How to Lighten Hair With Lemon Juice. Blondes are always looking for ways to keep their hair blonde or lighten up the darker "dishwater" blondes. One method of lightening up blonde hair is by using lemon juice. Use the following guidelines to help you know how to go about lightening your hair with lemon juice.
Work the lemon juice into your hair. Make sure that you work the lemon juice evenly across the top of your hair, along your part areas, hair lines and crown areas.
Leave the lemon juice in your hair while you are out in the sun for about an hour. The lemon juice contains lots of acid, so you really don't want to expose your hair to both extreme sun and the acid in the lemon juice for long periods of time. Rinse the lemon juice out of your hair.
Repeat the process of applying the lemon juice in your hair and being in the sun as many times as necessary to notice a difference in the blonde color. The lemon juice should eventually give your blonde hair highlights and streaks of lighter natural looking color. This process may take several weeks to achieve a real difference in coloring.