It may be better than having no epinephrine at hand. But other than that, there are a lot of problems: How sure are you that it will work when you need it? Can

It may be better than having no epinephrine at hand. But other than that, there are a lot of problems: How sure are you that it will work when you need it? Can you fill the syringe cleanly enough? Will the epinephrine in the syringe degrade, or worse, develop a bacterial growth? It may be a better Idea to look into a syringe+vial combination on hand, prescribed by a doctor. Less convenient, and you need to learn how to use it (and preferably teach those close to you), but this may be a whole lot safer. The downside of course is the problem of self-administration when in anaphylactic shock.