Lena Dunham feels "more productive" in a bathing suit than "full hair and makeup".

The 35-year-old actress shared a revealing picture of her bottom in a coral swimsuit alongside a snap of herself all glammed up for a Sundance Film Festival press junket for her upcoming movie 'Sharp Stick'.

She wrote alongside the two photos: "You'd be surprised to know that I am being way more productive in the bathing suit booty pic than in full hair and makeup (hunkered down, trying to bring the people what they don't yet know they want!)"

For the junket, the 'Girls' creator wore a Tyler McGillivary floral mini dress, while John D did her hair and Toby Fleischman handled her makeup.

Meanwhile, last year Lena fired back at body-shamers after reading "gnarly" comments online following her wedding with Luis Felber.

She received a wave of congratulatory messages, but her joy had been tarnished by the cruel remarks made by some people, which reminded her of why she's deliberately taken a step back from social media in recent times.

She reflected: "This past week was lovely for so many reasons...

"I say this because over the years, I've shared many challenges with you and these moments of joy had me thinking that we should admit when we’re happy too- it's not a crime.

"But all of this safety made me forget, for a moment, why I’ve created such intense boundaries with the internet over the past few years.

"It's a little too easy to feel the glow of support and forget about the cesspool lurking behind it- so I took a peek, and saw some gnarly s***, most not worth responding to or even sharing with you."