I agree! Placebo trials are important because we need a result that is not going to change. With this result we can then compare the other results to it to see if the other factor is useful. I do not see a problem with having a placebo trial I think they are very useful. I do not see anything wrong with it, I do not think it is unethical. It is needed to make sure we get accurate results with no bias. To have no bias they need to not know what they are given. I think they are necessary because they help show you the effects of the other factor since the placebo is basically the baseline.