And even heroin as a drug causes less physical harm in principle than stated - proper administration primarily results in constipation and very rarely organ damage. The primary danger come from improper intravenous drug use along with variable concentrations of drug due to buying from a black market, resulting in accidental overdose.

Khat is a funny one - didn't we already go through the racial disparities in prosecuting "crack" and "cocaine" differently? It's too bad the African Khat-using community didn't muster as much political muscle as the kratom community is.

Spoiler for anyone that doesn't want to click through to the first link: MDMA is apparently roughly the same in physical harm as marijuana, but rates lower on the dependence scale. I did not expect that, but then, I've never done MDMA.

That seems highly misleading. I think MDMA is far more physically dangerous than cannabis. Many people have directly died from irresponsible use of MDMA, but no one has (directly) died from any use of cannabis. MDMA can certainly be safe and beneficial if taken responsibility, but:

- Doses should generally be spaced at least 2 (many recommend 3) months apart.

- The minimum effective dose should be taken. Even a light overdose can create an uncomfortable, traumatizing, or even physically dangerous situation.

- Hydration and access to cool environments is important. Overhydration can also be a risk, so it's good to have access to electrolyte-laden drinks (Gatorade etc.). Overhydration, dehydration, and brain overheating are the leading causes of MDMA-related death.

- Supplements should be taken to reduce the inherent neurotoxicity even if you do all of the above things right. Some good examples on http://www.rollsafe.org.

It's true that dependence-wise, cannabis is probably worse, though. It's pretty hard to build a dependence on MDMA, as you'll likely only feel the uncomfortable stimulant effects (and other negative symptoms; this can lead to long-term or permanent neuroreceptor damage and dysfunction) if you take it on a weekly or daily basis.

No one has ever died directly from an MDMA overdose (as far as I know). Yes there have been indirect deaths usually from over-hydration (which causes the brain to swell, with or without MDMA), which usually happens in a rave/dance setting.

I'm sure there have been many indirect deaths from cannabis as well. Lung cancer, car crashes, falling down an elevator shaft, etc.

This is going to be true of any sufficiently powerful psychoactive substance.

If you completely ignore deaths for a moment, many report severe negative symptoms, lasting weeks or more, resulting from dehydration or overheating from MDMA. Overheating is also speculated by many researchers to be responsible for some of MDMA's neurodegenerative and neurotoxic effects.

You probably won't die due to MDMA, but if you're not careful you can certainly cause brain issues. And that makes it more physically dangerous than cannabis.

Perhaps. Personally if I drew the graph, I would put MDMA and cannabis closer together in terms of physical harm. I think they are dangerous in different ways and it's difficult to say which is more dangerous in absolute terms.

Like you say, if you are careful and informed, you can avoid lots of the dangers of MDMA with responsible use. It's difficult to smoke pot and not do some damage to your lungs, no matter how careful you are. Vaporizers not withstanding, but vaping was probably not considered in the graph.

I think one of the biggest problems with MDMA is that what you are getting is not always MDMA[1]

Better access to drug testing for consumers could help here.

[1] https://www.ecstasydata.org

I agree, but this isn't a problem with MDMA, but with illicit drugs in general. When you buy cannabis, LSD, cocaine, or anything else on the street, you have no way of knowing what's in it for sure unless you have a way to test it.

This is one of the big arguments for legalization / decriminalization. It won't be an issue with the MDMA these trial patients are receiving for example.

that's not a very accurate way of phrasing it. in some scales it's considered similar in abuse potential but that is extremely different than physical harm.

both are considered medium for abuse potential. cannabis is so non-toxic it doesn't even chart for physical harm. mdma is medium toxic, especially with sustained use.

Not according to the graph or the study. Source? Toxicity is not the only measure for physical harm.