Grey Hair Covering Shampoo Formula

To formulate a semi-permanent shampoo for covering grey hair, you can use a semi-permanent colorant designed for shampoo formulations, such as SemiColor - Wood Black. This type of colorant gradually adds color to the hair with each wash.

Here is a sample formula based on the product information:

Sample Formula

• Water: up to 100%
• Surfactant (Amphoteric or Non-ionic type, e.g., Cocamidopropyl Hydroxysultaine or Coco Glucoside): ~20%
• Hydroxypropyl Methylcellulose (for thickening): ~1.0%
• Benzophenone-4 (UV protection for color): ~0.2%
• ColorFix™ (helps color adhere better): ~0.6%
• Mild Preserved Eco (Preservative): ~1%
• SemiColor - Wood Black: ~0.2% (can use 0.1-1.0%, but >0.2% may stain)
• Triethanolamine (to adjust pH): Add as needed to adjust pH to approximately 9.

Important Notes

• This formula uses a semi-permanent colorant. It will not provide permanent grey coverage like traditional hair dye. The color will build up gradually with repeated use.
• Use an Amphoteric or Non-ionic surfactant. Avoid anionic surfactants as they can interfere with the colorant.
• Adjust the pH of the final formula to around 9. A higher alkaline pH helps the color adhere better, but do not exceed pH 9 as the color may degrade.
• ColorFix™ is recommended to help the color stick to the hair better and last longer.
• Mix SemiColor - Wood Black in water heated to 70-80°C to help it dissolve before adding to the formula.

This formula provides a starting point for a color-depositing shampoo aimed at reducing the appearance of grey hair over time.