A recent study from Pakistan had found that boys who smoked marijuana had lower levels of growth hormones and higher levels of hormones associated with puberty, such as testosterone and luteinizing hormone (LH. By the age of 20, non-smoking boys were n average 4 kg heavier, and 4.6 inches taller than their smoking counterparts. Levels of the stress hormone cortisol were also notably higher in marijuana user. Besides the health risks of higher cortisol, an earlier onset of puberty increases the chances of substance addiction, as the critical period of adolescence is entered at a less emotionally mature age.
“Smoking marijuana may cause early puberty and stunts growth in boys,” www.alphagalileo.org, May 18, 2015