The present invention relates to therapeutic, cosmetic, and nutraceutical applications for eggshell membrane, processed eggshell membrane preparations and eggshell membrane isolates. The invention is directed to treating a mammal that will benefit from the administration of naturally occurring material found in eggshell membrane, processed eggshell membrane, eggshell membrane isolates and combinations thereof by administering to the mammal a composition containing eggshell membrane, processed eggshell membrane, eggshell membrane isolates and combinations thereof, alone or in combination with other active ingredients.