I am an adult, and I want to be taller. I know about many medicines which claim to treat stunted height. Is there any truth behind these?
Unfortunately, height is genetically based.
At 24 years old, it is unlikely that you will grow more, but the only way to know for sure is if you have an x ray done of the growth plates in your bones to see if they have disappeared. If they have, then there really is no natural way to increase height.
There are surgical procedures (See this article) where you can potentially add a few inches, but they are very costly (The procedure described in the article cost ~ $90,000 US dollars), and they are reported to be very painful, long (3+ months) and require extensive rehabilitation and physical therapy to be successful. According to the article, most places that do the procedure use it primarily for physical afflictions such as dwarfism, and do not recommend it for purely cosmetic reasons.
The only known non-surgical method of gaining height at this age is to go into space. Without the pull of earth's ground level gravity astronauts have been shown to gain height.
Astronauts in space can grow up to 3 percent taller during the time spent living in microgravity, NASA scientists say. That means that a 6-foot-tall (1.8 meters) person could gain as many as 2 inches (5 centimeters) while in orbit.
However, this height is lost once earth's full gravity is restored.