The "Charlie's Angels" and "Something About Mary" star might look positively flawless when she's on the red carpet -- but she's no stranger to acne -- like really, really bad acne. In an except from her 2014 book "The Body Book: The Law of Hunger, the Science of Strength, and Other Ways to Love Your Body", published in Seventeen, Diaz outlined how this all affected her.

"You might think my life is always totally glam, but I used to have horrible acne -- deep, boiling pimples -- the kind that hurts so badly, I didn't want to leave my house," wrote Diaz. "My friends said they didn't notice, but I'd say, 'It's the only thing anyone can see!'" Diaz went on to say that no amount of foundation and concealer could mask her bumps well enough.

Luckily, Diaz explained that she believed her diet -- which consisted of burritos and cheeseburgers at the time -- was partially to blame for her skin. "Once I cut out the junk, I saw such a major difference that I felt like an idiot," she wrote. "It not only cleared up my acne, but it also gave me this huge amount of energy."

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Real talk: Mindy Kaling is one of the funniest women on the planet. And she's not afraid to post a pimple-ridden selfie online (bless her). In one Instagram post, she sports spot treatment on her face, writing in the caption, "That zit cream in your 30s life. At least I'm not going on "The Tonight Show" later today."

Kaling's acne-fighting secret? She shared it in her memoir, "Why Not Me?". Kaling wrote that she relies on a pretty damn high-tech device. "I bought this wand, the Tria Acne Clearing Blue Light, from my dermatologist's office," said Kaling in her book. "At one point I was spending so much time with the device that I started calling him Wall-E. He looks like a fancy sex toy from Japan. His job is to 'eliminate acne-causing bacteria deep beneath the skin's surface,' and I have to hold him pressed against my face for twenty minutes every night."

BTW: Kaling went on to say that "Wall-E" feels like a "tiny white-hot iron you are pressing against your already-sensitive pimple. It's hellish. But it's very effective at squashing and destroying pimples, so you don't care."

Image via @mindykaling

Katy Perry isn't shy -- and that goes for whether she's putting Taylor Swift on blast or talking about her skin issues. The "Swish, Swish" singer even used to be a Proactiv spokesperson. "You would think I would be the most confident person, but the most confident person still has their moments," Perry said in a commercial for the brand. "A lot of my insecure moments related to my face and to my skin problems." In the commercial, she points to her mouth, nothing that she had blemishes around it. "I wanted to hide," she said.

In an interview with Refinery29, Perry said that even though she no longer works with Proactiv, she still uses their products, citing their Skin Smoothing Exfoliator as one of her faves.

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"Royals" crooner Lorde might only be 20 years old, but she's wise beyond her years. In a Twitter post, she pointed out the difference between two photos of herself from the same day -- one had been touched up and one hadn't. "I find this curious -- two photos from the same day, one edited so my skin is perfect and one real. Remember flaws are ok :-)"

She also snapped a pic of herself treating her skin and shared it with her 5.7 million Instagram followers. "In bed in Paris with my acne cream on," she wrote in the caption.

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The "La La Land" actress told Refinery29 that she used Accutane, a powerful prescription acne med. "I'm actually pretty interested in skin care, because I had bad hormonal acne when I was 17, and they put me on Accutane for it," she said in the interview. After two months on the Accutane, I went off of it, and since then, my skin, my mouth, my lips, my eyes are all so dry."

Fun fact: After going off Accutane, Stone said she got stress acne -- and that it was airbrushed out of her breakout (see what we did there?) movie, "Easy A." "I realized how debilitating and embarrassing it can be to have cystic acne," she said. "So I'm really interested in the biology of what makes up acne and how to work on it from the outside, too."

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