Always ask yourself if the treatment comparisons included only people (or animals) that are very different from you.
Animals are different from people in many ways. Most of the time when there are comparisons of interventions only in animals, it is very uncertain what the effects of the treatments are in people.
Other times, there are only intervention comparisons in people that are very different from you. For example, some interventions work differently in children than in adults and there may only be comparisons in adults.
REMEMBER: Ask whether you are very different from the people in fair comparisons of treatments, and look out for animal studies.