Basic Mid-Rise Period Brief vs Intimates & Sleepwear Thinx for All Women's Period Underwear: which is safer?

Modibodi Basic Mid-Rise Period Brief is the clear pick. Thinx Intimates & Sleepwear Thinx for All Women's Period Underwear carries a failing PFAS grade, and we never recommend buying a failing product.

Our pick

Modibodi Basic Mid-Rise Period Brief

Modibodi

Basic Mid-Rise Period Brief

PFAS grade

Excellent 100/100

Overall grade

Excellent 92/100

Verdict

Buy

Hazard flags

⚑ 2

Material

organic cotton blend with water-resistant coating

Confidence

85%

PossibleWater-resistant coating degradation

PossibleMicrobial growth and odor with improper care

Thinx Intimates & Sleepwear Thinx for All Women's Period Underwear

Thinx

Intimates & Sleepwear Thinx for All Women's Period Underwear

PFAS grade

Poor 25/100

Overall grade

Bad 0/100

Verdict

Skip

Hazard flags

⚑ 5

Material

Nylon, spandex, cotton blend with waterproof barrier layer

Confidence

55%

LikelyPFAS in waterproof barrier (fluorinated coating chemistry unknown)

PossibleAzo dyes in synthetic fibers

PossibleMicroplastics from synthetic fiber shedding

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 barrier (fluorinated coating chemistry unknown), Azo dyes in synthetic fibers, Microplastics from synthetic fiber shedding and Coating adhesion and leaching as barrier degrades on the Thinx and not on the Modibodi.
  • The Modibodi is organic cotton blend with water-resistant coating where the Thinx is Nylon, spandex, cotton blend with waterproof barrier layer, 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 55% 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