Thickening and Adding Ingredients to Sulfate-Free Shampoo Base

Based on the staff's replies:

Thickening Agents:
The Sulfate Free Shampoo Base already has some viscosity. You can try adding water first. If more thickness is needed, you can use salt (Sodium Chloride) up to 1%. If that's still not enough, consider using SugarThick (1-5%) or EasyThick (1-5%). Sodium Lactate and Zinc PCA, being electrolytes, can also help thicken the base.

Adding Other Ingredients:
Ingredients like Disodium EDTA, Zinc PCA, Biotin, Vitamin B5 (Panthenol Pro-Vitamin B5), and Phenoxyethanol SA are generally compatible with the base. The staff could not confirm compatibility for Egg Protein and certain herbal extracts (like butterfly pea, ginger).

Regarding choosing an additional ingredient for maximum effectiveness, the staff asked for clarification on what kind of effectiveness you were looking for. However, in your revised formula, you included Pure Keratin, Hydrolyzed rice protein, and Allantoin, and the staff confirmed that Disodium EDTA, Zinc PCA, Vitamin B5, and Phenoxyethanol SA can work in the formula, implying compatibility for those ingredients from your list.

Cooling Agent:
For a cool sensation without the potential issues of menthol, CoolTouch™ (Menthyl Lactate) at 0.1-1.0% is recommended.

Regarding your revised formula questions:

1. SiliWater (Dimethicone Copolyol) will not block or prevent the absorption of vitamins, proteins, or other nourishing ingredients in the shampoo.
2. Adding fragrance does not necessarily require Flora Solve if you don't need a clear product. You can mix the fragrance directly into the Sulfate Free Shampoo Base, which will result in a cloudy formula. Flora Solve or another emulsifier might be needed if you add a large amount of fragrance or oil.
3. Flora Solve does not have negative effects on the other ingredients listed in your formula.