Justin Bieber boasts a great head of hair and it's his crowning glory. But that shouldn't give him license to talk smack about other famous gentleman with lackluster locks. Nevertheless, the well-coiffed Biebs took a few pot shots at Prince William, the future King of England, for his famously (and fastly) thinning follicles. It's easy for the Biebs to drop a diss when he sits in the lofty position of having a fuller head of hair than the Prince.

"I mean, there are things to prevent that nowadays, like Propecia," Biebs told Rollacoaster mag (quotes via The Telegraph) about William's hair issues. The Biebs appears on the cover of said mag, boasting a thick, lush and enviable head of hair, therefore his commentary on someone else who is follicularly challenged feels a tad ill-advised.

"I don't know why he doesn't just get those things, those products," Bieber continued. "You just take Propecia and your hair grows back. Have you not got it over here?"

Biebs, Biebs, Biebs. What were you thinking making such comments? That was not very swaggy of you, bro!  It's not as easy as you make it sound. You don't just take meds and -poof- wake up with a new crop of hair. Walk a mile in William's shoes before you go spouting off like that.

Prince Bill is a handsome gent who scored a babe for a wife with Kate. He will be king one day. He can't help the genetics which have caused his hair to betray him. So ease up on the criticism. Because you never know. One day you may find out that you're not only the Hair Club for Men president, but also a client.

Watch the Justin Bieber 'As Long as You Love Me' Video