I don't think it would be possible to overdose on garlic, from a health standpoint anyway. Especially when it's fresh. I love cooking with it.
Once a year we make this tonic that has garlic, onions, hot peppers, horse radish, Bragg's cider vinegar and ginger. We put it all through a blender and make several batches, then store it in glass jars and take several spoonfuls when we're sick or when we're exposed to someone else's illness. It works great! Taste pretty hot, but it works.