What's Really in Your Pajamas — and How to Sleep in Something Safer

I watched The Plastic Detox on Netflix in March and couldn't sleep after.

Not because it was sensationalized — it wasn't. Dr. Shanna Swan, one of the world's leading reproductive epidemiologists, follows six couples with unexplained infertility through 90 days of reducing their exposure to plastic-associated chemicals. The couples swapped synthetic clothing for natural fibers, cleared their kitchens and bathrooms of plastic, and changed their personal care products. Three of the six couples got pregnant after filming concluded. The rest saw measurable reductions in chemical load in their bodies within months.¹

What stayed with me wasn't the fertility angle specifically. It was one statistic Dr. Swan cited almost in passing: skin can absorb more than 60% of the chemicals it comes in contact with. And one of the first things the couples changed was what they were wearing to bed.

That's exactly why I started More Sunday.

The average person spends roughly one third of their entire life asleep — approximately 26 years, pressed against fabric, night after night, while your body does its most important work.² I kept asking myself: if we're going to be that intentional about what we put in our bodies, shouldn't we be equally intentional about what we put on them for eight hours every night?

This isn't a fear article. You cannot eliminate chemical exposure from modern life — that's simply not realistic. But you can make smarter choices about where your exposure is highest and reduce it there. Sleepwear, given the hours you spend in it and the state your body is in during sleep, is one of the most logical places to start.

Here's everything I wish I'd had in one place when I was first researching this.

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What Are Endocrine-Disrupting Chemicals — and Why Should You Care?

Endocrine-disrupting chemicals (EDCs) are substances that interfere with your body's hormone system. They can mimic hormones, block them, or alter how your body produces and responds to them.³

Your endocrine system regulates almost everything: sleep cycles, metabolism, reproductive health, thyroid function, stress response, immune response, and more. When EDCs interrupt that system — even in small amounts, and even at the wrong time — the downstream effects can be significant.

The World Health Organization and the National Institute of Environmental Health Sciences both list EDCs as a serious global health concern.⁴ Research has linked EDC exposure to disrupted sleep (including during menopause and perimenopause), reproductive issues, thyroid disorders, metabolic changes, and developmental effects in children.⁵

Here's the important nuance: EDCs are everywhere. They're in food packaging, cleaning products, personal care products, cookware, furniture, and yes — clothing and bedding. The goal isn't to panic about this. The goal is to understand where your exposure is highest and make practical reductions where it actually makes a difference.

Which brings us back to what you're sleeping in.

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What's Actually in Most Pajamas

Most sleepwear sold today is made from one of the following: polyester, nylon, a cotton-polyester blend, or treated cotton (wrinkle-resistant, moisture-wicking, or flame-retardant). Each category carries a different chemical profile.

Synthetic fabrics (polyester, nylon, acrylic)

Polyester and nylon are essentially plastic fibers. During manufacturing, they're treated with a range of chemicals — and the dyeing process for synthetics relies heavily on disperse azo dyes, which make up approximately 60–70% of all fabric colorants used in the textile industry.⁶

The problem with azo dyes on synthetic fabric is twofold. First, they have low molecular weight and a lipophilic (fat-loving) structure, which means they can penetrate the skin more readily than dyes on natural fibers.⁷ Second, some azo dyes break down via reductive cleavage to release aromatic amines — compounds that are classified as potential carcinogens and have been shown to be mutagenic and genotoxic in research settings.⁸ The majority of disperse azo dyes used in the textile industry are currently unregulated in the United States.

Synthetics also trap heat and moisture against the body — which matters because heat and sweat increase dermal absorption of chemical residues.⁹ When you wear polyester pajamas to bed, you're sleeping in a warm, moist microenvironment that can accelerate how quickly any residual chemicals move through your skin.

Other chemicals commonly found in synthetic fabrics include:

• Phthalates — plasticizers linked to hormonal disruption, particularly affecting estrogen and androgen pathways¹⁰
• Bisphenols (BPA and its substitutes) — used to improve flexibility and durability; linked to hormonal imbalances and reproductive concerns¹¹
• PFAS ("forever chemicals") — found in moisture-wicking, stain-resistant, and wrinkle-free finishes; linked to immune disruption, liver effects, and developmental concerns¹²

Treated cotton

Cotton in its natural state is one of the better fiber choices. The problems arise in processing. Conventional cotton is one of the most pesticide-intensive crops in the world, and those residues can persist into finished fabric. Beyond that, many cotton garments are treated with:

• Formaldehyde — applied to prevent wrinkles, improve stain resistance, and resist mildew. Formaldehyde is classified as a carcinogen by both the International Agency for Research on Cancer and the U.S. National Toxicology Program.¹³ It's commonly found in "wrinkle-resistant," "permanent press," and "easy care" garments.
• Flame retardants — especially in children's pajamas. Polybrominated diphenyl ethers (PBDEs) and other flame retardant chemicals are classified as endocrine disruptors and are persistent in human tissue.¹⁴
• Chlorine bleach and solvents — toxic by inhalation and skin contact; chlorobenzenes used in processing are among the more concerning residuals.¹⁵

Washing helps — it removes a significant portion of residual chemicals before first wear. But it doesn't eliminate everything, and some finishes are designed specifically to be wash-durable.

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The Absorption Reality: Why Sleepwear Is Different From Daywear

You might be thinking: I wear clothes all day and I'm fine. Why does sleepwear specifically matter?

A few reasons.

Duration of contact. You wear pajamas for 7–9 hours continuously, in a state where your body is not moving, ventilating the fabric, or changing position as frequently as during the day.

Skin is thinner in certain areas. Breast tissue, the inner thighs, and the abdominal area have higher skin permeability than areas like palms or shins. These are exactly the areas in sustained contact with pajama fabric overnight.¹⁶

Heat and moisture increase absorption. Your body temperature shifts during sleep cycles, and natural sweating occurs even when you don't feel warm. Both heat and moisture open pores and accelerate the rate at which chemicals can move from fabric into the body.¹⁷ This is the same reason dermatologists pay attention to what's in the creams you apply at night — your skin is more permeable during sleep than during the day.

Your body is in repair mode. During sleep, your body is doing its most important hormonal work — releasing human growth hormone, regulating cortisol, producing melatonin, and running dozens of other hormonal processes. Introducing EDC exposure during this window is, at minimum, worth thinking about carefully.

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You Can't Eliminate This — But Here's How to Reduce It

Say it again for clarity: you cannot completely eliminate chemical exposure from your daily life. That's not a realistic goal and it's not what this article is suggesting. EDCs are in the air, the water, the food system, and the consumer products that make modern life functional.

What you can do is prioritize reductions where your exposure window is largest and your substitution options are best. Sleepwear is a high-leverage category because:

• The contact time is long — roughly one third of your life
• The skin areas involved are among the most permeable on your body
• Genuinely clean alternatives exist and are accessible
• It's a one-time decision that changes thousands of future nights

Practical steps, in order of impact:

1. Wash before first wear — always, for every new garment. This removes a significant portion of residual manufacturing chemicals, excess dyes, and surface treatments.¹⁸
2. Choose certified natural fibers for sleepwear — look for OEKO-TEX Standard 100 or GOTS certification (more on what these mean below)
3. Avoid "performance" finish labels on anything worn to sleep — wrinkle-resistant, moisture-wicking, permanent press, and stain-resistant labels signal chemical treatments
4. Replace your pillowcase first — your face is in contact with it for eight hours; it's the highest-priority single swap
5. Prioritize children's sleepwear — children's skin is thinner and more permeable; babies and young children spend more hours in fabric contact than adults

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What Certifications Actually Mean — and Which Ones to Look For

This is where most people get confused, because the label landscape is legitimately complicated. Here's a plain-English breakdown of the three you actually need to know.

OEKO-TEX Standard 100

OEKO-TEX Standard 100 is a product certification — it tests the finished textile against a list of over 100 harmful substances, including prohibited azo dyes, formaldehyde, nickel, phthalates, and pesticide residues. If a garment carries this label, it has been independently tested and verified to be free from those substances at levels that could harm human health.

What it is: Chemical safety verification of the finished product
What it covers: Any fiber — natural or synthetic
What it doesn't cover: How the fiber was grown, environmental practices, labor conditions
Best for: Verifying that what touches your skin has been independently tested and cleared

OEKO-TEX Standard 100 is the certification most directly relevant to skin safety and EDC reduction. It's what to look for first on sleepwear.

GOTS (Global Organic Textile Standard)

GOTS is a more comprehensive certification that covers the entire supply chain — from how the fiber was grown (must be organic) through processing, manufacturing, and social compliance. It restricts chemical inputs at every stage of production, not just in the finished product.

What it is: Full supply chain certification for organic natural fibers
What it covers: Cotton, linen, wool, hemp — organic natural fibers only
What it doesn't cover: Synthetic fibers or silk (silk is not classified as an organic fiber under GOTS criteria)
Best for: Organic cotton clothing and bedding where you want environmental and ethical assurance alongside chemical safety

MADE IN GREEN by OEKO-TEX

A newer, more comprehensive OEKO-TEX standard that combines chemical safety testing (Standard 100) with sustainable production verification and traceability. It's the OEKO-TEX equivalent of GOTS in scope — applicable to any fiber type, including synthetics and silk.

What it is: Combined chemical safety and sustainable production certification
What it covers: Any fiber type
Best for: When you want the highest level of assurance across both product safety and production practices

The quick guide

Certification	Tests finished product?	Covers supply chain?	Works for silk?	Works for synthetics?
OEKO-TEX Standard 100	Yes	No	Yes	Yes
GOTS	Yes	Yes	No	No
MADE IN GREEN	Yes	Yes	Yes	Yes

The bottom line: For sleepwear, OEKO-TEX Standard 100 is the minimum you should look for. GOTS is excellent for organic cotton products. Neither label is meaningless marketing — both require genuine third-party testing and carry publicly searchable certificate numbers.

Red flags to watch: "natural," "pure," "green," "clean," and "chemical-free" without a certification to back it up are unregulated terms with no legal definition.¹⁹ Any brand can use them. Certifications cannot be faked.

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Natural Fibers Worth Knowing

Not all natural fibers are equal, and "natural" alone doesn't mean safe — processing matters enormously. Here's a practical rundown.

Mulberry Silk

Silk is made from the cocoon of the Bombyx mori silkworm. In its raw state, it contains no synthetic additives. The fiber is composed of two proteins: fibroin (which gives silk its strength, luster, and structure) and sericin (a natural gum that surrounds the fiber and has been shown in research to improve skin elasticity and has natural antimicrobial resistance).²⁰

Silk fiber contains 18 amino acids — including glycine, alanine, and serine — that create a protein structure naturally compatible with human skin. These amino acids help skin retain moisture rather than stripping it, and the smooth surface of silk creates virtually no friction against skin or hair overnight.²¹

Silk is also naturally:

• Hypoallergenic — the fibroin protein structure resists dust mites, bacteria, and mold; dermatologists frequently recommend silk for patients with eczema, rosacea, and psoriasis²²
• Thermoregulating — the natural protein fiber responds to body temperature, wicking moisture when you're warm and retaining warmth when you're cool; particularly important for anyone dealing with night sweats or hormonal temperature fluctuations
• Breathable — unlike synthetic fibers, silk doesn't trap heat and moisture against the body, reducing the warm, moist microenvironment that accelerates chemical absorption
• Biodegradable — returns to the environment without leaving microplastic residue

A note on grade and weight: Silk is graded on a scale where 6A is the highest classification, indicating the longest, most uniform, most lustrous fibers with the least imperfection. Grade matters because lower-grade silk pills faster, loses its sheen after washing, and feels noticeably thinner.

Momme weight (the silk equivalent of thread count) tells you how dense and durable the weave is. More Sunday uses 19-momme — a deliberate choice. Heavier weights exist, but 19-momme hits the right balance: substantial enough to drape beautifully and last through years of washing, light enough to sleep comfortably in without overheating. It is genuinely a considered specification, not just a marketing number.

The dye process matters too — OEKO-TEX certified silk with chemical-free dyes is what you want for sleepwear, and the reason it's the non-negotiable standard at More Sunday.

Organic Cotton

Conventional cotton is grown with heavy pesticide use — the crop accounts for roughly 16% of global insecticide sales despite covering only 2.5% of agricultural land.²³ Organic cotton avoids synthetic pesticides and fertilizers, and when GOTS certified, the processing restrictions mean the finished fabric carries a genuinely lower chemical load than conventional cotton.

Cotton is not thermoregulating in the way silk is — it absorbs moisture and can stay damp, which can be uncomfortable for hot sleepers. But for people who run cool or prefer a more structured fabric feel, GOTS-certified organic cotton is a solid choice.

Linen (Organic)

Made from the flax plant, linen is naturally pest-resistant and requires less water and pesticide than cotton to grow. It's breathable, durable, and gets softer with washing. The texture is rougher than silk or cotton — some people love this, others find it too coarse for sleepwear. OEKO-TEX or GOTS certified linen is a good option for warm climates.

Wool (Merino)

Merino wool is genuinely thermoregulating and naturally fire-resistant without chemical treatment — which is why it's often used in children's sleepwear as a non-chemical alternative to flame retardant treatments. Fine merino is much softer than standard wool and suitable for sensitive skin. Look for OEKO-TEX certification to verify no harmful dyes or treatments were used in processing.

What to Be Careful With

Bamboo viscose/rayon — often marketed as natural and sustainable, but bamboo viscose is a chemically intensive process that converts bamboo pulp into fiber using solvents including carbon disulfide, which is toxic to the nervous system. The finished fabric is semi-synthetic, not natural. Look for lyocell or Tencel-process bamboo instead, which uses a closed-loop solvent system.²⁴

Modal — similar to bamboo viscose in its processing chemistry. Better than polyester but not a truly natural fiber.

"Silk-feel" or "silky" synthetics — polyester satin marketed as silky. This is a naming convention, not a fiber description. It is plastic. It has none of the protein properties, thermoregulation, amino acid composition, or skin benefits of real silk.

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Why I Started More Sunday

When I started researching what More Sunday should be made from, I expected to find a simple answer. What I found instead was a category full of products labeled "luxury silk" that were anything but — undisclosed grades, 6–8 momme weights dressed up in beautiful photography, and chemical dye processes that nobody was talking about.

The more I dug into the research on what we're actually wearing to bed — and what's in it — the more certain I became that this was worth doing properly. Not as a marketing angle, but as a genuine product commitment.

More Sunday was built around the specific properties that matter to someone who has thought carefully about this:

• 6A-grade 100% Mulberry Silk — the highest quality classification; the longest, most uniform fibers, the most lustrous and durable weave
• 19-momme weight — chosen specifically for sleepwear: substantial enough to last and drape beautifully, light enough to sleep in comfortably year-round
• OEKO-TEX Standard 100 certified — tested against over 100 harmful substances; independently verified, not self-declared
• Chemical-free dyes — no azo dye concerns; no hidden treatments
• 100% biodegradable — no synthetic fiber content; returns to the environment without leaving microplastic residue

Every piece in the More Sunday collection — the silk pajama sets, the silk robes, the silk pillowcases, the silk slip dress, the knit silk collection — is made to the same standard. Not because it's the easiest way to make a beautiful product, but because it's the right one.

The 26 years you spend sleeping are not a passive footnote to your health. They're when your body does its most important work. What touches your skin during those hours is worth getting right.

Explore the full More Sunday collection →

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Summary: The Practical Checklist

If you want to take meaningful action on reducing chemical exposure through sleepwear, here's the simplest version:

• ✓ Wash all new sleepwear before first wear — removes surface chemical residues
• ✓ Look for OEKO-TEX Standard 100 certification — the minimum standard for verified chemical safety in the finished fabric
• ✓ Choose natural fibers for sleepwear — silk, organic cotton, or fine merino wool
• ✓ Avoid "performance" finish labels on anything worn to sleep — wrinkle-resistant, moisture-wicking, permanent press, stain-resistant all signal chemical treatments
• ✓ Switch your pillowcase first — your face is in contact with it for 8 hours; the highest-priority single swap
• ✓ Prioritize children's sleepwear — thinner skin, more permeable, longer contact time
• ✓ Ignore unverified claims — "natural," "clean," "pure," and "green" without a certification number mean nothing legally
• ✓ Don't aim for perfection — aim for meaningful reduction in the highest-exposure category. Sleepwear is that category.

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Frequently Asked Questions

Is silk really better than cotton for reducing chemical exposure?

When both are certified — OEKO-TEX for silk, GOTS for organic cotton — they're comparable in terms of residual chemical safety in the finished fabric. Silk has additional advantages for sleepwear specifically: it doesn't trap heat and moisture the way cotton does, which reduces the absorption environment; its natural protein structure provides skin benefits cotton doesn't; and it's genuinely thermoregulating in a way that matters for sleep comfort. For most people, certified silk is the better sleepwear choice. Certified organic cotton is a strong all-purpose alternative if cost is a consideration.

Does washing remove all the chemicals from conventional pajamas?

No, but it helps significantly. Washing removes surface residues, excess dyes, and many chemical finishes before first wear. It does not remove chemicals that are chemically bonded to the fiber — formaldehyde in wrinkle-resistant finishes, for example, is specifically designed to be wash-durable. This is why certification matters more than washing alone.

Are flame retardants required in adult pajamas?

In the United States, adult sleepwear is not legally required to contain flame retardants. Children's sleepwear in sizes 0–14 is subject to federal flammability standards — but these can be met either by adding chemical flame retardants or by using naturally flame-resistant materials like wool, or by making tight-fitting pajamas that are less likely to catch fire. For children, look for "no flame retardants" labeling combined with natural fiber construction.

Is OEKO-TEX certification the same as organic?

No. OEKO-TEX Standard 100 tests the finished product for harmful substances — it does not require organic fiber or verify production practices. A polyester garment can carry OEKO-TEX certification if it passes chemical safety testing. GOTS requires organic fiber and covers the whole supply chain. They serve different purposes and are both genuinely valuable — they're not interchangeable.

What is 6A mulberry silk and why does the grade matter?

Silk is graded on a scale (A through 6A) based on the uniformity, length, and quality of the fiber filament. 6A is the highest grade — it produces the smoothest, most lustrous, most durable fabric. Lower grades are used in budget silk products and result in fabric that pills more quickly and loses its sheen after washing. For sleepwear you're investing in for years of nightly use, grade matters as much as momme weight.

What does 19-momme mean and why did More Sunday choose it?

Momme is the weight measurement for silk fabric — the higher the number, the denser and heavier the weave. More Sunday uses 19-momme deliberately: it's substantial enough to drape beautifully, hold its shape through washing, and feel unmistakably luxurious, while being light enough to sleep in comfortably across all seasons without overheating. Heavier weights exist, but for sleepwear specifically, 19-momme is the considered sweet spot.

Can EDC exposure through fabric really affect hormones?

Research on EDCs and sleepwear specifically is still emerging — it would be inaccurate to claim "this pajama fabric is causing your hormonal issue." What the research does establish is that EDCs are present in many textiles, that dermal absorption of textile chemicals occurs, and that EDCs interfere with hormonal pathways at various exposure levels. The relationship between cumulative, low-level exposure and long-term health outcomes is an active area of research. Given that uncertainty, reducing unnecessary exposure in a high-contact, long-duration category like sleepwear is a reasonable and well-supported precautionary choice.

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Sources & Footnotes

1. The Plastic Detox. Netflix, March 2026. Hosted by Dr. Shanna H. Swan, PhD, Professor of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai. Three of six couples with unexplained infertility conceived following the 90-day intervention. The documentary explicitly covers synthetic textiles and petrochemical dyes as a source of phthalate and bisphenol exposure. Also reported by: TODAY, March 17, 2026; PIRG, March 31, 2026; Innovation in Textiles, April 8, 2026.
2. Humans spend approximately one third of their lives asleep — roughly 26 years over a 79-year lifespan at 8 hours per night. NeuroLaunch, "Sleep Duration in a Lifetime," 2026. neurolaunch.com
3. National Institute of Environmental Health Sciences (NIEHS). "Endocrine Disruptors." niehs.nih.gov/health/topics/agents/endocrine. Accessed 2026.
4. WHO and NIEHS both recognize EDCs as a significant global health concern. See NIEHS Endocrine Disruptors page and WHO Global Assessment of the State-of-the-Science of Endocrine Disruptors.
5. Wallace DA, et al. "Is exposure to chemical pollutants associated with sleep outcomes? A systematic review." Sleep Medicine Reviews. Published June 2023. PMC10528206. See also: Associations between EDC exposure and sleep in midlife women, PMC10464830, May 2023.
6. Azo dyes comprise 60–70% of all fabric colorants. Earth Day, "Toxic Textiles: The Chemicals in Our Clothing," March 2024. earthday.org
7. Disperse azo dyes have low molecular weight and lipophilic nature enabling skin penetration. Alzheimer's Drug Discovery Foundation, "Textile Toxins," October 2023. alzdiscovery.org
8. Some disperse azo dyes shown to be mutagenic and genotoxic via aromatic amine release. Ibid.
9. Heat, moisture, and friction increase dermal absorption of textile chemicals. Vibrant Body Company, "Toxic Clothing Materials," April 2026. vibrantbodycompany.com
10. Phthalates linked to hormonal disruption. NIEHS, "Endocrine Disruptors." Multiple studies including: Phthalate Exposures Associated With High Numbers of Preterm Birth, NIEHS, April 2024.
11. Bisphenols linked to hormonal imbalances and reproductive concerns. University Hospitals, "Do Your Child's Clothing, Bedding and Mattress Have Toxic Chemicals?" May 2025. uhhospitals.org
12. PFAS linked to immune disruption, liver damage, developmental issues. Naturepedic, "Endocrine Disruptors in Your Home," April 2026. naturepedic.com
13. Formaldehyde classified as a carcinogen by IARC and U.S. National Toxicology Program. Earth Day, "Toxic Textiles," 2024.
14. PBDEs and flame retardants classified as endocrine disruptors. NIEHS, "Endocrine Disruptors."
15. Chlorine bleach and chlorobenzene solvents in textile processing. Earth Day, "Toxic Textiles," 2024.
16. Skin permeability varies by body area; breast tissue and inner areas have higher absorption rates. Vibrant Body Company, 2026.
17. Heat and moisture increase chemical absorption through skin. Sustainable Jungle, "Is Polyester Bad for You?" May 2026. sustainablejungle.com
18. Washing before first wear removes significant residual chemicals. Sustainable Jungle, 2026.
19. "Natural," "clean," and "pure" are unregulated textile marketing terms without legal definition. Hemptique, "OEKO-TEX vs GOTS Certification," 2025. hemptique.com
20. Sericin has natural antimicrobial resistance and has been shown to improve skin elasticity. Morton Mulberry Silk, "6 Reasons Mulberry Silk is Good for You." mortonmulberrysilk.com
21. Silk amino acids including glycine, alanine, and serine help skin retain moisture. Promeed, "Mulberry Silk Protein: Gentle on Sensitive Skin," April 2026. promeed.com
22. Mulberry silk naturally hypoallergenic; recommended by dermatologists for eczema, rosacea, psoriasis. Mulberry Park Silks, "Is Silk Bedding Hypoallergenic." mulberryparksilks.com
23. Conventional cotton accounts for approximately 16% of global insecticide sales. Widely cited figure from the Pesticide Action Network and Textile Exchange. See Textile Exchange Organic Cotton Market Report.
24. Bamboo viscose processing involves toxic solvents including carbon disulfide. Orbasics, "OEKO-TEX vs GOTS," April 2026. orbasics.com. See also FTC guidance on bamboo textile labeling.

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This article is for informational purposes only and is not intended as medical advice. If you have specific health concerns related to chemical exposure or hormonal health, consult a qualified healthcare provider. The research on textile chemicals and health outcomes is ongoing — citations reflect the state of evidence as of 2026.