"Cold compresses of Peppermint, or Peppermint and Lavender, applied to the forehead and temples will relieve headache, and sometimes migraine, though not all migraine sufferers can tolerate the smell once an attack has begun. The compresses are most effective if they can be applied at the first sign of pain. Both these oils are painkillers, but while Peppermint is stimulant, Lavender is sedative. The combination of stimulant and sedative is found in many commercial pain-killing preparations (asprin, phenatacin and caffeine for example), but with the important difference that essential oils do not merely suppress the pain, but work on its causes, such as blocked sinuses, a congested liver, or mental fatigue."
Davis, P. Aromatherapy an A-Z, (2000), p. 234