The JWHs are pretty crazy and I generally advise people to steer clear of them in anything other than a very small sample dose (if that).
I had not done any drugs over the past 3-4 months other than weed on a handful of occasions, since I started taking an SSRI antidepressant. I missed getting high and was intrigued by what I read about the JWHs (especially since it sounded like it wouldn't interact badly with the SSRI) and ended up ordering a gram of JWH-018. I started out with little baby hits (pile about the size of a 0 on a credit card) vaped off of foil, always waiting at least 10-15 minutes between hits -- I found it pretty easy to maintain a comfortable high without getting into "the fear" territory or whatever. I did accidentally take too big a hit once early on, and basically ended up horizontal with my eyes closed for half an hour -- unpleasant but manageable. The dosage is pretty manageable but tolerance definitely creeps up quickly; within about 3 days of regular use I was smoking 10mg hits every couple of hours and getting high as FUCK. If you think of cannabis as beer, JWH is roughly like drinking shots of hard liquor -- the experience doesn't have the same "ceiling" or rolloff point of beer / cannabis.
That first gram lasted about a week and a half, I ordered two more grams of 018 and two grams of 073, most o which was gone in a little over two weeks. Over that time I was smoking heavily all day every day, getting severe couch lock, excellent body high, OEV (like pulsing lights/auras at the edges of vision). I tried typing a log of the experience which quickly became nearly incomprehensible (granted, in a way which I find entertaining but would not attempt to translate to others). Basically I felt like a character in such as a Redman song, where he's talking about being so high he writes his mama bad checks in crayon or something. I was responsible for such antics as calling the pizza delivery place to ask about my order (which had been delivered 20 minutes previously and I had already eaten two pieces of it). I did not get behind the wheel of a car or operate heavy machinery, nor did I have any problems interacting with friends or random strangers. Basically (and granted, I AM an Experienced Drug User (TM)) I felt like that even though I was absolutely going at it like a cannabinoid crack friend I was still basically as functional as a heavy heavy weed stupor, I wasn't going to flip out and run out into the street naked or anything.
I guess I finally got a proper overdose about two weeks into that second batch; I'd been up most of the night smoking JWH (and eating tiny pinches once in a while) when I started to get these really awful stomach cramps. I threw up a couple of times and for a couple of hours I had a knot in my stomach that felt like I'd been punched in the gut. I went to lie down for a couple of hours, tried to drink plenty of water and eat some saltines, I know I had a little bit of a panic attack but I chatted with my friend on IM a little bit, told her I felt really stressed and uncomfortable and stomach achy and she was sweet and sympathetic and that definitely helped me relax (and again, this was partly manageable because I am not a drug novice and have had my share of nausea / stomach cramps -- I shudder to imagine the clueless teenager who gets hold of a sack of Spice XXXXL K12 or whatever and does epic waterpipe rips for 15 minutes before landing straight into several hours of oh mother fuck it makes me so angry that this shit is legal and weed is not.
That was about a week ago and ever since then, I've barely been using JWH, only really using because when I DON'T use it, my appetite is all messed up (sort of like when you stop smoking weed after chiefing it every day for a good stretch) and I get some muscle soreness and minor twitching, especially in the back of the shoulders. Also, after that heavy run on the JWH, my sleep schedule is still messed up; unless I've been smoking JWH that night, I have a hard time getting to sleep before around 3AM, and I'm 100% bright awake at 8-9AM.
JWH has its fun/interesting side but I seriously question the potential health risks especially of significant use. My residual soreness and nausea do feel improved on a day to day basis, but at this rate I'd estimate it'll be at least a couple of weeks before my metabolism (hopefully) feels fully reset.
Please be careful around these chemicals.