Certified Organic: Organic eggs must come from chickens that live in a cage-free environment, have access to the outdoors (even if it is a very small space), and are fed an organic vegetarian diet free of animal by-products, commercial fertilizers, pesticides, and genetically engineered food. Due to the high cost of obtaining organic certification, organic eggs can cost about $4 a dozen.
Free-Range or Free Roaming: Unlike organic eggs which must undergo a third party verification process, there are no set standards to qualify eggs as free-range. Free-range means nothing more than that the hens were un-caged with at least some access to the outdoors. In theory, free-range eggs should be more nutritious because the chickens are outside absorbing Vitamin D from the sun and (as natural omnivores) eating insects for protein. But since the USDA has no certification process for free-range eggs, one has no way of knowing how much outdoor space hens were given or if they ever even took advantage of the opportunity to go outdoors. Free-range eggs can cost up to $5 a dozen.
Cage-Free: This label indicates that hens were un-caged, although most likely within a barn or warehouse. There is no guarantee that chickens had any access to the outdoors. This term is not regulated by the USDA and there is no certification process. Cage-free eggs average just over $3 a dozen.
Omega-3 Enriched/Enhanced: This label means hens were fed either fish oil or flaxseed. Since this label is unregulated, there is no way to know how much omega-3 is in these eggs. They average over $3 a dozen.
Certified Humane: To qualify for the Certified Humane label, egg producers must leave hens un-caged (although no outdoor time is required) and able to perform natural behaviors such as nesting, perching, and dust bathing. There are also requirements for stocking density and the number of perches and nesting boxes, but none regarding what they can be fed. About two-thirds of cage-free eggs carry the Certified Humane label. Compliance with Certified Humane standards are verified by a third-party.
Vegetarian-Fed: This label simply means the hens were raised on feed free of animal by-products. Eggs with this label are not commonly found in supermarkets.
Natural or Naturally Raised: Anyone can put this label on their product. There are no regulations for labeling eggs as natural.
Hormone Free: Another superfluous label. All eggs are hormone free since the practice of using hormones in poultry was banned in the 1960s.
Finally, although they average about 50 cents more than white eggs, brown eggs are not nutritionally any different. Eggshell color is determined by the type of chicken.
So, at the end of the day many egg labels don't give you a definitive answer about what is in that carton. A free-range egg from a local farm and a free-range egg from the chain supermarket down the street can be two very different eggs. If you are going to cough up the extra money for eggs, your best bet is to go with organic. They have fewer antibiotics and chemical residue and tend to have higher levels of omega-3 and vitamin E. Organic is a certified label so you are guaranteed that these egg producers have met set standards. Plus, these farmers tend to be more environmentally-conscientious.