Something i have always wondered about. When you take a tablet for a certain part of the body, eg the pancreas or the liver say, how the hell does the body know how to send it to the correct place?
It doesn't actually send the medicine to any particular place. The chemicals get absorbed through the digestive system and travel throughout the body via the blood.
If you take glucosamine, the blood will take it to all parts of your body and where a joint is short of this it will be absorbed by the joint lining. While glucosamine is fairly safe to take you should still see a doctor first.
Because medicines travel all though your body it usually also effects organs/tissue other than the target problem, known as side effects. Thus, you should never take them if you're not sure of the side effects. Never buy over the counter medicine except from pharmacies which have a qualified pharmacist in attendance so you can ask questions.
As wilwood says , the medication travels all around the body .
That is why the information leaflet that comes with medication , lists a lot of possible side effects , as the medication interacts with different parts of the body .
strictly speaking, drugs don't have side effects - they just have effects. You have to find one that has effects you want and doesn't have effects you don't. As Berti says, read the manual, and if your GP is prescribing, make sure he knows of everything that might be wrong with you, not just the thing you're seeing him about at the moment.