Actress Mackenzie Phillips has joined the NOH8 Campaign, the silent protest which raises awareness and funds for gay rights causes, including ending California's 2008 voter-approved gay marriage ban, Proposition 8.

The 52-year-old Phillips is best known for playing Julie Cooper Horvath opposite Bonnie Franklin and Valerie Bertinelli in the long-running CBS situation comedy One Day at a Time. She also played Carol Morrison in writer-director George Lucas' 1973 coming of age film American Graffiti. In 2010, Phillips went public with her lifetime struggle with drug abuse during a guest spot on VH1's Celebrity Rehab with Dr. Drew.

The NOH8 Campaign is helmed by photographer-activist Adam Bouska and his partner Jeff Parshley. The pair photograph celebrities and everyday folks with their mouths duct taped and the campaign's familiar “NOH8” slogan often written on one cheek.

In her photograph, Phillips is wearing an unbuttoned white shirt – revealing a white tank top underneath – while holding her hands up in the air.

The campaign has also recently been joined by actress Shay Mitchell – who plays a gay teen on ABC Family's Pretty Little Liars – Hole frontwoman Courtney Love, country music singer LeAnn Rimes, actress-singer Miley Cyrus and actress Lindsay Lohan.