When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. A cancer diagnosis is so difficult. It felt very devastating when Dave called. Dave and [his wife] Melissa called and let us know personally before it went out to the press.

The "Full House" alum revealed Thursday that he wasn't able to shave his head because he's filming a new project soon — and said the criticism "really hurt me."

John Stamos is facing backlash on social media for wearing a bald cap to support his “Full House” co-star Dave Coulier who shaved his head amid his stage 3 cancer battle. Stamos, 61, shared three Instagram photos Monday that featured him wearing his bald cap as he spent time with Coulier, 65.

I’m embarrassed for people that they waste time on this," Stamos said of the backlash. "All I was doing was cheering up a friend."

Dave Coulier and John Stamos have a long history. The two spent years filming the beloved series Full House together, but their friendship did not end there. After the 65-year-old revealed he was diagnosed with stage 3 Non-Hodgkin lymphoma,

Earlier this month, the Full House actor - known for playing Joey Gladstone on the sitcom, revealed he had been diagnosed with a "very aggressive" form of non-Hodgkin lymphoma and was undergoing chemotherapy treatments.