The claim “When the knee runs out of collagen, eggshell is the solution” is a popular social media claim, but it is not proven that eating eggshells can rebuild knee cartilage or restore lost collagen.
Eggshells contain mostly calcium carbonate and the inner eggshell membrane contains proteins, including collagen-related compounds. Some studies have looked at eggshell membrane supplements for joint comfort, but this is different from using homemade eggshell powder, and the evidence is not strong enough to say it can “repair” knees or reverse arthritis.
What actually supports knee and joint health
- Adequate protein: Provides amino acids needed for maintaining muscles and connective tissues.
- Vitamin C–rich foods: Vitamin C is required for the body’s normal collagen production.
- Vitamin D and calcium: Support bone health when intake or levels are inadequate.
- Strength training: Builds muscles that help support and protect the knees.
- Healthy weight management: Can reduce stress on weight-bearing joints.
- Physical therapy: Can improve strength, mobility, and pain in many knee conditions.
If considering eggshell products
Be cautious:
- Raw eggshells may carry bacteria unless properly cleaned and processed.
- Homemade eggshell powder can have uncertain particle size and dosage.
- People with kidney disease or calcium-related conditions should ask a healthcare professional before adding calcium supplements.
Persistent knee pain, swelling, locking, or reduced ability to walk should be evaluated to determine the cause—such as osteoarthritis, injury, inflammation, or another condition—rather than relying on a single ingredient.
