I am lactose intolerant and cannot have caffeine because it makes me feel really bad. what supplement can i take to build muscle?

Inconsistent info: Caffeine does not build muscles. Intolerance to caffeine is not related to lactose intolerance. To build muscles you need to do exercise, especially weight training. You can get the protein needed for muscles from many sources, e.g., beans, legumes, lentils, nuts, lean meats, fish and even cereals.

None recommended: Instead, a well rounded and nutritious diet, in conjuction with a robust resistance exercise plan, is generally the medically recommended method for healthy muscle gain. Supplements are not FDA regulated and thus not rigorously tested for safety and efficacy.