Personal Care
Period &
Bladder Care
Pads, tampons, liners, cups, discs, period underwear, bladder-leak underwear and cloth pads — held against the most absorbent tissue the body has, for days at a time, for decades.
This is not a page about fear. It is a page about a question almost nobody thought to ask until recently, and about what changed at Shake before we felt able to write it.
A person who menstruates may use more than ten thousand of these products in a lifetime. That figure comes from a 2022 review in Current Environmental Health Reports, and what is remarkable about it is not the number. It is that the number sat there, uncontroversial, for years, without anyone treating it as a reason to look closely at what the products are made of.
The materials themselves are not exotic. Cotton, , polyethylene, polyester, silicone — the same cast of characters that turns up in a t-shirt or a takeaway container. What makes this category different is not the ingredient list. It is the address.
The vaginal wall is a mucous membrane. It has no keratinised outer layer to slow anything down, it is richly supplied with blood, and it is folded in a way that considerably increases its surface area. This is not a controversial claim or an activist framing — it is precisely why the route is used to deliver medication. And as the same review puts it plainly: chemicals absorbed by the vagina “bypass by the liver and directly enter systemic circulation.”
Swallow something and the liver gets first look at it. Absorb it here and it does not.
That is a fact about anatomy, not an accusation about any product on any shelf. But it is the reason this page exists — and the reason we rewrote part of our own scoring standard before writing a word of it.
The Materials
What these products are actually made of
Most of this information is not on the box. There is no federal requirement in the United States to list what is in a menstrual product, which is why individual states have had to legislate for it — New York became the first to mandate ingredient labelling on menstrual products, and California followed. Here is the honest inventory, product by product.
Scroll table sideways →
| Product | What it is typically made of | What that means |
|---|---|---|
| Disposable pads & liners | Wood-pulp fluff core, , polypropylene topsheet, polyethylene backsheet, adhesive strip, release paper | Friends of the Earth cites estimates of up to 90% plastic in a disposable pad, and describes a single pack as roughly equivalent to four plastic bags. |
| Tampons | Cotton, rayon/viscose or a blend; cotton or polyester string; optional cardboard or plastic applicator | The FDA states that cleared tampons are made of cotton, rayon or a blend, using a bleaching process free of elemental chlorine. Absorbency is standardised and printed on the box — the reason “use the lowest absorbency you need” is workable advice. |
| Menstrual cups & discs | Medical-grade silicone, thermoplastic elastomer, or latex rubber | “Medical grade” is a family of materials, not a single specification. A brand that names the actual grade is telling you more than one that does not. |
| Period & bladder-leak underwear | Face fabric (cotton, viscose or synthetic), a wicking layer, an absorbent core (frequently polyester ), and a waterproof membrane, usually | Four materials, four questions. Composition is very often published for the outer fabric only. Under Shake’s Fibre Integrity rule, the layer that does the work sets the ceiling — a cotton gusset does not lift a polyester core. |
| Reusable cloth pads | Cotton, hemp or viscose top layer, absorbent core, PUL or fleece backing, poppers | The same layer question. And “bamboo” here is two entirely different materials depending on how it was processed — see below. |
Compositions vary by brand and product line. This table describes what is typical, not what is universal — the point of the page is that you should be able to read the specific answer for the specific product, from the brand.
Awareness
What to be mindful of
Six things worth knowing. Some are well established, some are genuinely unresolved, and we have tried very hard to tell you which is which — including where the honest answer is that nobody knows yet.
Fragrance, in a product held against mucosa
On the Shake list, undisclosed fragrance sits at Tier 3 — not a toxicant in itself, but a labelling loophole. “Fragrance” or “parfum” can stand in for dozens of undeclared components, including and known allergens.
Nothing about the ingredient changes here. What changes is where it is worn, and for how long. Scented liners and deodorised pads are the everyday version of this question.
Source: shake-avoid-toxin-list, entry “Undisclosed fragrance”, Tier 3 · EU allergen labelling rules
Metals measured in tampons — and the caveat that matters
In 2024 a research team measured sixteen metals in thirty tampons across fourteen brands, and detected all sixteen. Lead appeared at a geometric mean of 120 ng/g, cadmium at 6.74 ng/g, arsenic at 2.56 ng/g. Lead was higher in non-organic tampons; arsenic was higher in organic ones.
Then the part that rarely survives the headline. The lead author: “We don’t yet know if those metals come out of the tampon and if they do, we don’t know whether they can get into the bloodstream.” The study measured what is in the material, using an acid digestion far harsher than any human body. The FDA has since opened its own review.
Worth knowing. Not yet worth a conclusion.
Source: Shearston JA et al., Tampons as a source of exposure to metal(loid)s, Environment International 2024;190:108849 · lead author and independent analytical chemists quoted in C&EN, July 2024 · FDA review reported by UC Berkeley School of Public Health
PFAS in reusable products — and the better half of the finding
Researchers at Notre Dame and Indiana University tested more than seventy reusable products, breaking them into 323 individual layer samples. Around a third of period underwear and a quarter of reusable pads were — treated on purpose with -based chemistry, not picked up by accident.
PFAS is Tier 1 on the Shake list — persistent, bioaccumulative, with the strongest evidence weight we assign. But the more useful finding is the inverse: most products tested had none. As the lead author put it, PFAS “must not be essential in the manufacture of reusable feminine hygiene products.” Which means a brand using them has made a choice, and a brand avoiding them can prove it.
Source: Wicks A et al., Environmental Science & Technology Letters, via University of Notre Dame, 2025 · shake-avoid-toxin-list, “PFAS”, Tier 1
The certificate that covers the cotton, not the applicator
Certifications are issued for something specific — usually a fabric at a mill, not a finished product at a brand. A company can hold an entirely genuine certificate while the component you are most curious about sits outside its scope.
There is a neat worked example in this category. Earlier versions of the GOTS standard permitted “plant-based plastic” applicators on certified organic tampons. According to Natracare founder Susie Hewson, who campaigned to close it, as little as 20% plant content qualified for that description — the rest being polyethylene. Version 6.0 now requires applicators to be plastic-free, biodegradable or compostable.
The label was accurate. The impression it left was not.
Source: Natracare / Susie Hewson on GOTS v6.0 (brand’s own account, attributed) · ShakeUp v1.3, Part 7.1, the scope trap
Plastic you were never told about, in something designed to be binned
Beyond what the body meets, there is what the bin meets. Friends of the Earth cites up to 200 kg of menstrual products discarded per person over a lifetime, and beach surveys averaging 4.8 pieces of menstrual waste per 100 metres of British coastline.
Nothing about this is a reason for guilt. It is a reason to know that a “cotton” pad may be mostly polymer, and that the choice between disposable and reusable is a material choice as much as a habit.
Source: Friends of the Earth UK, Plastic periods: menstrual products and plastic pollution
Absorbency claims with no shared standard behind them
Tampon absorbency in the US is standardised and printed on the packet, which is the only reason the guidance to use the lowest absorbency you need is actionable at all.
Reusables have no equivalent. When period or bladder-leak underwear says it holds “three tampons’ worth”, there is no common test method behind the comparison — each brand may measure differently, and until very recently the field tested absorbency with saline and water rather than blood, which behaves quite differently.
So we report what a brand claims, attributed to the brand, and we do not repeat it as a measurement.
Source: US FDA on tampon absorbency labelling · reporting on menstrual-product absorbency testing, Scientific American, 2023 · ShakeUp SOP v1.3, Part 6.2
Conscious Alternatives
What to look for instead
Six things you can actually check, none of which require trusting a marketing claim. Most of them are questions rather than products — which is deliberate, because the answer changes by brand and by year.
Composition, published layer by layer
Not “cotton and bamboo”. Which fibre, in which layer, at what percentage. A brand that publishes four layers is telling you it knows what is in all four.
Where composition is not published at all, Shake treats it as the lowest band on our Fibre Integrity scale — not as a punishment, but because a brand can lift its own ceiling any time simply by saying.
Standard: ShakeUp SOP v1.3, Part 4C
A certificate number, not a badge
Three things make a certification checkable: the number as issued, the institute that issued it, and which components it covers. Any one missing and it cannot be verified.
Worth knowing: since 1 January 2024, prohibits intentional PFAS in certified articles. A verified certificate covering every layer of a garment substantiates a PFAS-free claim more firmly than the brand’s own wording ever could.
Standard: ShakeUp SOP v1.3, Part 7.1 · OEKO-TEX restricted substances
No added fragrance
The shortest possible answer to the disclosure problem. If there is no scent, there is no undisclosed scent.
Where a product is scented, look for the components named individually. “Fragrance” as a single word is the loophole, not the ingredient.
Standard: shake-avoid-toxin-list, “Undisclosed fragrance”, Tier 3
The word that follows “bamboo”
Mechanically processed bamboo — crushed, retted, combed into fibre, sometimes sold as bamboo linen — and bamboo viscose are not the same material. The second is cellulose dissolved in strong chemicals and extruded. The plant origin survives; very little else does.
US FTC rules require the second to be labelled “rayon made from bamboo” or “viscose from bamboo”. A brand writing it correctly is a brand that understands its own supply chain.
Standard: ShakeUp SOP v1.3, Part 6.1 · US FTC textile labelling rules
A silicone grade with a name
“Medical grade” describes a category. The useful version names the specification, the manufacturer, and whether the finished cup — not just the raw material — was tested.
Cups and discs are among the few products here with a genuine peer-reviewed evidence base behind their safety and function, which is a point in their favour and worth saying plainly.
Source: van Eijk AM et al., systematic review and meta-analysis, The Lancet Public Health, 2019
A bleaching process stated on the record
The FDA’s position is that the absorbent fibres in cleared tampons are made “with a bleaching process that is free from elemental chlorine, which also prevents products from having dangerous levels of dioxin.”
So a brand stating “elemental chlorine free” or “unbleached” is confirming something already expected of it, in writing. That is not a marketing claim — it is a brand putting its process where you can see it.
Source: US FDA, The Facts on Tampons — and How to Use Them Safely
Behind the scoring
Every ShakeUp score multiplies the strength of the evidence by the route of exposure — how readily something reaches the bloodstream. Until this week, the highest figure on that scale was 1.3, shared by food, leave-on skincare and supplements.
There was no figure at all for the route through , or the vaginal route — the highest-absorption routes we score, and the ones this entire category rests on. Publishing the page first and fixing the model afterwards would have meant every score on it needed redoing.
So we set two: 1.7 for anything worn internally — tampons, cups, discs — and 1.5 for external intimate contact — pads, liners, period and bladder-leak underwear. We also added a third exposure-frequency band, cyclical, because a product worn for five consecutive days every month for forty years is neither “daily” nor “occasional”, and pretending otherwise would have quietly understated the whole category.
The reasoning, the sources and the arithmetic are all written down, including the number we decided not to use and why.
How we scoreFeatured Brand
EverLeakProof
This space held three questions for three weeks. We said that if the answers came we would say so, and that if they did not, that would be on the page too. They have not come, so here is the score and here is why it looks like this.
66.75%
Worth a Pause
People55 · ceiling
Animals88.5
Gaia73.5
Frequency50 · ceiling
Each pillar starts at 100. Evidenced concerns deduct, verified virtues add back, and some things set a ceiling instead. The overall is the average of the four. Scored under SOP v1.4, the version that introduced the Disclosure Default.
What the number is made of
What carried it. A washable garment that replaces disposable pads and liners, which we credit directly on the planet pillar. Nothing in the construction is currently evidenced against the person wearing it.
What holds it down. The absorbent core is polyester and polyamide, and the leak barrier is a thin waterproof film bonded to fabric. Those two layers do the actual work of the garment, and synthetic load-bearing layers set a ceiling on the Frequency pillar whatever else is true. That is not a criticism of the making. It is what the material is.
And the People pillar is capped at 55 rather than scored in full. Not because we found something in the product. Because we asked three questions and the answers have not arrived.
- The certificate number, the issuing institute, and which of the four layers it covers. We check every certificate by its number rather than its name.
- How odour control is achieved, if any finish is used. The outer is bamboo viscose, and the antibacterial property raw bamboo has does not survive that manufacturing process — so any odour performance in the finished garment comes from something applied afterwards.
- Third-party testing behind the PFAS-free claim. A brand’s own assurance is not the same thing as a lab result, and we hold every brand on Shake to that line.
We asked on 18 August, and again on 24 August with the full working attached, and said we would publish on 29 August. EverLeakProof has been in touch since. The three answers have not. That is what the cap records — not a finding against the product, but the distance between what we could check and what we were asked to take on trust.
This costs nothing to change. A certificate number we can look up, a named laboratory report, a stated mechanism — any one of them lifts the ceiling and the page changes the same week. It is not tied to the commercial arrangement, and it does not expire.
Shake is an EverLeakProof affiliate through Awin and earns a commission if you buy through the link on this card. That arrangement began on 13 August, before this score was calculated, and it had no part in the number: the commission is identical whether the product scores 45% or 95%, and the score was reached under the same rules and the same materials repository as every other brand on Shake.
The photograph is EverLeakProof’s own, supplied through Awin. Brand imagery appears on Shake only where a relationship exists, and this one does. The words beside it are ours, as they are everywhere on this site — we publish product photography, never advertising, and no claim printed on a supplied image is repeated as ours.
On Our Radar
Brands we are watching
These carry no score because we have not assessed them yet — not because of anything they have or have not done. There are no buy buttons because Shake has no affiliate relationship with any of them. They are here because they answer at least some of the questions above in public, on their own websites, where anyone can check.
Disposables
A UK company that has built its whole position on organic cotton and on removing plastic from disposables — and whose founder campaigned publicly to close the “plant-based applicator” gap in the GOTS standard rather than use it.
Interesting to us for the campaigning as much as the products. A brand arguing to make its own certification harder to obtain is a rare thing.
Cups & discs
Cups and discs which the brand states are made from medical-grade silicone. This is the corner of the category with the strongest independent evidence behind it — a 2019 systematic review in The Lancet Public Health found cups performed comparably to other products on leakage, with no evidence of increased safety concerns.
Reusable, so it also sidesteps the disposal question entirely.
Reusable cloth pads
Cloth pads in organic cotton, made in the USA, and one of the longest-running names in reusables. The appeal here is material simplicity: a single fibre doing the absorbing, with no membrane and no core to ask questions about.
The plainest illustration on this page of what “fewer layers, fewer questions” actually looks like.
Descriptions are drawn from each company’s own published material and from the independent sources cited elsewhere on this page. Shake has not verified any certification held by these brands and awards no score on the basis of one. Inclusion here is editorial interest, not endorsement.
Material Awareness
The four words worth learning
Almost everything on this page reduces to four terms. Learn these and you can read any product page in this category in about ninety seconds.
Viscose & rayon
Cellulose — from wood, or from bamboo — dissolved in strong chemicals and extruded as fibre. Soft, absorbent, plant-derived, and heavily processed. Not a villain; simply not the same thing as the plant it came from.
PUL
Polyurethane laminate. The thin waterproof membrane inside almost every piece of period and bladder-leak underwear. It is what stops the leak, it is a plastic film, and it is very rarely mentioned in the composition a brand chooses to publish.
Superabsorbent polymer (SAP)
The gel that makes a thin disposable pad hold what it holds. Usually sodium polyacrylate. It is the reason modern pads are thin, and part of the reason they are largely plastic.
Microfibre
Very fine synthetic filament, usually polyester or polyamide, often the absorbent core of period underwear. Excellent at wicking. Sheds fibres into the wash, which is where the Animals and Gaia pillars take an interest.
There is no verdict at the end of this page, and that is not us hedging. The metals study does not yet know whether metals leach. The absorption research is clear about the route and quiet about the magnitude. Most reusable products contain no PFAS at all, and a third of one category does.
What we can say is smaller and more useful: this is the most absorbent route on our entire scale, the products are worn for a very long time in total, and almost none of the information you would need is required to be on the box.
So the question is not whether to be worried. It is whether the brand you buy from can answer three straightforward questions about its own product. Most cannot yet. The ones that can are worth knowing about — and that is the whole job of this page.
Words on this page
We would rather explain a word than avoid it. Tap any dotted term above, or read them here.
- SOP
- Standard Operating Manual — Shake’s written scoring rulebook. It sets out how a product is assessed, what counts as evidence, and what each score means. It is versioned, and every score records which version produced it, so you can check what that version actually required.
- The skin of the vulva
- The vulva is the external genitals — the parts you can see. Distinct from the vagina, which is internal. The difference matters here because the two absorb differently, and a product worn outside the body is not doing the same thing as one worn inside it.
- First-pass metabolism
- The liver’s first go at anything you swallow, breaking much of it down before it reaches the rest of you. Things absorbed through a mucous membrane skip that step and enter the bloodstream directly — which is why the same substance can behave very differently depending on how it gets in.
- Phthalates
- Plasticisers — they soften plastic and make scent last longer. Tier 1 on Shake’s list, because they are endocrine disruptors — substances that interfere with the body’s hormone signalling. Often not listed by name at all, but hidden inside the single word “fragrance”.
- PFAS
- A large family of synthetic chemicals used to repel water, oil and stains. They break down extremely slowly, which is why they are often called forever chemicals. Their usefulness and their persistence are the same property.
- Deliberately fluorinated
- Treated on purpose with PFAS-based chemistry, usually to make a fabric repel liquid. Worth distinguishing from contamination picked up by accident somewhere in a supply chain — one is a manufacturing decision, the other is a manufacturing failure.
- OEKO-TEX STANDARD 100
- A textile certification. Since 1 January 2024 it prohibits intentionally added PFAS. Every genuine certificate carries a number, an issuing institute, and a stated scope — which is why we ask for all three rather than accepting the logo.
- Viscose (rayon)
- A fibre made by dissolving plant cellulose in chemicals and reforming it as thread. It begins as a plant and ends as a heavily processed fibre. This is why fabric made this way from bamboo must legally be labelled “rayon made from bamboo” rather than simply “bamboo”.
- PUL
- Polyurethane laminate — a thin plastic film bonded to fabric to make it waterproof. It is the layer that stops a leakproof garment leaking, and it is the reason most of them contain plastic somewhere.
- Superabsorbent polymer
- Usually sodium polyacrylate. The gel that lets a thin disposable pad hold what it holds. It is why modern pads are thin, and part of why they are largely plastic. Often shortened to SAP.
- Microfibre
- Very fine synthetic filament, usually polyester or polyamide, often the absorbent core of period underwear. Excellent at wicking. Sheds fibres into the wash, which is where the Animals and Gaia pillars take an interest.
The label writes the score. We don’t. Only evidence moves it.
Affiliate disclosure. Shake earns commission on some links across this site. Shake is an affiliate of EverLeakProof, the brand featured above, through the Awin network — disclosed again on the card itself. That relationship began before the score was calculated and had no part in it. The three brands under On Our Radar carry no links and no commercial relationship with Shake. Our editorial positions are not for sale, and a commercial relationship is never an input to a Shake Score.
Not medical advice. Shake describes materials and exposure routes. It does not diagnose, treat or advise on any medical condition, and nothing here should be read as a claim that any product prevents or reduces one. Bladder leakage, heavy bleeding and pelvic pain are worth raising with a clinician, not a publication.
On our sources. Every factual claim on this page is attributed in the card that makes it. Where the evidence is unresolved, we have said so rather than rounding it into a conclusion. Scored against the ShakeUp Standard Operating Manual v1.4, 19 August 2026 — the version carrying the Disclosure Default applied to the featured card above.