There is an additional problem caused by the prohibition (illegality) of cannabis...

Cannabis which you grow yourself or which was grown by someone you know will be OK But it's important to realise that most cannabis is supplied by an illegal economy and the so called "black market" weed and hash may be very contaminated.

In the UK this not only means "Soap bar" (which should always be avoided anyway), but it may well apply to any imported hash or weed. Also the problem of contamination isn't limited to the "grit weed" which has recently become so widespread.

Eating/drinking cannabis can be extremely dangerous due to the presence of chemical contaminants and/or pathogens (microbes), given the high possibility of adulterants in imported cannabis, you should really think twice before using a non-smoking method.

There is no reliable way to clean contaminated cannabis, for example if your grass comes from sprayed crops there's nothing you can do about that. Crops in the producer countries are being sprayed by the US government with cancer causing herbicides as a part of the UN plan to eradicate cannabis from the world by.... 2008. Seriously, that was the plan.

Cooking at a high temperature will kill most pathogens, but maybe not all of them - if you crank up you're oven too high you'll nail the THC too... not to mention burning the brownies!

At the very least, NEVER eat street cannabis which hasn't been cooked, e.g., hash which has just been crumbled up and sprinkled on a sandwich; you'll probably be OK, but you might just end up with the runs - you could conceivably end up with hepatitis.

The obvious answer to all this is the end of Prohibition and the introduction of quality controls, but meanwhile please be careful regarding the eating / drinking method. It's generally good advice not to buy cannabis supplied by organised crime, get to know someone who grows at home.

Note to governments and the UNODC:
All of the above problems are caused directly and solely by prohibition, they need not be happening and they are happening because of your policies. If cannabis were legal and properly regulated, consuming cannabis in food or drink would be the safest way to consume it.