Jenner's photo was put on the cover of a gossip magazine, which had retouched it by putting makeup on the 65-year-old reality star's face.
Jenner sparked rumours of a sex change post his split from Kris as he was spotted with nail paint, long hair and earrings.
On his daily YouTube show 'The Trews', Brand, 39, said the constant media attention on Jenner's physical appearance is a form of bullying, reported People magazine.
"Transphobia seems to be the most recent and encouraged form of prejudice, now that racism and homophobia are not tolerated," Brand said.
Brand said people should sensitize themselves instead of resorting to bullying.
"This is bullying. Stop. Stop. Bruce Jenner is a human being. If you want to learn more about transgender issues, look at GLAAD.Org," he said.