Your scalp is not supposed to be sterile. Explore the ecosystem beneath your hair, the emerging science, and the limits of microbiome claims.

Iron and vitamin D can belong in a hair-loss investigation, especially with diffuse shedding, but deficiencies should be tested and interpreted in the context of your health."

Dandruff is not caused by poor hygiene. Flakes can reflect subtle inflammatory activity within the scalp, which is why supportive care should focus on the skin—not shame or aggressive scraping.

Lavender may interact with hormone-related pathways under some conditions, but current evidence does not show that typical use routinely causes harmful hormonal disruption in adult women.