Is it bad to sleep on your right side? Snopes consults with three medical professionals after an online ad “warns” people not to do so.

We showed Winter the ad, the Money Cougar article, and the CNN story. By email, he reiterated the information from the CNN story and referred to sleeping on the left side instead of the right as nothing more than a “tip.”

He said: “This ‘tip’ stems from the fact that if you look at a diagram of typical human circulation, venous blood returns to the heart via the left-sided vena cava system, so sleeping on your right side theoretically could impede that return flow. This is most often cited with pregnant women as that extra weight could be a small issue. I sleep on my left side all of the time!”