Alum, or potassium alum, is a naturally occurring mineral compound with various uses, including as a home remedy for hair care. While there are anecdotal claims about the benefits of applying alum to the hair, scientific evidence to support these claims is limited.
Alum has astringent properties, which means it can help to tighten the skin and close pores. When applied to the scalp, alum may help to reduce excess oiliness and unclog pores, which could potentially contribute to healthier hair follicles
Some people believe that alum can help to detoxify the hair and remove impurities and toxins. Applying alum to the hair may help to remove product buildup and environmental pollutants, leaving the hair feeling clean and refreshed.