TPE (thermoplastic elastomer) is generally considered safe for menstrual cups, though it rates slightly below medical-grade silicone in biocompatibility testing. TPE cups are free from latex, rubber, and BPA, and several brands have earned FDA registration. That said, recent lab testing has detected trace levels of certain plastic additives in TPE cups that weren’t found in their silicone counterparts, which adds nuance to the safety picture.
What TPE Actually Is
Thermoplastic elastomer is a flexible polymer that behaves like rubber but can be melted and reshaped, similar to plastic. Unlike medical-grade silicone, which is a thermoset material (meaning it holds its shape permanently once cured), TPE can be recycled and remolded. This property makes it cheaper to manufacture and gives it a slightly different feel: TPE cups tend to be softer and have a smoother, almost “skin-like” texture compared to silicone.
TPE menstrual cups do not contain silicone, rubber, latex, BPA, BPS, or heavy metals. The material is used in a range of medical and consumer products, from catheter components to baby bottle nipples. Me Luna, a German brand, is one of the most well-known TPE cup manufacturers.
How TPE Compares to Silicone in Safety Testing
Medical devices that contact the body must pass three core biocompatibility assessments before reaching the market: cytotoxicity testing (checking whether the material damages cells), irritation testing (evaluating tissue reactions), and sensitization testing (screening for allergic or hypersensitivity responses). These are outlined in the ISO 10993 standard, which applies to both TPE and silicone devices.
In head-to-head comparisons for medical applications, liquid silicone rubber scores “excellent” for biocompatibility and “very low” for toxicity, while TPE scores “good” and “low” respectively. Both pass the threshold for safe body contact, but silicone consistently edges ahead. This is one reason silicone remains the default material for implantable and internal medical devices, with TPE positioned as a capable alternative rather than the gold standard.
The Phthalate Question
A 2025 study published in Environmental Science & Technology analyzed plastic additives across a range of menstrual products, including cups made from both silicone and TPE. The findings were largely reassuring for cups overall: organophosphate esters (a class of flame retardants and plasticizers) were detected in 100% of other menstrual products but only 17% of cups.
However, the study did find phthalates in menstrual cups at low concentrations. DEHP, a plasticizer that has raised health concerns in other contexts, was detected at a median of 116 nanograms per gram. DBP, another phthalate, appeared in five out of six cups tested. Notably, one specific phthalate, DiNP, was detected only in TPE cups and not in silicone ones. The concentrations were lower than those found in reusable pads and period underwear, but they weren’t zero.
These trace amounts likely come from manufacturing environments or packaging rather than being intentionally added to the cup material. Still, the finding matters because menstrual cups sit against vaginal tissue for hours at a time, and the vaginal lining absorbs chemicals more readily than skin. No study has yet measured whether phthalates at these concentrations actually migrate from cups into tissue during normal use.
Durability and Replacement
A high-quality TPE cup can last up to 10 years, roughly the same lifespan as a medical-grade silicone cup. Earlier concerns that TPE would degrade faster haven’t been supported by real-world use data, and the choice between the two materials comes down more to personal preference around shape, firmness, and feel.
That said, TPE is more sensitive to heat during cleaning. The standard recommendation is to boil your cup for no more than five minutes between cycles. Boiling for longer can compromise the cup’s structure, and if the water evaporates, a TPE cup can melt or stick to the pot. Some users assume longer boiling means better sterilization, but there’s no evidence that extended boiling improves cleanliness. It just risks ruining the cup.
Who Should Consider a TPE Cup
TPE cups are a strong option if you have a silicone sensitivity or allergy. Because TPE contains no silicone, latex, or rubber, it sidesteps the most common material allergies associated with internal menstrual products. People who prefer a softer, more flexible cup also tend to gravitate toward TPE, as the material is naturally less rigid than silicone at comparable thicknesses.
The recyclability of TPE is another draw. Unlike silicone, which is difficult to recycle through standard municipal programs, TPE can be melted down and repurposed at end of life. If you’re choosing a menstrual cup partly for environmental reasons, this is worth factoring in.
The Bottom Line on Safety
TPE is a legitimate, tested material for menstrual cups. It passes biocompatibility standards, is free from the most concerning allergens, and has a comparable lifespan to silicone. It’s not quite as inert as medical-grade silicone, and the recent detection of trace phthalates (particularly DiNP in TPE cups specifically) is worth watching as more research emerges. For most people, either material is a safe choice. If minimizing chemical exposure is your top priority and you don’t have a silicone allergy, silicone has a slight edge. If you need a latex-free, silicone-free option or prefer a softer cup, TPE is a well-supported alternative.