How long does it take for poppy seeds to show up in your urine stream?

Varies: It depends on whether you ate them with fatty food (absorption slowed down) or just by themselves and in what quantity. Earliest it would show up in your urine would be approx 4-8 hours and the average it would remain there would be 48 hours. Ingesting large quantity could mean--potentially- a test could remain positive at upwards six or more days though unlikely.