Many people toss eggshells without realizing their benefits. Surprisingly, eggshells are “one of the most affordable and efficient natural sources of calcium you can find.” They are about 95% calcium carbonate, plus small amounts of magnesium, potassium, zinc, and iron—minerals the body uses to build strong bones, teeth, and nails. The shells also have a tough outer layer and two inner membranes rich in keratin proteins, which help protect against bacteria.

Eggshells can be a low-cost, sustainable calcium source for those who struggle to get enough through diet. “There’s no need to buy expensive eggshell powder from the store—making it at home is incredibly easy.” Studies even suggest calcium from eggshells may be absorbed better than synthetic supplements.

Health benefits include supporting bone strength, lowering osteoporosis risk, promoting collagen production, and strengthening teeth. Research notes that people consuming eggshell membrane powder showed “improvements in bone density,” while the membranes also contain collagen, essential for skin elasticity and joint flexibility. Finely ground eggshell powder can strengthen tooth enamel and is used in some natural toothpastes.

Precautions are important. Never swallow large pieces, as they can injure your throat, and always boil eggshells first to kill bacteria like Salmonella. Trace heavy metals are generally lower than in alternatives like oyster shells, making properly prepared eggshells safer.

While not a cure, eggshells can “support overall health in several indirect ways.” Always consult a healthcare professional before using them as a supplement, especially if you have health conditions.