An infusion of lavender is claimed to soothe and heal insect bites. Bunches of lavender are also said to ward off insects. If applied to the temples, lavender oil is said to soothe headaches. Lavender is frequently used as an aid to sleep and relaxation: Seeds and flowers of the plant are added to pillows, and an infusion of three flowerheads added to a cup of boiling water are recommended as a soothing and relaxing bedtime drink. Lavender oil (or extract of Lavender) is claimed to heal acne when used diluted 1:10 with water, rosewater, or witch hazel; it is also used in the treatment of skin burns and inflammatory conditions (it is a traditional treatment for these in Iran and other former Persian regions).
There is scientific evidence to support the effectiveness of some of these remedies, especially the anti-inflammatory effects, but they should be used with caution since lavender oil can also be a powerful allergen. Ingesting lavender should be avoided during pregnancy and breastfeeding.
Topically, lavender oil is cytotoxic. It increases photosensitivity as well. A study demonstrated that lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25%. Linalool, a component of lavender oil, reflected the activity of the whole oil, indicating that linalool may be the active component of lavender oil.