Lavender has been used cosmetically and medicinally throughout history. Lavender is cultivated around the world and the fragrant oils of its flowers are used in aromatherapy, baked goods, candles, cosmetics, detergents, jellies, massage oils, perfumes, powders, shampoo, soaps, and tea.
The dried flower heads are perfect for use in crafts for scented pillows/heated bags, to calm and soothe.
Lavender has been taken by mouth as a tea prepared from 1 to 2 teaspoons (5 to 10 grams) of leaves steeped in 1 cup (250 milliliters) of boiling water for 15 minutes. Lavender oil has been used in aromatherapy (inhaled) and massage therapy (applied on the skin).
Interactions with Herbs and Dietary Supplements: Lavender used as aromatherapy or by mouth may increase the amount of drowsiness caused by some herbs or supplements, such as valerian. Caution is advised while driving or operating machinery.
See what Wikipedia says:
http://en.wikipedia.org/wiki/Lavender