Accidentally or on purpose? This whole shaking your peptides is a myth that has super fast runner legs. The truth is you can shake them and they will be just fine. Maybe if you put them in a paint can shaker we might see a problem (would be worth an experiment), but just shaking it like you'd shake a polaroid picture won't harm them.
HOWEVER....there are a few exceptions. Off the top of my head, AOD-9604 doesn't play nice. Don't shake that one. ARA-290 can be sensitive. Tesa has been odd at times. There might be a few others, so just out of habit I don't actively shake them. I just roll them around in my hands.