While eggshells are indeed rich in calcium carbonate (about 95% of their composition)—and have been used traditionally in some cultures as a calcium supplement—consuming them at home, even when boiled and ground, carries significant health risks that outweigh potential benefits.
Here’s what you need to know before considering this practice.
 Key Risks of Eating Eggshells
1. Salmonella Contamination
- Eggshells can harbor Salmonella bacteria, even if the inside of the egg is clean.
- Boiling may not fully sterilize the shell’s porous surface, especially if done briefly.
- Symptoms of salmonellosis: fever, diarrhea, abdominal cramps—especially dangerous for older adults, pregnant women, and those with weakened immunity.
2. Physical Injury from Sharp Fragments
- Even finely ground eggshells can retain microscopic sharp edges.
- These may irritate or scratch the esophagus, stomach lining, or intestines, potentially causing internal micro-tears or inflammation.
3. Heavy Metal Contamination
- Eggshells can absorb environmental toxins like lead, cadmium, or arsenic from soil, feed, or water—depending on how the hens were raised.
- Home preparation offers no way to test for or remove these contaminants.
