It turns out there's truth in the old stoner adage, "weed before beer, you're in the clear".
With marijuana becoming legal in different parts of the world and more socially acceptable even in places where it's still illegal, it's likely that more people will try what's known as 'crossfading' - mixing alcohol and weed to get a different, stronger kind of high.
"Not everyone responds to alcohol and marijuana the same," Harvard Medical School marijuana researcher Scott Lukas told Vice magazine recently.
Prof Lukas has studied how the two popular drugs affect people when taken together - one had people drinking before toking, the other study reversing the order.
THC slows the body's ability to absorb alcohol, says Prof Lukas. This means if you toke first, any alcohol you drink afterwards isn't going to hit you as hard as it normally would - weed before beer, you're in the clear.
The reverse of this is best summed up in the phrase: "beer before grass, you're on your arse".
Alcohol takes longer to kick in than marijuana, and as regular drinkers know, can take a lot longer to wear off. Once alcohol is in your system, it boosts marijuana's effects by opening up your blood vessels, allowing more THC to be absorbed.
If too much is absorbed, it results in a phenomenon stoners refer to as 'greening out', which can involve feeling extremely dizzy, sweaty and nauseous. Vomiting is a common outcome.
Prof Lukas hopes to study whether vaping or eating cannabis instead of smoking it will increase or decrease the likelihood of 'greening out'.
As with other areas of life, common sense is key to avoiding bad outcomes - and remember the effects will be slightly different for everyone.
"If you're sitting alone in your bedroom and you've got pillows all around you, and you're well-hydrated, and the bed's not too far off the ground, the risk is low," Prof Lukas told Vice.