Does applying lemon on the hair really make it lighter ?

Lemon, as bleach: Hi Haythoum YES ~ The lemon juice acts like an accelerant to the sun's natural hair lightening abilities. It's magnifying the amount of lightening the sun can do, which creates the subtle highlights. It may fade with time, but treat it like permanent hair dye. Luckily, the color change is so gradual that it is very easy to control. (INTERNET)