Often times, people with milk allergies can tolerate ghee. This is because there is no lactose or casein in ghee when is properly made. This is true for me, dairy upsets my stomach and flares up my eczema. But I don't have any issues with ghee.
One nice thing about ghee is it has a long shelf life. After it can be kept in the cupboard for several months. You don't have to worry about it going rancid like butter. It will be semi-solid at room temperature but still soft enough to scoop out with a knife and spread onto food. It can be kept longer in the fridge but it will firm up and difficult to scoop out.
Ghee is perfect for high temperature cooking. It won't burn like butter because the milk solids are gone. It has a much higher smoke point than extra virgin olive oil so it's a better option for frying. When olive oil is heated past 350-375 free radicals are released and act as carcinogens when consumed.
It's much cheaper to make your own than to buy it. Ghee comes in tiny little bottles and is rather expensive at stores. Take a little time to melt some butter and save your money. When purchasing butter make sure it's organic from grass fed cows. Chemicals, antibiotics, and hormones are stored in fat, so factory farmed cows often have toxins in their milk.
Ghee from healthy cows will have a deep yellow color. This indicates that it is very nutrient dense. It also has vitamins A, D, E, and K, antioxidants, and butyric acid (anti-cancerous).
The saturated fat found in ghee is good for our heart, brain, bones, and immune system. Saturated fat actually raises HDL cholesterol and protects the heart. Calcium can't get into our bones without the help of saturated fat, so it can help prevent osteoporosis. Our brains need fat and cholesterol to function properly. Finally, saturated fats have antimicrobial, antifungal, and antiviral fatty acids that keep our immune system strong.
Sources Include: The Weston A. Price Foundation, Mary Enig, Sally Fallon, and Dr. Mercola.