I'll copy my post from this thread:
http://www.bluelight.ru/vb/threads/704425-Is-14-to-young-to-be-taking-Shrooms-LSD
"hey man!
I'm 15 and I first started experimenting with psychedelics when I was 14. Mushrooms were my first experience, and it was absolutely wonderful - truly a life-changing experience. However, I had the perfect set and setting. I didnt know enough about them to be scared (I thought it was going to be like in the movies where you prance around on daisies and shoot leprechauns haha), so I was very excited and didn't have any apprehensions. I was in my room alone at night with soft music playing. If I had done more research and discovered the horror of bad trips, my experience might have been wrought with anxiety and it wouldn't have been as successful...I find that one of the most important parts of having a good trip is letting the drug into your psyche - if you resist it, it might not result in a bad trip persay, but it definitely wont be as pleasant as an experience. It will probably be stressful.
And you have to prepare yourself for the experience that bad trips really suck, dude. like, really fucking suck. I've only had two - one on salvia (my first and only time with salvia, thank god it only lasted for about 10 minutes) and one with mushrooms. I've never tried acid and I'd recommend trying mushrooms before acid because bad trips on acid can take you much further down the rabbit hole, so I hear (you can have a psychotic break and end up in the hospital - I've never heard of that happening on mushrooms)
anyways, it sounds like you have some experience already - morning glory seeds are generally much gentler than more intense tryptamines like mushrooms, but they are a good intro to the world of psychedelic experiences. It's ultimately your call!
I have trouble believing that psilocybin causes any issues with a developing brain, but I'm no scientist. I remember seeing that Sacred Science documentary where a kid our age talks about how he first used ayahuasca when he was 6, and he's an incredibly intelligent and eloquent young man...go figure. Psychedelics have given me a lot of things, but they have taken away from my life as well. A truly transcendent ego-dissolving psychedelic experience is life-changing. You witness a complete uprooting of everything you held to be common knowledge, and that can change your outlook on life significantly. Since I started messing with psychedelics, I've had trouble feeling motivated to do schoolwork, and I don't feel as much connection to a lot of my peers. I also reject a lot of things that my family and teachers tell me, and I question everything. You could write this off as typical adolescent behavior, but I firmly believe that there's a deeper underlying part of me that has been changed by psychedelics and makes it difficult for me to behave like a normal 15-year-old. Beware."