Stunted Growth (height)

The use of some steroids can possibly stunt the growth potential of people who have not finished growing. This is only possible with certain steroids, and not with others. In fact, certain steroids have been used in clinical settings to improve growth rates in children. It is probable that the premature closure of the epiphysial cartilage, which is most likely caused by aromatizable steroids, will lead to a possible growth inhibiting effect, and could ultimately result in a shorter adult height. This most likely an irreversible side effect, as the growth plates would have sealed and can not "re-open". Anavar (Oxandrolone) has been used to improve the height of growth stunted children, and it is probable that most DHT-derived steroids could also be used for this purpose as could certain anti-estrogens.

Speaking in broad terms, growth stops at the end of the teenage years...there is almost no chance to keep growing.

This is because lengthening of a bone occurs at the epiphyseal growth plates (called the "growth plates" in common parlance), the remnant of the cartilage model. It's capable of proliferating. In 99.9% of humans, the process of bone elongation ends at around the mid to late teen years. At this point, the growth plates are obliterated and disappear, after which no more elongation (typified by an increase in limb length, height, etc...) can take place. Elongation of the bone occurs here and at a second epiphysis at the end. The proliferation of the cartilage happens very quickly, actually fast enough to keep ahead of the bone generation that´s "chasing" it, called ossification, which is just the replacement of cartilage by bone. As long as the cartilage growth "stays ahead" of the bone, you grow taller, as bone replaces cartilage. When the bone finally catches the cartilage (because the cartilage slows its growth rate, not the bone), it ossifies, and "seals" the growth plate.

Here´s a growth plate picture, enhanced by radioactive dye (GP= Growth Plate), so you can sort of see the bone "catching" up with the cartilage.

(Human Anatomy and Physiology, 6th Edition, John W. Hole jr., Wm. C. Brown Publishers.)