Could you check these sentences?
7. We have added vitamin E to our Soft&Shiny shampoo and conditioner.
Our Soft&Shiny shampoo and conditioner had been added vitamin E for us.
You may not notice the effect of Silky Hair immediately.
The effect of Silky Hair may not be noticed immediately by you.
People know the effect of our products.
The effect of our products is known by People.
You should apply Sweet Hair mask at least once a week.
At least once a week Sweet Hair mask should be applied by you.
Thanks in advance.