I have picked liberty cap mushrooms. My experience is even if they are similar sized, each mushroom can have a different potency. Fresh picked or dried. I have eaten 100's and i have not heard of overdosing on them. Same with those truffles you get in Amsterdam I have not heard of test kits which measure the Psilocybin. Look at guides on the web to identify your shrooms aswell. Many look the same but can be totally different. psilocybin