From who "didn't really like each other" in the cast to it being "clear that Katie was the star," here are Philipps' biggest revelations.
The memoir -- about her childhood, start in the business on "Freaks and Geeks" and her career and personal life since -- dropped this week, and it's filled with some intel from her WB days.
Philipps wasn't one of the OG stars of the teen drama, coming onto the show when the residents of Capeside moved to college in Season 5. From day one, it wasn't an easy adjustment for her, starting with how she was treated by both the wardrobe and makeup departments.
"Wardrobe was really disheartening. The woman looked at my body skeptically," she explained in the book. "'Hmmm. I think the trick with you will be to just accentuate your chest and push up your boobs and maybe show your legs, and then just try to hide from here' — she pointed to right under my boobs — 'to here' — she pointed to right above my knees."
"I was confused. There needed to be a trick? My body was a problem? I hadn't realized that yet," Philipps continued. "I just assumed because I'd gotten the part, they wanted me the way I was. I didn't know there were parts of me that should remain hidden."
When it came time to deal with makeup, they wanted to cover up all her moles. "I guess the network and producers don't like all these moles on you, so we're supposed to cover them up. Although I've never had to do that, and it seems insane," the makeup artist allegedly told her.
Her struggle with wardrobe didn't go away, as she was constantly compared to star Katie Holmes throughout her time on the show.
"I settled into weekly wardrobe humiliations, where I was tucked and pulled and my body looked at with such disdain by the woman doing the costumes, all while she would talk about how Katie can just WEAR ANYTHING, you know," Philipps wrote. "Because she just WORKS SO HARD at it. She LOVES running and SPIN CLASS! I knew it was pointed."
According to Philipps, "it was clear that Katie was the star" of the show on set. She even recalled one moment where Busy totally blew a monologue, only to have the director tell her, "Listen, yeah, that was terrible but don't worry if you can't get it. We'll just cut to Katie. That's what we mostly do anyway, because ... I mean. Look at that face!"
Philipps added that Holmes herself was always "very sweet" to her, but she still "had a hard time really connecting with her." Michelle Williams, however, she bonded with right off the bat and it's a friendship that lasts to this day.
In general, however, the vibe on set wasn't exactly one filled with camaraderie.
"With 'Dawson's,' it was immediately clear to me that I wasn't walking into a situation like we had on 'Freaks and Geeks,' where everyone hung out all the time," said Philipps. "Maybe that was how it had been when the show first started, but by the fifth season, when I showed up, the main cast didn't really hang out together that much and they obviously had some fairly intense dynamics going on."
"It was clear that Joshua Jackson and James [Van Der Beek] didn't really like each other, and while Katie and Michelle were friendly, it didn't seem like they were very close," she continued. "Kerr Smith was sort of friendly with everyone."
She added that Jackson was "a good guy and just wanted to be well-liked," but wished she had "known the term 'mansplaining'" when she met him. "His ability to turn a conversation into a dissertation was incredible."
Philipps also recalled a time she had a sex scene with Jackson and he brought his then-girlfriend to set. Noting that she wasn't ever "really comfortable" with sex scenes in general, Philipps said having her around didn't make it any easier.
"Having the other actor's girlfriend there, watching me and making weird comments after each take, like how she was going to need him to Listerine his mouth before she kissed him again, was just too humiliating," she wrote. "I felt like shit."
Another moment that caught her by surprise happened while filming a scene with Van Der Beek for a Thanksgiving episode.
"See? You got lucky. Your show was canceled after the first season," she said he told her. "I was so shocked by his complete lack of perspective, I was speechless. I mean. YOU ALL are the lucky ones, here on SEASON FIVE of your HIT TV SHOW. Your LIVES were changed."
Philipps would appear in both the fifth and sixth seasons of the show, but was completely MIA in the two-part season finale, which Kevin Williamson returned to write.
"When the writers turn your character into an alcoholic for your second season, it will hurt your feelings, but you'll get over it.," Philipps recalled. "And when they don't write you into the finale, it will hurt your feelings, but you'll get over that too. Because you understand they probably would have just cut to Katie anyway."
Philipps' book, "This Will Only Hurt a Little," is out now.