Men's silk pajamas: what science knows about the fabric we sleep in

In brief. A systematic review published in 2024 in the Journal of Sleep Research examined nine studies on the fabric we sleep in. It draws one clear conclusion—the fiber is not neutral, and its effect depends on the bedroom temperature—and one point rarely mentioned elsewhere: silk was not tested. Here is what I take from it, and how I am arranging my nights now that bedrooms are dropping below twenty degrees again.

What the research actually measured

Xinzhu Li, Mark Halaki and Chin Moi Chow searched six scientific databases and selected nine studies comparing sleep quality according to the fibers used in nightwear and bedding (Li, Halaki & Chow, Journal of Sleep Research, 2024 — doi:10.1111/jsr.14217).

Three findings stand out:

• a wool nightwear garment was associated with faster sleep onset in adults in cool conditions, and in older adults in warm conditions;
• linen sheets were associated with better sleep quality in warm conditions among young adults;
• a goose-down duvet was associated with more deep slow-wave sleep in cool conditions.

The authors remain cautious, and we should be too: the protocols differ too much from one study to another to draw up a ranking. They also call for standardized methodologies, using the same fiber samples, across comparable populations and temperatures. Nine studies is not many.

And since we're being frank: silk does not appear in these comparisons. So I am not going to tell you that it would perform better than wool—no one has measured that properly. What the review establishes does, however, apply to all fibers, including silk: the fabric you sleep in has an effect, especially when the ambient temperature changes. That's useful information, and it is enough to guide a purchase.

Why the question arises in late September

It comes now because the bedroom has just changed its pattern. We used to sleep at twenty-one or twenty-two degrees; now we often sleep between seventeen and nineteen, with the window ajar and the heating not yet turned back on. Yet to fall asleep, the body needs to release a little heat. Too many layers, and you sweat, then wake up at three in the morning. Not enough, and it takes an hour to get to sleep.

This is the season when men who slept shirtless all summer get dressed again at night. And therefore the moment when the choice of fabric stops being a decorative detail.

A matching pajama set isn't mandatory - the trio is

I have never owned a matching two-piece pajama set, and I have no use for one. What works for me is a trio of separates: a layer close to the body, a top, and a bottom. Each addresses a distinct problem, and you can adopt just one.

The top, the piece I would start with

This is the piece that makes the quickest difference. Shoulders and arms spend the night partly outside the duvet: they are the ones exposed to the cold of the room and that start warming up again as soon as you pull the sheet back over yourself. A 100% mulberry silk long-sleeved T-shirt works precisely there - a close weave, a close-to-the-body drape, and thirteen shades from Deep Black to Ivory White, from S to XXXL. It has one understated advantage: it can also be worn under a shirt during the day, making it the least specialized piece of the set.

The bottom

This is the most personal piece. Some people can't stand wearing anything under the duvet, while others get cold legs as soon as the thermostat drops. If you're in the second group, look for fluidity rather than thickness: the jacquard silk trousers keep the legs covered without constricting them, and the pattern woven into the fabric does not wear away like a print.

The layer closest to the body

The least visible, the most everyday. The mulberry silk boxer briefs are grade 6A, 19 momme, available from L to 6XL, and the silk underwear offers a roomier cut. In my experience, it's also the piece that wins people over: you try it for one night out of curiosity, and never go back.

Momme, in three lines

Momme measures the weight of silk. Below 16, the fabric becomes transparent and fragile; around 19, it strikes a balance between structure and fluidity - the standard for garments. Above 22, it becomes more opaque and durable, but loses a little lightness. If you're interested, everything is explained in detail in our momme guide.

Care, without the mystery

• Hand-wash in cold water, or use a delicate machine cycle in a mesh bag.
• Gentle detergent, without enzymes or bleaching agents.
• Don't wring it: press the garment between two towels.
• Lay flat to dry, in the shade, never on a radiator.
• Iron at a low temperature on the reverse side, if really necessary.

Allow three minutes a week. That's the only real price of silk.

What I don't promise

No fabric will make a man sleep if he goes to bed at two in the morning with his phone. Silk is not a treatment, and I won't attribute any medical benefits to it. What a good fabric can do, however, is concrete: remove two nighttime irritants, moisture and friction. When you wake up three times a night, removing two of them matters.

If you're completely new to the fabric, I've written elsewhere where to start with men's silk — it's the prerequisite for this article.

Frequently asked questions

Is silk really better than cotton for sleeping?

No serious study has directly compared the two for sleep quality. The 2024 review shows that the fiber matters, without testing silk. What we can honestly say: silk wicks moisture well and glides over the skin, addressing the two most commonly cited nighttime discomforts.

Should you buy a matching silk pajama set?

No. Three separates cover the same needs with more flexibility, and you can adopt just one to start.

Which momme weight should you choose for men's sleepwear?

19 momme is the balance point for a garment: enough structure, enough fluidity. Below 16, the fabric wears out faster.

Is silk warm enough for autumn?

Worn alone in a seventeen-degree room, a fine silk piece won't be enough for everyone. It works well as a thin layer under the duvet, or layered. It's a fabric that regulates, not one that insulates.

Can silk be machine-washed?

Yes, on a delicate, cold cycle, in a mesh bag and with a gentle detergent. Laying it flat to dry matters more than the wash cycle.

Where to start

If you were to test just one thing this autumn, choose the top: it's the piece that gets noticed most quickly, at night as well as under a shirt. The rest may or may not follow, and that's fine. All the pieces are gathered in the Men's collection.

— Malik, for the StudioSoie Journal