The chemicals in bitter melons are powerful health tools, but should be respected as well. Pregnant women should not consume bitter melon, because it can stimulate excess menstrual bleeding, and more research must still be done on consuming bitter melon while breast-feeding, so for now, it is best to avoid it. Also, as mentioned earlier, it acts very strongly to reduce blood sugar levels, which can become dangerous, particularly in the time leading up to and after surgical procedures.
Finally, some people are particularly sensitive to dehydrogenase deficiency, which bitter melon can cause. The symptoms of this are similar to anemia, and also include headaches, fevers, and stomach pains. This is a very powerful fruit, and it is highly recommended that you speak with your doctor or physician before adding it to your diet.