May 25, 2026, 4:02 pm | Read time: 3 minutes
“It smells like asparagus in the restrooms… Spring, spring everywhere!” This saying describes asparagus season in the spring months–and specifically the peculiar, strong odor that urine takes on after an asparagus meal. FITBOOK explains the phenomenon and why not everyone is affected.
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Why Urine Smells Strange After Eating Asparagus
The typical smell of urine is due to the asparagusic acid found in asparagus, or more precisely, its sulfur-containing breakdown products. Sulfur is known to have an unpleasant odor.
So technically, you can’t blame the asparagus itself, but rather an enzyme in the body that breaks down the sulfur-containing compounds of asparagusic acid.
Not Everyone’s Urine Smells After Eating Asparagus
However, not everyone can smell the asparagus odor in the restroom. Some people lack the enzyme to break down asparagusic acid, so the strong-smelling breakdown products never form. As a result, they don’t experience the typical asparagus urine smell. The reason people react differently to asparagus is likely hereditary.
There is also a second group of people who are spared the asparagus smell in the restroom. They do produce the odor compounds but cannot perceive them themselves. In other words, the sulfur compounds are present–but the person urinating doesn’t smell them. Why is that? In these individuals, a gene mutation in the olfactory receptors prevents the peculiar smell from being detected.1 This is referred to as a specific anosmia, or smell blindness.2
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Can You Prevent the Asparagus Urine Smell?
If you notice a strange smell in the restroom after eating asparagus, there’s not much you can do about it. Drinking plenty of fluids helps to flush the breakdown products out of the body more quickly. However, this doesn’t significantly reduce the unpleasant smell.
But even if you find the urine smell unpleasant, it’s not an indicator of any harmful health effects. On the contrary, asparagus is known to be very healthy.
Supplements Can Color Urine
By the way, since asparagus has a diuretic effect, there are also supplements with asparagus extract. These products can also affect urine–but in a different way. The urine can change color after taking the supplements. However, this is less due to the asparagus and more to other ingredients, such as vitamins and plant extracts.
For example, high doses of vitamin B2 (riboflavin) can cause urine to glow yellow or orange. Iron can also lead to reddish-brown urine.3
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Other Foods Also Cause Unpleasant Urine Odor
Besides asparagus, there are other foods that can affect the smell of urine. This includes coffee, which also produces sulfur-containing compounds when broken down in the body. Alcohol can also have this unpleasant side effect, as dehydration of the urine leads to a stronger smell.
When Unusually Smelling Urine Can Be a Warning Sign
A change in urine odor after eating or drinking is usually harmless and quickly passes. However, if the strong or unusual smell persists for several days without asparagus or coffee being involved, you should be alert.
- A pungent, ammonia-like smell can indicate a urinary tract infection or bladder infection, as bacteria break down the urine.4
- If the urine smells noticeably sweet or fruity, reminiscent of ripe fruit or nail polish remover, it’s a typical warning sign of undiagnosed diabetes mellitus.5
- Kidney failure can also lead to changes in smell, such as a urine-like body odor.6
If any of these points apply to you, a visit to the doctor is advisable.