There are some excellent oral preflushers out there that cause a much greater flush than niacin, a more sustained flush than niacin and dont cause the uncomfortable itchiness.

L-arginine, the precursor for the potent dilator nitric oxide is the key ingredient.

Even though this is over the counter, I would definitely take it in to your doctor first and see if it would be fine for your specific case (also have them measure your blood pressure during the test).

ArginMax looks to be the most potent. All four ingredients are potent dilators and the L-Arginine at those levels plus the Asian Ginseng should bring out the red in everyone:

L-Arginine (3000mg) 3 g*

Korean (Asian) Ginseng Extract (aerial part and root) 100 mg*

American Ginseng (root) 100 mg*

Ginkgo Biloba Extract (leaf) 50 mg*