Generics use different fillers, dyes, etc, and may come in different forms--as a capsule rather than a caplet, for example. And every generic supplier brings a different x-factor (dozens of then actually) into the mix. You may be sensitive to any one of these.

Part of what you're paying for in a Brand Name is lower odds that you'll be getting an ingredient that a large percent of the public has issues with.

If one generic bothers you, you might ask your pharmacy to dispense a generic from a different pharmaceutical house to you. That might solve the problem, if you're lucky.

Roadie