What the Research Says About Menstrual Discs

 

If you've spent any time on period-product social media lately, you've probably seen someone rave about a menstrual disc, the flexible, saucer-shaped product that sits differently than a cup and, according to fans, disappears entirely once it's in. If you've also felt a little skeptical about that, you're not alone. Menstrual discs are still a newer, less-studied product category than pads, tampons, or cups. So we looked at what's actually been published: two studies that test discs directly, one systematic review of chemicals in period products generally, and one large systematic review of menstrual cup safety that's relevant because of how discs are made.

What is a menstrual disc, exactly?

A menstrual disc is a flexible collection device you fold and insert like a tampon. Instead of sitting vertically in the vaginal canal the way a classic bell-shaped cup does, it opens into a saucer shape and sits horizontally, tucked into the vaginal fornix — the space behind the cervix, wedged behind the pubic bone (Masvawure & Durodola, 2026). Because it sits above and around the cervix rather than against the vaginal walls, many users report not feeling it once it's positioned correctly, and because the vaginal canal itself stays clear, disc use during intercourse is possible with some designs.

Discs and cups: different shape, often the same material

It's worth separating two things that get blurred in most period-product marketing: shape and placement versus material. A disc and a bell-shaped cup are genuinely different products, different fit, different insertion technique, different capacity. But many discs and cups, including the Mooneva disc, are molded from the same category of material: medical-grade silicone. A 2019 systematic review and meta-analysis of menstrual cups, pooling 43 studies and roughly 3,300 users across low-, middle-, and high-income countries, notes that cups are typically made from medical-grade silicone, rubber, latex, or elastomer, and reports no increased risk of infection, no adverse effect on vaginal flora across 507 women in four studies, and no vaginal tissue damage identified on follow-up exam (van Eijk et al., 2019).

That review is about cups, not discs, and we want to be precise about what it does and doesn't tell you. It doesn't prove anything about how a disc fits, how much it leaks, or how it performs during eight hours of wear. What it does offer is a large, pooled data point on the material itself: when a menstrual product is made from certified medical-grade silicone, that material has a well-documented safety track record in vaginal use. Where a disc is made from that same certified silicone, this is a reasonable, if indirect, basis for baseline confidence in the material, separate from any claim about the disc's design or performance.

There's a second, more literal connection worth mentioning. One of the earliest studies of a fornix-placed menstrual device, a compressible, single-use device called the Softcup, tested in a US clinical trial of 406 women across seven centers, describes a product that sits "between the posterior fornix and the notch behind the pubic bone" (North & Oldham, 2011). That's the same anatomical placement modern discs use, even though the Softcup itself is a disposable cup, made from a different proprietary polymer blend, not a reusable silicone disc. We're not treating that study as disc data, the authors themselves call it a vaginal cup throughout, and it isn't reusable, but it's an honest data point that fornix-placed, behind-the-pubic-bone devices have been safely studied in a clinical setting for over a decade.

Does it leak?

In one of the first dedicated studies of disc use, a small pilot at a Massachusetts college where fourteen students tried a disc brand over two menstrual cycles, half of participants experienced some leakage (Masvawure & Durodola, 2026). For most, it was minor: blood that didn't make it through to their clothes. But three of the fourteen had a genuinely significant leak at some point, usually linked to the disc filling up more than expected, not being seated correctly, or emptying unexpectedly during a movement like squatting.

Table 1. Leakage and insertion experience in a 14-person disc pilot

Source: Masvawure & Durodola (2026), Table 1 and Results.

Do people actually stick with it?

This is where the disc really shines. In the college pilot, the overwhelming majority of participants, thirteen out of fourteen, said they wanted to keep using the disc as their main period product going forward, even the ones who'd struggled with insertion at first (Masvawure & Durodola, 2026). Nearly two-thirds rated it more comfortable than whatever they'd used before, citing no strings, less odor, and far fewer changes during the day. Several described it as genuinely changing how their period felt to live with; one participant put it simply, saying that once she got the hang of it, she could go about her whole day and "didn't even notice it." That's a meaningful signal. People don't usually commit to a product with a learning curve unless what's on the other side of it feels worth it, and in this small study, almost everyone said it was.

Is insertion hard?

Maybe at first. In the same pilot, more than half of participants struggled the first time, the folded shape would slip, the rim felt too firm without lubrication, or they weren't sure they'd tucked it correctly behind the pubic bone. The good news: nearly all of them said it got easier with practice, often after watching an instructional video or trying it in the shower. 

A separate, larger study of the Softcup found that 81% of over 400 women could insert and remove it correctly on their first try using nothing but written instructions (North & Oldham, 2011). Again, that's a cup study, referenced here only because it involves the same anatomical placement, it suggests a learning curve is common to fornix-placed products generally, and that most people get past it quickly, not that this specific percentage applies to any given disc.

What about removal?

Removal was rated easy by most participants in the disc pilot, particularly with a pull-loop feature. But almost everyone who tried it mentioned the same thing: it's messy, and several avoided changing in public restrooms because of it (Masvawure & Durodola, 2026). This mirrors long-standing reports about menstrual cups generally, messiness during removal appears to be a shared trait of any product that collects rather than absorbs blood.

Does it actually hold more blood?

This is the one area where discs have direct, quantitative lab evidence behind them. Researchers at Oregon Health & Science University tested 21 menstrual products — pads, tampons, cups, discs, and period underwear — using human red blood cells, a closer stand-in for menstrual blood than the water or saline manufacturers typically use for their own capacity claims (DeLoughery et al., 2024). One disc held 80 mL before overflowing, the highest of any single product tested. On average, discs held about 61 mL, noticeably more than cups (~27 mL), pads (~39 mL), tampons (~28 mL), or period underwear (~2 mL).

Figure 1. Average product capacity by category (ex vivo bench test, human red blood cells)

Recreated from data reported in DeLoughery, Colwill, Edelman & Samuelson Bannow (2024), BMJ Sexual & Reproductive Health. Each product was tested once, under static lab conditions — not while worn.

It's worth being precise about what this proves and what it doesn't. This was a bench test, blood poured onto or into an unworn product sitting still on a table, tested once per item, not measured inside a body over a day of normal movement. Real-world capacity is likely different. But as a controlled, product-vs-product capacity comparison, it's the closest thing that currently exists, and it's a genuinely strong data point in the disc's favor.

Is it safe?

Safety of the material, there's an indirect reassurance available. The large pooled review of menstrual cup safety mentioned earlier — 43 studies, ~3,300 users, products made largely of medical-grade silicone — found no increased infection risk, no adverse effect on vaginal flora across the studies that measured it, and no vaginal tissue damage on follow-up exam (van Eijk et al., 2019). Where a disc — like Mooneva's — is manufactured from that same category of certified medical-grade silicone, this offers a reasonable basis for baseline confidence in the material. 

Table 2. What's been directly tested vs. what's inferred by material similarity

What about sleeping, exercising, or sex?

In the disc pilot, most participants (about 86%) wore the disc overnight without issues and found it comfortable enough not to think about. Many kept up with normal workouts and daily activities. One notable exception: for a couple of participants, squatting specifically triggered the disc to empty on its own, a documented feature called "auto-dumping," which some found convenient and others found inconvenient depending on timing (Masvawure & Durodola, 2026).

As for intercourse, none of the studies reviewed here tested disc use during sex directly. The design logic, that a disc leaves the vaginal canal clear, unlike a vertically-seated cup, is anatomically sound and is echoed in how the fornix-placed Softcup was described in clinical research (North & Oldham, 2011), but it hasn't been measured with disc-specific data. Treat it as a plausible, design-based claim rather than a proven one.

What first-time users should realistically expect

• Your first insertion attempt might not go smoothly, that's common (57% in the pilot study), and it usually improves with practice.
• Removal is generally manageable but reliably messier than a tampon change.
• Leakage happens to roughly half of new users in small early studies, usually minor; a smaller group experiences a genuinely significant leak, often tied to overfilling.
• In lab testing, discs hold more blood than most other product types, a real, measured advantage, though not yet separately confirmed with in-vivo testing.
• We have good pooled evidence that medical-grade silicone, as a material, has a strong safety track record in vaginal use. We do not yet have disc-specific chemical-exposure or infection-risk research for any brand.

About the Mooneva disc specifically

The Mooneva disc is manufactured in an ISO 13485–certified facility, from FDA-listed, medical-grade silicone. This is a manufacturing and quality-system fact about how the product is made, not a clinical claim, it means the facility follows the recognized international quality-management standard for medical devices, and the silicone used meets the FDA's material-listing requirements.

What researchers still don't know

We don't have chemical-exposure data for discs, a dedicated disc microbiome or TSS study, data on disc use with an IUD, large or diverse-population disc studies (the main disc-specific research here involved fourteen college students at one school), or long-term data beyond a couple of menstrual cycles. Anyone telling you discs are "clinically proven safe" or "chemical-free" is going further than the current research supports, and so are we, if we ever say it that way. What we can say, honestly: the material category is well studied and reassuring, and the disc-specific user experience and capacity data that does exist is genuinely encouraging.

The bottom line

Menstrual discs seem to work well for a lot of people who get past an initial learning curve, high capacity, comfortable wear, and enough satisfaction that in one small study, the vast majority of first-time users wanted to keep using it. The material they're made from, medical-grade silicone, has a strong safety record from a large body of related cup research. But the disc-specific research base is still young and small. If you try one, go in expecting a real adjustment period, a messier removal process than you're used to, and some open questions about disc-specific safety that simply haven't been studied yet, not because anything is known to be wrong, but because almost nobody has looked.

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References

1. 1. Marroquin J, Kiomourtzoglou M-A, Scranton A, Pollack AZ. Chemicals in menstrual products: A systematic review. BJOG. 2024;131(5):655–664. https://doi.org/10.1111/1471-0528.17668
   2. North BB, Oldham MJ. Preclinical, Clinical, and Over-the-Counter Postmarketing Experience with a New Vaginal Cup: Menstrual Collection. Journal of Women's Health. 2011;20(2):303–311. https://doi.org/10.1089/jwh.2009.1929
   3. Masvawure TB, Durodola R. "The Disc Will Always Win!": Qualitative Pilot Study Findings on the Acceptability of Reusable Menstrual Products Among College Students on a U.S. Campus. American Journal of Health Promotion. 2026;0(0):1–9. https://doi.org/10.1177/08901171261469375
   4. DeLoughery E, Colwill AC, Edelman A, Samuelson Bannow B. Red blood cell capacity of modern menstrual products: considerations for assessing heavy menstrual bleeding. BMJ Sexual & Reproductive Health. 2024;50(1):21–26. https://doi.org/10.1136/bmjsrh-2023-201895
   5. van Eijk AM, Zulaika G, Lenchner M, Mason L, Sivakami M, Nyothach E, Unger H, Laserson K, Phillips-Howard PA. Menstrual cup use, leakage, acceptability, safety, and availability: a systematic review and meta-analysis. The Lancet Public Health. 2019;4(8):e376–e393. https://doi.org/10.1016/S2468-2667(19)30111-2