Both Kathy and Nicky Hilton Are Obsessed with This Face Serum — and It's Under $25!

Nicky Hilton and her mom Kathy Hilton are both huge fans of skincare — and surprisingly, the one that's at the top of their rotation now is from the drugstore.

"I've been using No.7 Lift & Luminate serum," Nicky, 40, says of her go-to from the beloved British skincare brand.

"It's so funny, because my longtime facialist, who I've been going to forever, recently told me my skin had changed," Nicky shares, adding, "She told me, 'Your skin tone has evened out a lot. What are you using that's different?' And I told her about the Lift & Luminate. I've noticed a difference after just seven, eight weeks."

Kathy, 65, who also uses the product — which costs around $33 — agrees with her daughter.

"It really is beautiful," she tells PEOPLE. "I have kind of blotchy skin sometimes and very sensitive and lighter skin than Nicky. And I find that it really has helped me do with even up my skin tone, which is great. If I'm not doing anything, I don't put makeup on. I go during the day just with my sunblock and serum, and then whatever cream it would be. I like the The Lift & Luminate Day Cream too."

Kathy adds, "It's a beautiful product. And I get a lot of things sent to me, but my own mom used to use No. 7 when we'd go to London. I can remember way back when — she'd load up on it."

Nicky adds she's always been obsessed with skincare, something that came from her mom.

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"Always," she says. "My mom introduced me at a very young age the importance of taking care of your skin and taking your makeup off every night and staying out of the sun. And I started with eye creams and night creams at like 16, 17 years old because she was like, you're never too young to start."

Kathy says that wisdom trickled down from her own mother.

"I was never the girl that wanted to lay out in the sun," she says. "All my friends would take the metal reflectors, put baby oil on and bake. But I'm too ADD to sit it around and sit in the sun. I just don't like it. So I always taught my girls that too. Of course they'd do their little spray tans or whatever, but no sun if at all possible."

Nicky interjects, "I've never done a spray tan in my life, mom!" she says with a laugh. "Though I did use the tanning beds more than I'd like to admit."

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As for her daughters, Lily-Grace, 6, and Teddy, 5, she says they're too little to care about beauty, but Kathy says they do like to watch their mom and grandma get ready to go out.

"They watch us getting ready," says Kathy. "Nicky and I work a lot together. So when she's coming out to L.A. and we're working or whatever it is, or it's somebody's birthday, they will see us glamming together. It is just very cute. Teddy, the little one, recently went, I want some toenail polish!'"