Urine whitens clothes.

It’s True!

Healthy urine is 95% water, 2.5% urea, and 2.5% salts, minerals, enzymes, and other compounds. As urine ages, the urea breaks down and ammonia is released. It takes weeks of aging for urine to form enough ammonia for a significant laundry session, but that ammonia, an alkaline and slightly corrosive property, neutralizes dirt and grease, which are acidic.

Fun fact: The Romans used urine as a cleaning agent centuries ago.

According to passages from A Dictionary of Greek and Roman Antiquities, Romans collected urine in closed tubs called fullos. The urine-filled fullos were left to stand for weeks to produce enough ammonia for cleaning purposes. The ammonia was then transferred to a larger tub and mixed with water and wood ash, which contains natural lye, before the clothes were added. Fullers trampled and scrubbed clothes in the urine-filled tub, and then rinsed them with fresh water.

Thanks to detergent, we don’t have to clean our clothes in bodily fluids, but urine therapy is still popular for many other uses.

  • Aged urine also whitens teeth, a method favored by ancient Romans and Spaniards. The famous Roman poet Catullus wrote a scathing poem about Celtiberian (modern-day Spain) leader Egnatius, stating, “Now in the Celtiberian country, the natives rub their teeth and red gums every morning with that they have urinated. So that the cleaner your teeth are, the more urine you are shown to have drunk.” Ouch!
  • The nitrogen in urine can be used to make saltpeter, a crucial ingredient in gunpowder, according to Saltpeter, which quickly oxidizes and allows gunpowder to catch fire, is extracted from filtered urine.
  • In the process of making leather, tanners soak animal skins in aged urine to quickly remove hair fibers. Similarly, some hair removers such as Nair and Veet also included urea in their list of ingredients.
  • Scientific American says urine is great for fertilizing gardens thanks to its large amounts of nitrogen, potassium and phosphorus.
  • Urine is a popular home remedy for acne, psoriasis and eczema, acccording to anecodes from They say rubbing a baby’s wet napkin soaked in one’s first morning urine clears the skin of acne-causing impurities.