Ancient Romans used pigeon droppings and vinegar to bleach their hair blonde.

In the first and second centuries AD, Romans admired the light hair of people from northern Europe. They created mixtures to copy this look. Pigeon droppings contain nitrogen and uric acid. When these chemicals are put on hair and sit in the sun, they cause a chemical reaction called oxidation.Oxidation breaks down melanin, which is the natural pigment that makes hair dark. Romans also used a soap called Batavian foam made from goat fat and wood ashes. These substances were very harsh and alkaline. They often damaged the hair's protein structure, called keratin.The process was dangerous and could cause scalp burns or hair loss. Many people ended up wearing wigs made from the hair of prisoners to hide the damage. Archaeologists have found jars in Italy and Britain containing the remains of these hair-lightening pastes. These findings prove that Romans went to extreme lengths to follow beauty trends.