I am trying to find a SAFE way to change the colour of my urine, from what I have read online, Methylene Blue is relatively safe, and will change urine to blue or green. Is it safe? Can I put this in a food or drink? If so what are safe amounts? If not does anyone know a way to change the colour of urine safely?


closed as off-topic by Michael DM Dryden, Freddy, Abel Friedman, Martin - マーチン, t.c Oct 16 '14 at 6:00

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Personal medical questions are off-topic on Chemistry. We can not safely answer questions for your specific situation and you should always consult a doctor for medical advice." – Michael DM Dryden, Freddy, Abel Friedman, Martin - マーチン, t.c
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  • $\begingroup$ This would definitely be a question For S.E. Biology, But I have no idea what would be the motivation for this. $\endgroup$ – John Snow Oct 16 '14 at 5:18
  • $\begingroup$ is that for lightsaber battles? just have a day with less food and drink, and then drink red coloring derived from beetroots to an equivalent of about 4-5 beetroots and food and drink lots and lots... of water. ) $\endgroup$ – com.prehensible Feb 25 '15 at 18:53

Lots of common foods can colour urine; beets, berries, carrots, asparagus (as well as making it smell) and rhubarb to name a few.

A google search will give you plenty of references, but to get you started, try the urine colors website.

Methylene Blue (CAS 61-73-4) in concentrated form is harmful if swallowed and is a known irritant. Methylene Blue solution (~1%) is also harmful if swallowed, and has reported warnings which include:

  • May cause gastrointestinal irritation, discoloration of oral mucosa, irritation of lips, mouth and throat, paleness of complexion, lack of coordination or drowsiness
  • Effects may be delayed. Laboratory experiments with methylene blue have resulted in mutagenic effects. Repeated contact may cause corneal damage. May cause adverse eproductive effects.

Eat lots of carrots or liquorice instead.

  • 1
    $\begingroup$ Nevermind the CNS effects of methylene blue. They are perceptible, and it's what gave people the idea to develop phenothiazine drugs. $\endgroup$ – Abel Friedman Oct 16 '14 at 4:58

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