“I do have days where I feel ugly. I woke up one day and I had two huge pimples on my face; it was right before I was about to film a movie in Atlanta [soccer drama “High Expectations”]. It was so embarrassing because it was huge and I could not cover it up,” she told Page Six Style.

“I definitely have my moments where I don’t feel pretty, for whatever reason. But then I have the other days when you just feel better. That’s what life is; it’s full of ups and downs.”

The “Baby I’m Coming Home” singer, 27, credits her mother with many of her beauty secrets.

“Even before Fifth Harmony, my mom really taught me to take care of my skin. Wash morning and night. Do a scrub twice a week. Never, ever sleep with your makeup on,” she shared. “I’ve also learned how important it is to stay hydrated. I have seven bottles of water each day. It literally changes everything, because the number-one thing I found is that when you stay hydrated, your energy level just changes. Like, that can be my coffee.”

As for her skincare essentials? “I’m cheap and bougie, so I use Cetaphil from the drugstore and then I use La Mer Moisturizing Soft Cream ($190),” Brooke said. “I also use St. Ives Apricot Scrub ($3.89) twice a week; I love that. It is super simple and it helps my skin.”

The musician names Davines OI All In One Milk ($35) as her holy grail hair product. “It is a leave-in conditioner and detangler; I’m obsessed with it,” she said. “It’ll get even the toughest tangle out.”

And Brooke should know, having struggled with serious hair damage from her time in the girl group. “When I was super bleach-blonde, it was breaking,” the naturally brunette star said.

“At one point I had alopecia, but it was from all the stress that was going on. My hair was fried, so I decided to lay off on the bleaching and let it grow out, and that helped so much. I didn’t go as blond again. I went more like a honey blond, and that helped tremendously — and using heat protectant.”

“Thank god I stopped bleaching it,” she added. “My hair is in a much better place.”

Brooke’s memoir “Finding Your Harmony” is out now.