Asparagus Odor Detection

Your result, the one DNA position behind it, and what the research says.

5/10 confidence.

About Asparagus Odor Detection

Most people who eat asparagus produce the sulfur compounds responsible for its famous after-effect, and most people can smell them. Both halves vary: in the study behind this card a few people produced too little to be detected, and a larger number could not smell it even in someone else's sample. What this card reads is the smelling half. This position sits in a dense cluster of olfactory receptor genes on chromosome 1. It falls between two of them rather than inside one, so it marks the stretch of DNA rather than altering a receptor itself, and the receptor that actually responds to these compounds has not been identified. What the version you carry shifts is how readily you pick the smell up, rather than switching the sense on or off. People who cannot smell it are genuinely unable to, not merely unobservant, which is why the topic produces such confident disagreement.

Good to know: People differ both in producing the compounds and in smelling them. Being unable to smell it is a receptor difference, not inattention. The non-detecting version is the more common one globally.

Fun fact: Marcel Proust and Benjamin Franklin both wrote about the asparagus effect, and Franklin's remark dates from around 1781, so the argument has been running for more than two hundred years.

Discovery: The link between this stretch of smell-receptor genes and asparagus odor detection was reported in 2010.

The Variant

The single variant behind this trait

Gene: OR2M7

Variant (rsID): rs4481887

Location: Chr 1:248,333,561

dbSNP rs4481887

The studies

Excretion and perception of a characteristic odor in urine after asparagus ingestion: a psychophysical and genetic study (Pelchat ML et al., Chemical senses, 2011)

Other lifestyle traits

Bitter Taste: Three linked changes in a bitter taste receptor that set how strongly you taste the bitter compounds in broccoli, kale and Brussels sprouts.

Cilantro Tastes Like Soap: A variant in a cluster of smell receptor genes, one of which responds to the aldehydes in cilantro, linked to whether the herb tastes soapy to you.

Spice Sensitivity: A change in the receptor that detects capsaicin, the compound that makes chili taste hot, linked to how intensely you feel that burn.

Back to All Traits

Content updated September 2026.

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