Your "Medical" Wig Is Probably Plastic! What Mono, PU & "Cranial Prosthesis" Really Mean
- Hairline Illusions
- 7 days ago
- 9 min read

Figure #1 Wigs can look natural—your scalp comfort still comes first.
A Guide for Anyone Navigating Hair Loss During Medical Treatment
If you're exploring wigs during chemotherapy or for medical hair loss, you've probably heard the term "cranial prosthesis." It sounds official and medical, right?
Here's what we wish someone had told us when we started in this industry:
"Cranial prosthesis" is primarily an insurance term—not a safety certification.
We're writing this because every week we hear from people who were told their wig was "medical-grade" or "designed for chemo patients," only to experience painful reactions, scalp irritation, or worse. Nobody's trying to mislead you—but the industry terminology can be genuinely confusing.
Let's clear it up.

Figure #2 Design sets the scalp climate: films trap heat/moisture; breathable textiles allow airflow.
We Learned This The Hard Way—Then Got Silenced For Sharing It
When we first decided to serve the medical community in the early 2000s, we did what everyone said was "right." Suppliers called their caps cranial prostheses for cancer patients and "safe for sensitive skin." We dissected those caps, took their classes, and built similar units—PU films, monofilament laces, imitation "silk"—because that's what the industry taught.
Then a client told us she had to remove her wig every few hours because it wasn't comfortable.
That moment changed everything.
Back in the early 2000s there wasn't much published guidance, so we did the slow work: reverse-engineering caps, studying materials, and testing in real life. We learned the hard truths: monofilament lace is plastic (nylon/polyester), PU is plastic (polyurethane), and materials + occlusion + friction decide whether a healing scalp thrives or struggles.

Smooth textile weave (silk/cotton-type).Fine interlaced fibers; soft hand, breathable, skin-friendly.
Soft knit/pile (bamboo/modal-type).Plush, moisture-wicking surface that reduces friction on tender scalps.
Synthetic mesh lattice (plastic filaments).Tight lattice with nodes; durable but can abrade/react on sensitive skin.
Open monofilament mesh (nylon/polyester).Large diamond apertures; allows airflow but edges are plastic and can snag.
What Happened When We Shared Our Findings
In 2007–08, we shared what we were learning. We offered How to Start Your Medical Wig Business—free—to anyone who wanted to do this responsibly. We documented what we'd found:
Monofilament = nylon mesh catching on dry, fragile scalps
PU bases = polyurethane films trapping heat and sweat
No biocompatibility testing required
"Medical" primarily meant insurance-billable, not safety-tested
The industry came after us.
Angry comments flooded in. Suppliers told people our claims were false. We were called irresponsible and accused of fear-mongering. Vendors said we were scaring patients.
We were a small business facing an established industry's backlash.
We removed the blog.
Then The Research Started Appearing
Over time, we watched stripped-down versions of our outline get copied online and filled in with dangerous assumptions:
"Just get an NPI and you can sell to the medical industry."
"Lace = cranial prosthesis."
"PU and glue-heavy installs are fine for chemo patients."
That misinformation spread—even some well-meaning organizations repeat it—and patients are paying the price.
But then the peer-reviewed research started validating everything we'd been documenting since the early 2000s:
2012: Acrylates (found in wig adhesives) named American Contact Dermatitis Society's Allergen of the Year
2016-2017: Clinical trials showed the scalp reaction rates we'd been seeing
2018-2020: Studies documented the exact occlusion and adhesive problems we'd identified
Everything we were attacked for in 2007 is now published in medical journals.
We can't stay silent anymore.
The Research That Changed How We Build
What Clinical Studies Actually Show

Figure #4 Scalp redness—often improves with breathable textiles
When we dug into peer-reviewed medical research (not marketing materials), here's what we found:
Study 1: Traditional Medical Wigs & Scalp Reactions
A rigorous clinical trial in Japan followed breast cancer patients wearing medical wigs during chemotherapy:
86.7% of patients wearing traditional medical wigs developed scalp redness (erythema) by week 13
Even with redesigned hypoallergenic versions, 44.8% still developed reactions
Source: Randomized controlled trial, University of Tokyo (Trial ID: UMIN000021289)
Study 2: Occlusion & Scalp Disease
Research on alopecia patients wearing wigs found:
40% developed scalp disease from occlusion (heat/moisture trapped against skin)
Discomfort affected quality of life despite wigs improving appearance
Source: Chonbuk National University Hospital study in Annals of Dermatology
Study 3: Adhesive Reactions
Dermatology literature documents that:
Acrylates (found in many wig tapes and liquid adhesives) were named American Contact Dermatitis Society's Allergen of the Year in 2012
Case studies show confirmed allergic reactions: burning, oozing, erosions at hairlines
Symptoms often resolve only when adhesive use stops
Sources: Multiple peer-reviewed case reports in dermatology journals
What Your Wig Is Actually Made Of

Figure #5 Panel 1
a lace top — monofilament (nylon/poly)
b silicone front — industrial silicone pad
c/d stretch lace — plastic mesh zones
e elastic — pressure at perimeter
Panel 2
a lace closure front — monofilament
b/c stretch lace — plastic mesh
d silicone ear tabs — industrial silicone at pressure points
Panel 3
a — mono top
b — PU (polyurethane) panel with silicone coat
c — lace front
d — PU (polyurethane) ear tabs with silicone coat
e — lace
f — stretch lace
g — PU (polyurethane) perimeter with silicone coat
Marketing terms vs. material realities:
"Monofilament" or "Mono Cap"
What it actually is: Nylon or polyester mesh (plastic fibers)
Often marketed as "breathable"
Reality: It's mesh (which does allow some air), but it's still synthetic plastic material
Can trap heat and moisture against sensitive scalps
Can catch and snag on dry, scaly skin that's common during chemotherapy
"Skin Base" or "PU Cap"
What it actually is: Polyurethane film (plastic membrane)
Creates realistic appearance
Reality: Non-breathable barrier that traps heat and sweat
This is the "occlusion" that causes problems in the studies above
"Medical-Grade" or "Cranial Prosthesis"
What it actually means: Usually just means it's eligible for insurance reimbursement
Major patient organizations literally advise using this term for insurance purposes
It's not a biocompatibility certification or safety standard
There's no FDA requirement that these products undergo medical device testing
What Cancer Centers Actually Say
Even major cancer treatment centers acknowledge these issues:
Dana-Farber Cancer Institute notes that chemotherapy makes scalps tender and sensitive, and "some wigs can irritate the scalp." They recommend wig caps partly because they "absorb some of the perspiration that develops on the scalp"—acknowledging that excessive sweating under wigs is an expected problem requiring management.
Questions to Ask ANY Wig Vendor
You deserve real answers. Here are specific questions to copy and ask:
1. Material Transparency
"What exact materials touch my scalp?"
If they say "monofilament" → Ask: Is that nylon or polyester mesh?
If they say "skin base" → Ask: Is that polyurethane film?
If they say "lace" → Ask: What fiber is the lace made from?
2. Heat & Moisture Management
"How does your design prevent heat and moisture buildup?"
Synthetic materials (mono, PU) create occlusion
What specific features address this? (Ventilation holes? Moisture-wicking liners?)
3. Biocompatibility Evidence
"Do you have ISO 10993 test data for skin irritation and sensitization?"
ISO 10993 is the international standard for biocompatibility of medical devices
If they don't have it, ask what testing they do have for prolonged skin contact
4. Adhesive Safety Plan
"What's your protocol for adhesive use on sensitive scalps?"
Do they offer patch testing before full application?
What alternatives exist to minimize adhesive use?
Are their adhesives acrylate-free? (If not, allergy risk is higher)
5. Wear-In Period
"Do you recommend a gradual wear-in period?"
Responsible providers suggest 2-4 hours the first day, monitoring for reactions
Immediate all-day wear doesn't allow you to catch problems early

1) Antimicrobial, biodegradable wig — rare/innovativeWhat it is: Textile-forward build (e.g., silk/cotton/cellulose) with an antimicrobial treatment.Why it matters: Lowest occlusion and friction among the three; still ask for ISO 10993 irritation/sensitization data and finish durability after washing.
2) Antimicrobial polymer cranial prosthesis — less common/emergingWhat it is: Polymer base with antimicrobial additive/finish; can appear very “invisible.”Why it matters: Still plastic at skin contact—manage occlusion/friction; request ISO 10993 + proof the treatment is skin-safe.
3) Cranial prosthesis (standard) — most prevalent/legacyWhat it is: Insurance-labeled build, typically monofilament lace and/or PU film.Why it matters: Highest risk for heat/sweat trapping and edge friction on sensitive scalps; minimize adhesives, patch-test (acrylates), consider breathable liners.
What We Changed—And Why It Matters
To be clear: some people tolerate lace and PU just fine. But many do not. And when someone receives a free wig that helps them feel whole, they'll often endure irritation rather than complain. That's exactly why our standards must be higher.
Here's what we changed based on our research and the clinical studies that followed:
Materials We Retired for Medical/Sensitive Scalps:
Monofilament and full-PU bases
Combs that dig into tender scalps
Adhesive-dependent attachment systems
Materials and Approaches We Moved To:
Biodegradable textiles where appropriate (smooth, breathable, proven in chemo headwear for decades)
Medical-grade silicone (0.03-0.08mm)—actually tested for biocompatibility, not industrial-grade—used strategically for structure, not as an occlusive barrier
Breathability designed in: ventilation zones, soft edges, reverse seams (stitching faces outward, away from scalp)
Adhesive-light protocols with staged wear-in (48–72 hrs of short cycles) before all-day wear
Client education about adhesives: acrylate-based tapes/liquids can trigger allergic contact dermatitis (burning, redness, oozing). We patch-test when use is unavoidable and default to non-glue grips/straps for reactive scalps
Why These Materials?
The chemo cap industry has used bamboo, cotton, and silk for decades because they work:
These materials don't catch on dry, scaly skin (unlike mesh)
They're naturally smooth and temperature-regulating
They can be properly sterilized between wears
They've been proven safe in headwear for sensitive scalps
We're sharing these principles not to push our products, but because they apply whether you're buying from us or anywhere else. Materials, engineering, and evidence matter more than marketing terms.
Wigs—When Skin Health Comes First
We love what wigs do for confidence and quality of life. Our commitment is simple: the part that touches your skin must be as thoughtfully engineered as what the world sees.
What you can expect from us
Material transparency—plain-language names for every layer that contacts skin.
Evidence-based design—breathable textiles, soft edges, reverse seams, and strategic, thin silicone (0.03–0.08 mm).
Honest trade-offs—why we avoid full films/mono at the perimeter for reactive scalps, and when we’ll suggest alternatives.
Care partnership—we encourage patch testing and coordination with your dermatology/oncology team.
Educational, not medical advice. Individual experiences vary.
The Bottom Line
If you're going through chemo or dealing with medical hair loss:
You can ask for evidence. You're not being difficult—you're being informed.
Reactions are common, not your fault. If a wig causes problems, that's often a design issue, not you being "too sensitive."
"Medical" terminology can be misleading. Always ask what testing backs up those claims.
Work with your dermatology/oncology team. They can help identify reactions early and suggest alternatives.
A label that says "cranial prosthesis" doesn't make a cap chemo-safe. Materials, engineering, and evidence do.
What You Can Do Right Now
Print the "Questions to Ask" section above and bring it to your next wig consultation
Share this article with your oncology or dermatology team
Don't accept "medical grade" as enough—ask for material specifics and testing evidence
Do a staged wear-in period—short cycles with a symptom log (heat, redness, itch) before committing to all-day wear
Trust your body—if something feels wrong, it probably is. Reactions aren't your fault.
You deserve informed consent about what touches your healing skin.
Fast Facts Reference
86.7% scalp redness with traditional medical wigs; 44.8% even with improved versions (RCT, PubMed: UMIN000021289)
40% scalp disease from occlusion in wig wearers (Annals of Dermatology)
Acrylates = Allergen of Year 2012; confirmed wig adhesive allergies in medical literature
Monofilament = nylon/polyester mesh (plastic)
PU/Skin base = polyurethane film (plastic, low breathability)
"Cranial prosthesis" = insurance term, not safety certification
ISO 10993 = actual biocompatibility standard to ask about
Resources & Citations
All claims in this post are backed by peer-reviewed research:
Clinical trials: PubMed (UMIN000021289)
Occlusion studies: PMC/Annals of Dermatology
Allergen data: American Contact Dermatitis Society
Material information: Industry technical specifications
FDA biocompatibility guidelines: FDA.gov
This is educational information only. Please coordinate all wig decisions with your oncology and dermatology care team. Individual experiences vary.
Questions? Comments? Experiences to share?
We're here to learn too. If you've found solutions that work, or have questions we didn't answer, please share in the comments. This is about building collective knowledge to help people make informed choices.
💙 From all of us at Hairline Illusions / HIASTI
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