My hair became dull and brittle. I have tried many shampoos, but all of them bring short-term improvement. I need a black seed oil. Many reviews say this oil successfully copes with strengthening hair and split ends of strands. It eliminates excessive dryness, brittleness. The easiest way to restore hair is to add the product to shampoo. For 100-150 ml of shampoo, use 2-3 drops of oil.