Rice water is like having gold in your home… but few people know how to use it.
See the first comment 
That statement is a common health-and-beauty claim. Rice water can be useful in some situations, but it’s not a miracle ingredient.
What rice water is:
Water left after soaking or boiling rice. It contains small amounts of starch, amino acids, vitamins, and minerals that leach out of the rice.
Common uses and what the evidence says:
- Hair care: Some people use rice water as a hair rinse, believing it improves smoothness and reduces friction between strands. There is limited scientific evidence suggesting certain compounds in rice water may temporarily improve hair feel and manageability, but claims of dramatic hair growth are not well proven.
- Skin care: Rice water may have a soothing effect on irritated skin for some people and is used in various cosmetic traditions. However, evidence for major skin benefits is limited.
- Gardening: Diluted rice water can add small amounts of nutrients and organic matter to soil, but it is not a substitute for proper fertilizer.
- Cooking: It can sometimes be reused in soups, broths, or doughs to reduce waste.
Things to watch out for:
- Rice water spoils quickly. Refrigerate it and use it within a day or two.
- Fermented rice water may cause scalp or skin irritation in some people.
- Excessive use on hair can leave buildup and make hair feel stiff or dry.
So rice water isn’t exactly “gold,” but it is a versatile household byproduct that some people find useful for hair care, skin care, gardening, and cooking. If you’re interested in a specific use, I can explain how to prepare and use it safely.