
What dosage of growth factor should I use in a serum?
Typically 0.5 to 2 percent of a standardized supplier ingredient. Confirm against the supplier specification.
What packaging works best for growth factor formulas?
Airless pumps, opaque tubes, single-dose ampoules. Open jars and clear bottles are usually unsuitable.
How long should stability testing run for growth factors?
At minimum 3 months accelerated and 12 months real-time. Track functional activity, not only chemical concentration.
Related: stability in cosmetic formulations, evaluating a growth factor supplier, best delivery system for growth factors.