“Ask your doctor” are how all those TV ads for prescription medications go, along with the required scary warnings that in rare cases, your head may suddenly explode. Well, one patient who asked his doctor is President Donald Trump, who “heard a lot of good stories” how hydroxychloroquine and zinc could ward off coronavirus.

The way Trump told it Monday, the White House physician said OK and wrote the prescription for him to take the pill daily. A week and a half later, so far, so good, says the huckster who calls himself president.

We trust the White House doc would only prescribe a drug he believes to be in the best interest of his patient. We pray there was no undue pressure from a man who’s called the drug a “game changer” as contrary evidence has mounted, including FDA warnings that it presents serious risks to the human heart.

By touting the pill to millions, Trump now encourages countless people to besiege their doctors with pleas for their own prescriptions, leaving lupus and rheumatoid arthritis patients who truly need the now-scarce drug high and dry. Bad medicine indeed.

A far better use of Trump’s time would’ve been showing the world how easy it is to get a COVID test. New York Gov. Andrew Cuomo did his nose test on TV. Monday, he reported back negative.

Trump says that he doesn’t like the nose test. Instead, he’s thumbing his nose at the experts again — with potentially fateful results.