During the presidential debates and primaries, commercials have appeared for Neulasta, an injected drug used for some cancer patients undergoing chemotherapy to help the immune system rebound faster. The ad featured two loving sisters, one of whom has cancer, enjoying a seafood meal near a beach. It urged viewers to “ask your doctor about Neulasta.”

Neulasta costs about $5,000 per injection in the United States, and generated $4.6 billion in sales in 2014 for its maker, Amgen. But why the need to promote it? While Neulasta is more or less standard after certain types of chemotherapy, it is discretionary for others, but if a patient asks, the doctor is more likely to prescribe it. More important, perhaps, several generic versions of the drug that will be much cheaper are nearing approval, so Amgen wants patients to request their brand.

Worried patients are, of course, a great captive audience. Television coverage during the debates and primaries has featured many commercials for new drugs to treat Type 2 diabetes, a condition that is often associated with the overweight and is most common in middle age and beyond. Ads for the condition have increased 200 percent in the last three years, Nielsen found. Even though older, cheaper drugs for Type 2 diabetes are effective for most people — and, doctors say, should generally be the first line of treatment — the ads have promoted an array of new injections and pills, including Tuojeo, Farxiga and Victoza (each of which costs between $500 and $700 per month).

During the 1980s and ’90s, the Food and Drug Administration set some rules for medical advertising — then in its infancy — to ensure that patients got accurate, balanced information. Current regulations mandate that manufacturers advertise their drugs only for the disease for which they received federal approval, and that they list all potential side effects and risks.

Yet clever marketing departments have danced around those limits. Some drug ads, for example, feature emotional patients telling their success stories, followed at the very end by a rapid-fire litany of all the things that could go wrong. Others are called “help-seeking ads,” in which a specific drug isn’t named (so that its side effects don’t have to be mentioned) but just enough information is provided about the condition, including a website for advice, to guide you to the branded medicine.

Both types of commercials were on display during this year’s Super Bowl, an event traditionally associated with ads for beer and cars. One featured a cute pink coiled human intestine with a face and legs running to the toilet thanks to a condition called irritable bowel syndrome, which can cause diarrhea. That ad recommended a pill called Xifaxin, which costs about $1,850 per month, although gastroenterologists frequently prescribe dietary changes, stress management and over-the-counter pills.

Another ad promoted Jublia, a new topical drug for toenail fungus that costs thousands of dollars for a full course of treatment. Complete cure rates in studies — under 20 percent after 48 weeks of use — aren’t mentioned in the ads.