Cup Starter Bundle vs Menstrual Discs: which is safer?
Flex Cup Starter Bundle is our pick: better on PFAS and on the overall hazard picture.
Our pick
Flex
Cup Starter Bundle
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleResidual manufacturing compounds / silicone impurities
PossibleMold or bacterial colonization from improper storage
Flex
Menstrual Discs
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleSilicone degradation and particulate shedding
PossibleAllergen/irritant sensitivity to silicone additives
ReportedBacterial colonization from improper cleaning
Where these two actually differ
- We flag Residual manufacturing compounds / silicone impurities and Mold or bacterial colonization from improper storage on the Flex and not on the Flex.
- We flag Silicone degradation and particulate shedding, Allergen/irritant sensitivity to silicone additives, Bacterial colonization from improper cleaning and Off-gassing or odor from manufacturing residues on the Flex and not on the Flex.
- The Flex is Medical-grade silicone, no added fluoropolymers where the Flex is Medical-grade silicone, which is most of the difference in these two grades.
- These two are level, close enough that price and fit should decide it rather than our grade.
Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →
More menstrual cups: see the full ranking