How to make your urine blue

How to ingest methylene blue to make your pee blue. Link (Thanks, Phil!)

Reader comment:

Russell says:

I've been an avid reader of the Boing Boing blog for some time, it's good stuff.

I saw the 'turn urine blue' post and remembered seeing something about methylene blue on an MSDS that would probably be worth mentioning with this - it may have had a hand in some birth defects when injected amniotically. Fairly harmless stuff unless you're pregnant though, and probably not to dangerous when ingested even then, but for more info there's a report here.