How severe is your allergy?  What happens?

The pepper is a very essential part of the Master Cleanse.  If you don't use it, you will not get the full cleansing effect.  You'd just be juice fasting.

By all means, if you are allergic to pepper, and you decide to go ahead with using it be very cautious.  I tell everyone who is going to try the MC for the first time not to start out with the 1/10th tsp that is recommended.  I tell them to just sprinkle a little pepper into the first couple lemonades and then gradually start working their way up to 1/10th or even more.  I'm currently using 1/4 tsp per 10 ounce glass.

Again, you will still get some benefit from the fast without using the pepper so it would still be worthwhile.  I don't have my book handy as I loaned it to someone to read, but I think I remember that the pepper helps to cleanse the body of excess mucous.

Whatever your decision is, good luck to you!

Tiffany