Why is my urine bright yellow?

Bright yellow urine is often harmless, and common causes include:

1. B vitamins, especially riboflavin (vitamin B2) — This is a very common reason after a multivitamin, B-complex supplement, or fortified drink/food. Riboflavin can make urine look vividly yellow.

2. Mild dehydration — When you’re not drinking enough fluids, urine becomes more concentrated and can look darker or brighter yellow.

Other possible causes include certain medications and supplements.

What to do:

• Check whether you recently took a multivitamin, B-complex, energy drink, or other fortified product.
• Drink some water and see whether the color lightens over the next few hours.

Get medical advice if the urine stays unusually bright/dark, or if you also have pain, fever, back pain, burning, blood in the urine, or cloudy urine.

This information is for educational purposes and not a substitute for medical advice. Bright yellow urine from supplements is often harmless, but if you’re unsure or have other symptoms, check with a clinician.