Most drugs are excreted from the body through the kidneys, which play a vital role in filtering blood and removing waste. When we take medicines, the body processes them through metabolism and eventually eliminates them to avoid buildup. The kidneys filter blood and remove drug substances and their byproducts via urine.

The process starts with the liver breaking down drugs into smaller parts, and then these parts travel to the kidneys. The kidneys use tiny filters called nephrons to remove unwanted substances. This is the main route for most drugs, although some may exit the body through sweat (skin), bile (gallbladder), or exhalation (lungs).

Here’s why the other options are less common for drug excretion:
- **Skin**: Drugs can be lost through sweat, but this is minimal compared to kidney excretion.
- **Gallbladder**: It releases bile into the digestive system but is not the primary route for drug removal.
- **Lungs**: Only some volatile substances and gases are excreted this way.

Understanding drug excretion is important for medical treatments and dosage adjustments, especially for patients with kidney problems. It ensures that drugs do not accumulate to harmful levels and work effectively.

In summary, the kidneys are the main organs responsible for removing most drugs from the body, making them essential for maintaining health after medication.