Hailey Baldwin Reveals the Hands-Down Sexiest Thing Justin Bieber Does

If you keep up with the rotating news cycle or fan accounts on Instagram, you've probably noticed Baldwin is always photographed with her hair slicked back in a bun. "I hate the length of my hair when it's down," she explained, motioning to her chin where her natural hair length hits. "If I want to wear it down and actually like it, I'll put extensions in it."

She added, "When I was 16, my hair was really long, and then when I started modeling I was like, I have to do something cool or trendy. So I chopped it all off, and ever since I chopped it off, I've never been able to grow it back. Part of that is because I've never been patient enough to let it grow — it takes forever."

Because you can't live your life in a ponytail (or can you?), Baldwin is doing everything she can to grow her hair out. "I'm taking all the supplements," she said. "Jen Atkin makes the Ouai Hair Thinning Hair Supplements ($28); I'm taking those and I'm taking Viviscal. I'm really trying!" (It's worth noting that she has tried prenatal vitamins, thank you for asking, but had a — let's say nauseating — experience after taking one on an empty stomach: "It scarred me — I feel like I can never take that again.")

And while it might not be giving Baldwin the length she craves, the additional boost of vitamins is helping her nails. "Mine used to be so weak because I would put acrylics on them and then pick them off in the shower and it would rip layers off. They're nice now because I let them breathe."

In a word: smell good. "A guy's scent is so important," she said. "That smell — it's what makes you miss them when you're away from them. I honestly don't know what my fiancé wears, but whatever it is, it's working." (Clearly.)

While that newly engaged glow is definitely the cousin-twice-removed of pregnancy glow, you can't give Bieber all the credit for Baldwin's lit-from-within skin — she does a lot of work to keep it that way. "I'm crazy about skin care," she said. "When I'm traveling, I'm always moisturizing, drinking lots of water. I use all of [dermatologist] Barbara Sturm's products. Her masks, her Face Cream ($215), her glow serum — they are amazing, and she also the nicest human being."

Her favorite in the lineup? Dr. Sturm's MC1 Blood Moisturizer, which goes for around $1,400 a pop and requires an in-person appointment so she can draw your blood, extract the plasma, and infuse it in the cream. "I love that weird blood cream." Baldwin laughed. "It is fascinating to me, and it works. I'm a nerd about the science of skin care and health, so for me, I'm like, 'This is so cool!'"

When she's not walking the runway at New York Fashion Week or shooting a high-profile campaign with Adidas, Baldwin likes to keep it relatively low-key. "I wear as minimal makeup as I can on my days off, because I'm always getting harsh, heavy makeup put on my skin," she said. "I'm not big on foundation. That's also why I like the BareMinerals products; they are really light and made with great ingredients, so it's not hard on your skin. If I'm doing my everyday makeup, I always use the Barepro Glow Highlighters ($28) and maybe a little concealer."

"Kylie and her sisters all have these huge, cool glam rooms — it's like a candy store for makeup," Baldwin said. "I might need to think about [installing] one now that I'm going to own a house, or maybe I'll see if I can get a little glam closet. I would definitely ask Kylie for a few tips."

Sometimes, feeling sexy is all in the details: "I like a bold red lip — that's just really sexy to me," she said. "You can do just mascara and a bold lip and that's it, and it looks really nice. I'm always experimenting with different brands, and I've been loving the BareMinerals Statement Luxe-Shine Lipsticks ($20). The texture of those are really creamy and not dry at all."

"Both of my parents have really nice skin," she said, referring to actor/producer Stephen and artist Kennya Baldwin. "They both weirdly look a lot younger than they are. I have to say, good genetics — thank you, God. Here's what I will say about my dad. He's an actor, so he's used to having makeup put on at like movie sets. As a kid, I remember I'd catch him putting on some powder when we had to walk on red carpets, and I'd be like, 'Oh, hello, what's happening here?' [Laughs.] He would be like, 'I don't want to look shiny!'"