Have you ever been sold a treatment on the promise it will repair, reconstruct or restore your damaged hair permanently? I'm sure this doesn't happen often because the promise is empty. While a treatment of any sort may well improve the feel and manageability of your hair temporarily, it will have no permanent effect of any sort. Ever.
Damaged hair is damaged hair unfortunately.
But don't feel cheated. Treatments are still amazing products for, as I stated earlier, make your hair feel stronger, softer and your hair will become much more manageable for a short time after they have been used on your hair. A long time if we're talking Keratin Treatments which are a semi-perminent type.
When you use any sort of treatment, from protein kinds to moisturising kinds, it not only improves the feel and manageability of your hair but it also protects your hair from the day to day damage of sun, wind and styling. When you regularly treat your hair well, it will grow out healthier.
So don't hope for improved hair after one treatment. Unfortunately you will be disapointed