Some time ago I heard about the existence of a substance that some human are not able to smell. This means if they try to smell it, they don't "feel" any scent... like smelling pure water or pure air.

PS: I heard it during a TV show about flowers but I don't know absolutely if it effectively rely on the flower-world, so I don't know if this information can help

  • 4
    Interesting question. Though I am not sure to which substance you are referring. Two years ago, there was a very interesting article in Nature Neuroscience called "The missense of smell: functional variability in the human odorant receptor repertoire" by Mainland et al. Without wanting to go into too much details, they showed that there is a huge genetic variation in olfactory perception (they gave the example of more than 30% difference in odorant receptor alleles between 2 persons) between individuals. So probably, there are >1 substance that some individuals can smell and other not. BR Aug 26, 2016 at 14:02
  • 4
    Here the link to the article: nature.com/neuro/journal/v17/n1/full/nn.3598.html. Unfortunately it is not open access. I could convert this comment to an answer and give some extracts of the article but maybe someone more updated than me will bring some acurate answer (with a precise name of the substance you are referring to) to your question. Good luck. Best regards. M. Arrowsmith. Aug 26, 2016 at 14:04
  • Asparagus gives urine a particular odor. Not all people, however, can smell it.
    – BillDOe
    Jan 27, 2017 at 21:46

1 Answer 1


As mentioned in a previous answer asparagus has a particular amino acid, asparagine, that not all people can smell.

There are also some medical conditions where particular people can't smell anything. For example, people with Kallmann syndrome often have complete anosmia (inability to smell) because the olfactory receptors do not migrate to the proper location during development.

  • Just to clarify: though asparagus contains asparagine, asparagine is made by the body, though probably not in sufficient quantity to be detected by odor in our urine.
    – BillDOe
    May 3, 2018 at 21:02
  • Reference(s) needed please :)
    – DoctorWhom
    May 4, 2018 at 8:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.