If you’ve paid a little extra for healthy food or even produced it yourself, you know the value of using up every last bit. Many of my recipes rely on eggs as a healthy protein source, but have you ever thought about holding on to those eggshells?

And I’m not just talking about throwing them into the compost pile!

The Incredible, Edible… Eggshell Powder?

The egg is a pretty incredible little package. Versatile, protein-packed, and full of nutrition (especially if they’re free-range). Eggs are high in:

• Riboflavin
• Thiamin
• Phosphorus
• Folate
• Iron
• Selenium
• Zinc
• Vitamins A, D, E, B6, and B12

Eggs are also a complete protein because they have all 9 essential amino acids. Unlike the amino acids found in nuts and beans, animal protein sources are better absorbed by our bodies.

Benefits of Eggshell

But what about the shell? It’s about 90% calcium carbonate — the same material in our nails, teeth, and bones. We need calcium intake for proper bone density, heart health, our nervous system, and other functions.

As we age our body needs extra calcium to keep up and a calcium deficiency can contribute to issues like osteoporosis. For strong bones and overall health, it’s important to balance our daily calcium with magnesium, vitamin d3, and vitamin k2 intake.

If you’re trying to get calcium without dairy or take a calcium supplement (which I don’t necessarily recommend), “eating” your eggshells may be for you! A 2003 review found that eggshells are absorbed just as well or even better than regular calcium supplements.

How to Make (Edible) Eggshell Calcium Powder

Here’s how to transform your eggshells into a high-quality, food-derived supplement:

1. Save your chicken eggshells (you can do this right in the egg carton if you like). Surprisingly, they don’t smell. You can leave the eggshell membrane in the shells but be sure to rinse out any egg white.
2. Once you have some eggshells, sterilize them for a few minutes in boiling water.
3. Strain the shells and spread them out on a baking sheet to dry overnight.
4. Bake eggshells at a low temperature in the oven for about 10 minutes to dry them out. For efficiency’s sake, you can put them in the oven when you’re going to cook or bake anyway. I just take them out before the temperature gets too high.
5. Grind the eggshells to a very fine powder. A coffee grinder or spice grinder works best. You can also use a mortar and pestle. If you want larger pieces for the garden, then a food processor works well.
6. Store in an airtight container (like a mason jar) in a cool, dry cupboard.

Using Eggshell Powder in Food

Add about ½ teaspoon eggshell powder per day to food for 400-500 mg of bioavailable calcium. You may notice a slightly gritty quality when added to certain foods. I like using the eggshell powder in smoothies or yogurt, and it’s undetectable in baked goods and heavier foods. Chia Seed Energy Bars or Breakfast Burgers work well for this.

You can also put some crushed eggshells in with vegetables and bones while making bone broth. A small splash of vinegar helps break down the nutrients in the ingredients even better.

Eggshells in the Garden

Not up for eating your eggshells? Calcium is equally important for the garden! Calcium-deficient soil causes slow growth and diseases like blossom end rot (when tomatoes, squash, or peppers turn black on one end). Here’s how to use ground eggshells in the garden.

• Soil Amendment – The key to using eggshells in the garden is to give it time. Plants take calcium in through the roots. You’ll want to work the eggshell powder deep into the soil in the fall or early spring to allow them to dissolve. Make sure the powder is finely ground (not in large pieces) or it won’t work.
• Pest Deterrent – Crush leftover eggshells into small shards and sprinkle them over garden soil. Slugs and other garden pests will find the sharp shells inhospitable and look for greener pastures (hopefully!).

Seed Starters from Eggshells

While peat pots and seed starter kits aren’t expensive, there’s an even simpler method. Half of an eggshell makes the perfect renewable seed planter!

• Save the eggs that break more or less evenly, wash them out, and poke a small hole in the bottom.
• Fill with seed starting soil and plant your seeds as usual.
• Move the grown seedlings into the garden right in the shell!

Sidenote: My kids love drawing faces on the eggshells so the seedlings look like “hair.” Thank you Pinterest!

This post has a handy chart to look up planting times for your zone. But on to another great use for eggshells…

The DIY Beauty Booster

Of the many DIY uses for eggshell powder, here are some I’ve tried:

• Facial – Mix 2 tablespoons of finely powdered eggshell into an egg white. Gently apply the paste as a natural facial mask, letting it dry for 10-20 minutes. Wash off with warm water and a circular motion to exfoliate. I really notice firmer, smoother skin after this treatment!
• Homemade Toothpaste – Use eggshell powder in place of the calcium powder in my DIY remineralizing toothpaste recipe. It will both whiten and remineralize. It also works as a calcium powder replacement in any of my homemade toothpaste or tooth powder recipes.
• Body Scrub – Add several tablespoons to a homemade body scrub recipe for a double-duty exfoliant that’s also the perfect prep for a summer pedicure!
• First Aid – Red, irritated skin, or bug bites? Let crushed eggshells soften in a few tablespoons of apple cider vinegar. Once it liquifies, apply with a cotton ball for a soothing effect.

Can Dogs Eat Eggshells?

Eggshells are a good calcium source for our canine friends too. You can sprinkle some finely ground eggshell powder over their dog food as a supplement. Just like us though dogs need a balance of nutrients, so it’s best not to overdo it. Some pet experts recommend feeding dogs boiled eggs that have been cut into pieces instead.

Talk to your vet and see if they recommend the extra calcium in your dog’s situation.

What do you think? Would you ever eat your eggshells? Are there other ways you’ve found to use them?

Sources:

1. Cleveland Clinic. (2021). Amino acids.
2. Enroth, C. (2018). Using eggshells in the garden and compost.
3. Joy, H. (2020). Can dogs eat eggs?
4. Rovenský, J., Stancíková, M., Masaryk, P., Svík, K., & Istok, R. (2003). Eggshell calcium in the prevention and treatment of osteoporosis. International journal of clinical pharmacology research, 23(2-3), 83–92.
5. Self Nutrition Data. (2018). Eggshell 1/2 tsp.
6. University of Wisconsin Dept of Medicine. (n.d.). Why is Calcium Important.