I am a 26 year old female and I am starting to get gray hair. Can thyroid problems cause gray hair?
Thyroid hormones (T4 and T3) directly affect hair follicles promoting hair growth and pigmentation. Melanin is the substance that defines hair color and thyroid hormones stimulate its production in the hair follicle. Low levels of circulating thyroid hormones would reduce melanin production and are a likely cause of early graying of hair.
