Shampoo Formula Review for Dry and Damaged Hair

The shampoo formula you provided is well-structured and includes several ingredients beneficial for dry and damaged hair. The selection of mild surfactants and the inclusion of conditioning agents are suitable for this hair type.

Here's a review of the formula and suggestions:

Assessment of Ingredients and Percentages

• Surfactants (Sodium Lauroamphoacetate, Cocamidopropyl Betaine, Cocamide MEA, Sodium Lauroyl Glutamate, Lauryl Glucoside): The combination of these surfactants, including gentle amphoteric and non-ionic types like Cocamidopropyl Betaine and Lauryl Glucoside, is a good choice for minimizing dryness compared to harsher sulfate-based systems. The total surfactant concentration appears reasonable for a typical shampoo.
• Conditioning Agents (Camellia Seed Oil, Polyquaternium-7, Guar Hydroxypropyltrimonium Chloride, Panthenol, PCA): This is a strong aspect of your formula for dry hair. Camellia Seed Oil provides nourishment, while Polyquaternium-7 and Guar Hydroxypropyltrimonium Chloride are excellent conditioning polymers that improve wet and dry combability, reduce static, and leave hair feeling soft. Panthenol (Pro-Vitamin B5) and PCA are effective humectants that help attract and retain moisture in the hair.
• Other Ingredients (PARFUM, Citric Acid, Phenoxyethanol): Fragrance adds scent. Citric Acid is essential for pH adjustment. Phenoxyethanol is a preservative.

Suggestions for Adjustment

Based on the formula and typical requirements for dry/damaged hair:

• Conditioning Agents: The current levels of conditioning polymers (Polyquaternium-7 and Guar Hydroxypropyltrimonium Chloride) and Camellia Seed Oil provide good conditioning. If you desire even more intense conditioning for severely dry or damaged hair, you could consider slightly increasing the total concentration of the conditioning polymers (e.g., from 1.2% total to 1.5%) and/or increasing the Camellia Seed Oil percentage (e.g., from 0.6% to 0.8-1%). However, increasing these too much can affect foam, viscosity, and rinse-off feel, so test thoroughly.
• Citric Acid: The 0.04% is likely a starting point. You must adjust the amount of Citric Acid to achieve the desired final pH of your shampoo. For hair products, a pH between 5 and 6 is generally recommended to help keep the hair cuticle smooth and reduce frizz. Use pH paper or a pH meter to measure and adjust gradually.
• Preservation (Phenoxyethanol): Phenoxyethanol at 0.3% is on the lower end of typical usage rates (often 0.5-1.0%). While it provides antibacterial protection, Phenoxyethanol alone is not always fully effective against fungi. Depending on the specific type of Phenoxyethanol used and the overall formula composition, you may need to increase its concentration slightly (within recommended limits) or consider using a broad-spectrum preservative blend (like one containing Phenoxyethanol with Caprylyl Glycol and Sorbic Acid) to ensure adequate protection against a wider range of microorganisms. It is crucial to perform challenge testing on your final formula to confirm the preservative system is effective.
• Water (Aqua): Ensure that Aqua is added last to bring the total formula percentage to 100% after all other ingredients have been measured and added.

Conclusion

Your formula is a solid foundation for a shampoo for dry and damaged hair. The ingredient choices are appropriate. The primary adjustments you should focus on are adjusting the Citric Acid to achieve the correct pH and verifying the effectiveness of your preservative system through challenge testing, potentially adjusting the Phenoxyethanol concentration or type if needed. Minor increases in conditioning agents are optional based on desired performance.