Finding bleach spots on underwear isn’t always from cleaning accidents. There are a few surprising reasons this can happen.

**1. Cleaning Products**
A common cause is accidental contact with bleach during laundry or housework. Even small spills can leave stains. “Be careful when handling bleach and store it safely away from clothing.”

**2. Skincare and Hygiene Products**
Products like acne treatments or whitening creams often contain hydrogen peroxide or benzoyl peroxide. These can bleach fabric when they touch your skin or clothes. As the article notes, “These chemicals can unexpectedly bleach your clothing.”

**3. Vaginal Discharge and pH Levels**
Natural vaginal discharge can be acidic, especially during ovulation, and may cause light discoloration over time. This is normal and not harmful, but it can fade fabric.

**4. Sweat and Body Chemistry**
Perspiration mixed with body products or pH levels may also react with underwear fabric, leading to bleach-like patches.

**5. Fabric Sensitivity**
Some fabrics react more strongly to chemicals or pH changes. Choosing high-quality cotton can help reduce visible staining.

In most cases, bleach patches are harmless and linked to common chemical reactions, not actual bleach use.