An anarchist community cannot produce insulin - for the very same reason a capitalist or fascist community cannot. When we're talking about industrialized production, we are talking about things a whole lot bigger than merely communities. Simply focusing on community is myopic - a more relevant question would be, "How can an anarchist factory produce insulin (and other medicines)?" It's already a question far more grounded in what already exists.

Also, there is no such thing as "leaderless" organization, and there is no such thing as "leaderless" anarchism.