Earlier quoted context omitted.
I commented about using any drug entails some finite risk of bad effects. The apparently common belief that "designer drugs" shouldn't be "illegal" is certainly not supported by the article. I can see your line of thinking: X has risks, X should not be done, thus make X illegal and X will not be done and the risk will no longer exist. But that's not the way the world works. Making X illegal does not prevent X being d…
There's also the unspoken "X has risks, and I don't want to do X, therefore X should be illegal". I ride motorcycles. I have friends and family involved in scuba diving, paragliding, football, rock climbing, hell - even horse riding. _All_ of those activities have "well known risks of serious injury or death" associated with them, and each of them I've heard recent stories of death in the extended circles of my famil…
Point is with motorcycles, cars, scuba, yes, even horses, the risks are more or less known and probability of various outcomes, including harm, can be reasoned about.
With drugs the estimation of probable outcomes is orders of magnitude more difficult to compute. To say it again, all drugs have numerous effects which vary greatly among recipients, and even for established agents most drug effects have received little or no study. However we do have a systematic track record of the AEs encountered, and after millions of cases we have a pretty good idea of how to use the agent safely.
Legal status notwithstanding, a drug with potent enough effects to be interesting is asymptotically guaranteed to have adverse effects in some members of the population of potential users. It means effects of a new and arcane product are no more than a total crap shoot.
Since even low frequencies of AEs may disqualify a drug as "safe", regulatory bodies require testing sufficiently large number of subjects under tightly controlled conditions to show evidence that it's safe enough to justify its proposed uses.
Without such study it is impossible to evaluate the use of an unvetted drug in the same way as riding a motorcycle. The information about benefits and risks is just not known. There is simply no basis for making a rational decision.
As a clinician and scientist questions of prohibition are largely beside the point. People will continue to do stupid things laws aside. However, laws/rules exist as a benchmark, and optimally serve as a statement of our communal ethical stance. Not that it's going to stop people who are determined to use a prohibited drug anyway, but maybe it supports restraint in some people who are "on the edge".
In respect to designer drugs, I'm very reluctant to say let's have no regulations at all, that anything goes, because logically lack of safety data leaves us to assume the risk of harm is significant. The burden of proof ought to be on the shoulders of those who assert use of the drugs is just harmless diversion.