according to the article, the chemical happens in digestion in e

but not everyone smells it.
"But only about one-quarter of the population appears to have the special gene that allows them to smell those compounds. So the issue isn't whether or not your pee is smelly; it's whether you're able to smell it. If you smell a funny fragrance in your urine after you eat asparagus, you're not only normal, you have a good nose."