Is it obligatory to wash the right and left sides of the body three times during ghusl janabah, or is this repetition specific only to the head?

It is not obligatory to wash the head or any body part three times when performing ghusl (ritual bath) after major impurity. The obligation, according to the preponderant opinion, is to ensure that water covers the entire body, even with a single wash. It has not been narrated that the Prophet, peace and blessings be upon him, washed his entire body three times. Washing three times in ghusl is considered a sunnah (recommended act).