Nettle stings contain acid (formic acid) but they also contain histamine and other chemicals. The exact details are still unknown but it is the histamine that causes the initial reaction when you are stung. Dock leaf sap contains a natural antihistamine, which helps to ease the stinging sensation.
Also know, do all stinging nettles sting?
Stinging nettles have developed stinging cells as an adaptation to deter herbivores from eating them. The plants contain long, thin, hollow hairs that cover the majority of the stem and the underside of the leaves. Nettle stings contain acid (formic acid) but they also contain histamine and other chemicals.
Which acid is present in nettle leaves?
Urtica dioica (stinging nettle) Formic acid is one of the chemicals present in nettle stings, along with histamine and acetylcholine. This chemical cocktail is delivered via stinging hairs with tips that break off when touched.