Okay, first there’s no Special K in Ecstasy. Not sure where you picked that one up from.
K is Ketamine 2-(2-Chlorophenyl1)-(methylamino)-cyclohexanone hydrochloride, which is, yes, a veterinary tranquilizer. It is a powerful dissociative (Cyclohexamine) drug (same class as PCP). Not a party drug, kids. Probably won’t make you too social. May make you forget that you do indeed have a body.
As with PCP, addiction has been known to occur, but not on the scale of heroin or cocaine. Some get hooked, some don’t. Also note that effects of ketamine are far different than PCP, even though they’re in the same class of drugs.
Ketamine has been linked to a type of brain damage known as NMDA Antagonist Neurotoxicity, but only if used repeatedly in large doses. (See http://www.lycaeum.org/drugs/Cyclohexamines/dissociative.brain.damage.html)) Also see the parent directory of that file for more info on Cyclohexamines. Ketamine is currently not tested for in normal piss tests.
On to Ecstasy, or MDMA 3,4-methylenedioxy-n-methylamphetamine, a methylated amphetamine. As to effects, it’s something like LSD with a twist of amphetamine, from what I’ve heard. Note that MDMA contains neither of those two substances, though you could get the LSD/amphetamine mix in a pill claimed as ecstasy. MDMA is a very difficult and expensive synthesis; that’s why you often see simpler, cheaper drugs substituted for it.
Addiction potential is low to moderate. Certainly much higher if you’re getting amphetamine in your pills on a regular basis.
I’m not sure if pure MDMA will show up as an amphetamine on a drug test, but even if it does, it’ll be out of your system in 3-4 days.
MDMA has been linked to serotonergic
neurotransmitter damage, though not permanent. Things in the brain return to normal within a year or so of cessation of the drug.
So these two drugs can be said to pose some risk, though not a HUGE risk. I wouldn’t recommend them, though. Personally I’ve never tried either (though I have dropped my fair share of acid).
I’d just stick with herb. It’s safer. 