Sometimes smoothening treatment fails due to different factors beyond control like henna application stop the chemical penetration to hair shaft. If smoothening treatment fails and you don’t get desired results then don’t rush for smoothening treatment immediately. Smoothening is a chemical treatment which makes hair weak ,due to this wait for at least 1-2 weeks before smoothening rework. Further after second treatment go for keratin treatment which laminates the hair shaft and makes hair strong and thicker.