Caffeine and Marijuana: What Happens When They Mix?

Research on the interaction between caffeine and marijuana is still in the early stages, but so far, it seems that consuming the two together may produce different effects than using them separately.

Caffeine generally acts as a stimulant, while marijuana can act as either a stimulant or a depressant. In other words, using caffeine tends to energize most people. The effects of marijuana can vary, but many people use it to feel more relaxed.

It may seem possible, then, that caffeine might cancel out the effects of marijuana, or vice versa. For example, maybe smoking a little weed could help counteract coffee jitters. But so far, there's no evidence to support that the two counteract each other in any way.

While there's no evidence to suggest that marijuana and caffeine simply cancel each other out, two animal studies suggest that mixing the two may enhance some of marijuana's effects.

A different 'high'

A 2014 study looked at squirrel monkeys who had been given THC, the compound in marijuana that produces the high. The monkeys had the option to keep receiving more THC.

Researchers then gave them different doses of MSX-3, which produces effects similar to those of caffeine. When given low doses of MSX-3, the monkeys gave themselves less THC. But at high doses, the monkeys gave themselves more THC.

This suggests that low levels of caffeine may enhance your high so you don't use as much. But high levels of caffeine could affect your high in the opposite way, leading you to use more marijuana.

More research as needed, as this small study was conducted only on animals, not humans.

Memory impairment

Caffeine helps many people feel more alert. You might drink coffee, tea, or energy drinks every morning to help you wake up, or just to help increase your concentration when you feel tired or less focused than usual.

Some people also find caffeine helps improve working memory. Marijuana, on the other hand, is known for its less desirable effect on memory. Again, you'd think the two would balance each other out, but that doesn't seem to be the case.

A 2012 study looking at how a combination of caffeine and THC affected memory in rats. The results suggest that a combination of caffeine and a low dose of THC seemed to impair working memory more than a higher dose of THC would on its own.

Remember, this study was only done using rats, so its unclear how these results translate in humans. Still, it does suggest that caffeine may increase the effects of THC.

So far, there haven't been any reported cases of extreme risks or side effects of combining caffeine and marijuana. But that doesn't mean they don't exist.

Plus, people can have varying reactions to both caffeine and marijuana. If you do try mixing the two, make sure you first understand how your body reacts to each one individually. If you're sensitive to marijuana, for example, combining it with caffeine might result in an unpleasantly strong high.

If you do decide to mix marijauna and caffeine, follow these tips to help you avoid a bad reaction:

• Start small. Start with small amounts of both, less than you would typically consume of each individually.
• Go slow. Give your body plenty of time (at least 30 minutes) to adjust to the combination before having more of either substance.
• Pay attention to usage. It might sound like overkill, but it's easy to lose track of how much caffeine or marijuana you've had, especially when mixing the two.

There are serious side effects that can come from ingesting very high doses of caffeine, from high blood pressure to rapid heart rate. There have also been deaths related to ingesting large amounts of caffeine, though researchers noted that the deceased took caffeine pills or powder, not caffeinated drinks.

Above all, make sure to listen to your body and mind. If you experience unusual symptoms after mixing the two, reach out to a healthcare provider for guidance. You likely aren't in any great danger, but the combination of caffeine's heart-racing effects and marijuana's tendency to cause anxiety in some people can be a recipe for panic.

It's unclear if mixing caffeine and marijuana has any long-term effects. But remember, an animal study found that consuming THC with large amounts of a substance that mimics the effects of caffeine may minimize marijuana's effects. This might lead you to use more marijuana than you usually would.

Over time, repeatedly using increasing amounts of marijuana may lead to developing a substance use disorder.

If you regularly mix caffeine and marijuana, keep an eye out for these signs of a substance use disorder:

• developing a tolerance to marijuana, requiring you to use more to achieve the same effects
• continuing to use marijuana despite not wanting to or encountering bad effects
• spending a lot of time thinking about using marijuana
• paying close attention to maintaining a constant supply of marijuana
• missing out on important work or school events due to marijuana use

Experts still aren't certain of the full extent of the interaction between caffeine and marijuana in humans. But the effects likely vary from person to person. Your personal reaction and tolerance to each substance may also play a role in how the two interact.

Because existing research does suggest caffeine can enhance a marijuana high, you may want to use caution when combining caffeine and marijuana — whether it's coffee and weed or black tea and edible gummies —especially until you know how they affect your system.