Robert Downey Jr. and Jimmy Fallon are terrible medicine salesmen in even worse wigs

"If your erection lasts more than four hours, that has nothing to do with Zynerma. But congratulations."

On Wednesday's episode of The Tonight Show starring Jimmy Fallon, incumbent Dr. Dolittle Robert Downey Jr. joined the host to make an ad for a fake allergy medicine. And thank goodness it isn't real. Zynerma sounds like a truly terrible product, carrying side effects such as "slacks, premature fatherhood" and "hat failure."

Dressed like religious cult members with Tribbles atop their heads, Downey and Fallon each took turns reading their lines off cue cards — lines they apparently hadn't seen before filming.

"Zynerma shouldn't replace your asthma inhaler, and it can't replace her," said Downey, trailing off sadly. "Sorry big guy, but she's not coming back."