Kidneys..........................................

So I know that eg. hormones/medicines/barbiturates/paracetm… etc. is broken down by enzymes in the liver.

Then I read "Urine is useful for detected waste products of metabolism eg. medicines/drugs/hormones"

I didn;t think that medicines/drugs would be exrected in urine as surely they are useful?
Or are they just excreted after they have "been used/done their job"?

The body has a limit on the amount of substances it can absorb during a given time period. All substances will be utilized by the body to the highest efficiency it can but if there is a concentration of substance that exceeds the "absorption threshold" of the body, then it will be excreted in urine.

Additionally, this is why it is common for you to observe a visual change in your urine after you take a multivitamin. Your body cannot absorb ALL of the nutrients and they cannot all be stored, so they are excreted.

Yes!... NO!!!
Uhh, I don't know.. MAYBE!!!
leave me alone :( !