It's an ampoule you can trust and use.
I have been dyeing my hair periodicly for over 20 years due to having genetic grey hair.
If you add one ampoule each time, it reduces a lot of damage to the hair.
At the hair salon, they put in one that is cheaper than this but the treatment was very expensive.
With that price, I bought the ampoule myself and am currently using it. I am very satisfied!