Scarlett Johansson, one of the most photographed and filmed women in the world, has worn caked-on makeup since her screen debut at age nine. No wonder she collaborated with Kate Foster to launch a skin-care brand, called the Outset. All of its serums, cleansers, moisturizers, and masks are vegan, fragrance-free, and re-fillable. Though the Outset only launched last year, its popularity has propelled it to retailers such as Sephora, Goop, and HeyDay. As it turns out, Johansson’s night’s sleep is just as carefully calibrated. —Jensen Davis

When do you go to bed?
If it’s a Saturday, I try to stay up to watch [Saturday Night Live’s] Weekend Update. During the week, I try to go to bed by 11:30 because I get up really early to take my daughter to the bus in the morning.

Do you watch anything while getting ready to go to bed?
If I’m home with Colin [Jost, Johansson’s husband], we usually watch a show—right now we’re watching The Last of Us—or we watch a movie or catch up on a documentary. If I’m alone, I like to watch Dateline and get properly riddled with anxiety just before bed.

Do you take any supplements?
I’ve been taking magnesium, which I think helps me sleep more soundly. I used to use a [magnesium] spray that you put on the bottom of your feet, but it dries your skin out.

What’s one thing you have to do before bed?
I shower at night before I go to bed, and I shower in the morning too. I don’t always wash my hair at night—I always rinse. I have to be clean when I go to bed.

My husband will just fall into bed. He’s a comedy writer on a late-night show. He gets home at three a.m. and melts into bed—he can barely take his contacts out. I will wake up when he gets home and say to him, “Did you change? Is that the shirt you wore all day? I’m just saying … take your shirt off.” I’m like, you got in a cab, you were on the train with that shirt. I’d rather he sleep in no shirt. Just get that thing out of the bed.

take us through your skin-care routine.
I’ve been wearing makeup for work since I was a child, and so I got into the habit of always having a clean face before bed, even if I went out with friends and stayed out until four in the morning drinking margaritas.

I really only use the Outset products to wash and moisturize my face. Depending on how dry my face is, sometimes I give my skin a break from using night cream … sometimes I’ll just use our boosting oil. I also test out a lot of our products. I have things that are in the pipeline for us, or some things that we never ended up [selling] that I still love … I’ll be scraping up the remnants of some old products that we were testing out. I have a lot of pots of things that nobody will ever see.

I use the [Purifying Blue Clay] mask at night sometimes if I’m in the bath or reading. I got sent a whole bunch of Goop products, because the Outset is now available on Goop, and they have a soaking bath that’s oat and magnesium. I like that a lot. I like oats for skin softening. New York water is so hard here that you need to add oil or some kind of moisturizing component to a bath—otherwise your skin is so tight when you come out.

Scarlett Johansson’s bedtime routine involves rigorous product testing for her new skin-care line, the Outset.

How long does it take you to fall asleep?
I fall asleep really easily—I never had any problem falling asleep. As I’ve gotten older, I have a harder time staying asleep. I have a white-noise machine. My mom always had one when I was growing up. Now that’s a popular thing. I guess my mom was ahead of the curve.

When I’m winding down, I’ll put on my white-noise machine and close the blinds. I like to sleep in a cold, dark, quiet room. My husband probably thinks it’s like a crypt.

How does your husband feel about that?
I have blackout shades that no ounce of light can permeate. My poor husband, when I met him, he slept with no blinds. He likes to wake up with the daylight, no air-conditioning, just a fan. He doesn’t need any kind of noise machine. I have all these stipulations to sleep, and I can’t sleep without them. I guess I’m more neurotic in that way. He’s had to make a lot of adjustments.

I’ve gotten a little bit less neurotic about the light as I’ve gotten older, but my worst nightmare is staying out and seeing the sun come up.

do your children impact your sleep?
That’s the other thing: we have a baby monitor. My daughter [who is eight] wakes me up in a manner from a horror movie, one where you wake up and a small child is standing over you, staring at you. Or she likes to touch my forehead strangely. Then we have a [one-year-old] baby, and he does wake up a lot sometimes. But theoretically, I set myself up in the hopes of having a restful night.

Are you particular about your mattress?
Yeah, as you can probably imagine. I thought I liked a firm mattress. I used to have a Tempur-Pedic, but it was too hot. I found it to be not a good product. So I went to get a new mattress, and the woman said to me, “You need a softer mattress, because you’re petite. If you have a small frame you shouldn’t sleep on a hard mattress, because it puts a lot of pressure on your bones and your body.” So I bought a softer mattress. I don’t know why I let someone else tell me what kind of mattress I liked, but it sounded, in theory, like it was a good idea. I slept on a soft mattress for a couple of years, and I woke up every morning with so much back pain, with everything out of whack. Finally one day I just said to Colin, “I’m getting rid of this mattress! I can’t take it anymore!”

What about sheets and pillows?
I’m a crispy-sheet person. I have a feather allergy. What’s good is foam pillows where the foam is shredded. Those have a similar feeling to a down pillow, but they’re hypoallergenic.

Pajamas: yes or no?
I don’t like sleeping naked—that’s not comfortable. Usually I end up in underwear and a top. I don’t always like to wear whole pajamas to bed because I feel like I get twisted up. I always like the pajamas from the Gap. They’re just easy and cute and comfortable. And I like Eberjey. I’ve always liked the look of a nightgown, but I can’t sleep in it. I get too twisted up.

Where is your all-time favorite place to sleep?
One of my favorite situations to sleep in is when you go to work on set, and let’s say you’re shooting outside and you can’t shoot because it’s raining, so you have to take a break. It slows the production down, but everybody who has been working 16-hour days is like,’Oh, good. Now I can take a minute to relax in between strenuous work.’ There’s nothing better than lying in your trailer on the couch. You woke up at 5:30 in the morning, and now you have this unforeseen work break. You hear the pitter-patter of the rain falling on your trailer. You just fall into this midday coma on your couch.

The Outset is available online

Jensen Davis is the Junior Editor for Air Mail