It’s important to understand that this is completely normal and nothing to worry about.

Have you ever wondered why your underwear sometimes appears to have bleach stains? Many women have, and this question has sparked much discussion online.

Surprisingly, these patches have nothing to do with your washing machine. Instead, they are caused by the natural pH levels of the vagina.

These patches indicate a healthy vagina. pH levels measure the acidity or alkalinity of a substance, and as one informative Twitter post explains:

“Now that everyone is aware, it’s completely normal to discover lighter patches in a woman’s underwear or knickers due to the acidic nature of the vagina, with a pH range of 3.8-4.5. So, I suppose it’s time to abandon the notion of it being a result of poor hygiene. In fact, a healthy vagina is one that can bleach the fabric.“

Dr. Vanessa MacKay of the Royal College of Obstetricians and Gynaecologists clarifies: “The vagina has a self-cleaning mechanism through natural secretions. It contains beneficial bacteria that serve to protect it.”

The National Institutes of Health reports that the usual vaginal pH ranges from 3.8 to 5.0, making it moderately acidic compared to the neutral pH level of 7.

Dr. MacKay also notes that clear or white vaginal discharge is normal and healthy, and that disrupting this natural balance can lead to infections.