Basic Mid-Rise Period Brief vs Cotton Starter Set Period Underwear: which is safer?
Modibodi Basic Mid-Rise Period Brief is the clear pick. Thinx Cotton Starter Set Period Underwear carries a failing PFAS grade, and we never recommend buying a failing product.
Our pick
Modibodi
Basic Mid-Rise Period Brief
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleWater-resistant coating degradation
PossibleMicrobial growth and odor with improper care
Thinx
Cotton Starter Set Period Underwear
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
ReportedPFAS in waterproof coating (separate grading)
PossibleCoating degradation and particle shedding
PossibleBacterial growth if moisture is trapped
Where these two actually differ
- We flag Water-resistant coating degradation and Microbial growth and odor with improper care on the Modibodi and not on the Thinx.
- We flag PFAS in waterproof coating (separate grading), Coating degradation and particle shedding and Bacterial growth if moisture is trapped on the Thinx and not on the Modibodi.
- The Modibodi is organic cotton blend with water-resistant coating where the Thinx is Cotton + proprietary waterproof/absorbent layer coating, which is most of the difference in these two grades.
- The gap is 75 points, wide enough that this is not a close call, and the Modibodi is the one to buy.
- We are less certain about the Thinx grade, at 45% confidence against 85%, because it discloses less.
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 period underwear: see the full ranking