Combining Peptides in Formulations

When combining multiple peptides like Copper Peptide and Nonapeptide-1 in a cosmetic formulation, the appropriate total percentage depends on the specific peptides used and their recommended usage rates.

• Copper Peptide (GHK-Cu): Recommended usage is typically 1-3% for solutions (like Copper Peptide (GHK-Cu, Copper Tripeptide-1) (1000ppm Solution) or Copper Tripeptide 10x (GHK-Cu, Copper Tripeptide-1) (10000ppm Solution)) and 0.01-1% for powder form (like Copper Peptide (GHK-Cu Copper Tripeptide-1, 1:1) Powder).
• Nonapeptide-1: The recommended usage rate is typically 1% (as seen with Pep®-Radiance (Nonapeptide-1)).

It is generally recommended to follow the suggested usage rate for each individual peptide. While there isn't a strict universal rule for the total combined percentage of all peptides, you can often use each peptide at its recommended concentration simultaneously.

For example, if you use Copper Peptide solution at 2% and Nonapeptide-1 at 1%, the total peptide concentration would be 3%. This is generally acceptable as long as the individual peptides are used within their recommended ranges.

However, it's important to consider the overall formulation and the total concentration of all active ingredients. Using very high concentrations of multiple potent actives, including peptides, can potentially lead to:

• Reduced stability of the formulation.
• Potential interactions between ingredients.
• Increased risk of skin irritation or sensitization.

Therefore, while you can often use each peptide at its recommended individual rate, avoid exceeding the maximum recommended percentage for any single peptide. Starting with lower concentrations when combining multiple actives is always a good practice to test for compatibility and skin tolerance before increasing the percentage.

Using an excessively large amount of peptides beyond the recommended levels is generally not necessary for efficacy and could potentially be detrimental to the skin or the product's stability.