I've been on TV twice in my adult life (we're not counting the Brownie troop's trip to the Sheriff Scotty show here). Both times, I did not wear make-up--boy was that a mistake!--but I did pre-medicate with beta-blockers. As a result, I appeared pathetically pale and totally calm.

Beta- blockers tone down the effects of the sympathetic nervous system. This is the 'fight or flight' arm of the involuntary nervous system which is driven by norepinephrine or adrenalin. Originally developed for hypertension, these drugs were subsequently found to be very useful for stage fright. Several patients of mine who are attorneys take them before they appear in court, and some sales reps use them to calm the pre-presentation jitters.

Evidence suggests that they may someday be used to prevent metatstases from cancer. In particular, studies suggest that many breast, colon, and prostate cancer cells have beta-adrenoreceptors on their surfaces. Men on beta-blockers were 18% less likely to contract prostate cancer in one Canadian study, and propranolol prevented metastases in a mice tumor model.

One cancer biologist noted:

These data imply that emotional stress may contribute to the development of cancer and may also reduce the effectiveness of cancer treatments.