Hello, can't mix directly.
Protec™ UV will must be dissolved in oil before it can be added to the formula. Since the shampoo is water-based, it will have to mix the oil with the water, which will cause complications. Member's shampoo Packed in opaque bottles or clear bottles. If the bottle is clear, it is recommended to use
Benzophenone-4 0.5% instead, if the bottle is opaque, no UV protection is needed.