Sarah Silverman brought marijuana to Monday night's Emmy Awards in the form of a vaporizer. If you're scratching your head wondering what the heck liquid pot is, you're not alone. Here's how it works—and what it does to your body and mind.

You've probably heard by now that Sarah Silverman brought pot with her to Monday night's Emmy Awards, but for those not in-the-know, here's a recap: During an E! News "clutch cam" segment, the 43-year-old comedienne and actress revealed to Giuliana Rancic that in addition to gum and her phone, she was carrying a marijuana vaporizer. "This is my pot. It's liquid, um, pot," Silverman explained to a somewhat-shocked Rancic, who didn't seem to expect this particular accessory to be revealed. (Watch the awkward moment in this Vine video.)

If you're scratching your head wondering what the heck liquid pot is, you’re not alone. So we went to Shilpi Agarwal, MD, a board-certified family physician in Washington, DC, with our burning questions.

So, what is liquid pot?

It’s actually called “liquid THC.” The THC stands for tetrahydrocannabinol, which is the component in cannabis that gives it its psychoactive affects. The liquid can either be bought in cartridges or extracted from a marijuana plant (a method that can actually be dangerous—more on that later). The liquid then gets loaded into a vaporizer pen, like the one Silverman brought in her purse.

Why do people use vaporizer pens?

Frankly, many people use "vape" pens because it's easier to hide what it is they're really smoking. Like e-cigarettes, vape pens use a battery-powered heater to vaporize the THC liquid—so no fire, no smoke, and no smell. Dr. Agarwal notes that some people believe that vaping is healthier, but research shows that's probably not the case. Others say vape pens simply feel easier on the lungs—including Whoopi Goldberg, who wrote about her experience using one to treat her glaucoma on The Cannabist.

How does liquid THC affect the body?

It affects your body like other forms of cannabis: liquid THC causes an increased appetite, increased heart rate, dry mouth, and mood changes—some people experience a calming effect while others notice worsening anxiety, says Dr. Agarwal. Like smoking, it takes just a few minutes for liquid THC users to begin feeling its effects. (Edible forms take about a half hour to set in.)

Is it riskier than other types of marijuana?

It might be. NPR reports that while marijuana flowers contain up to 20% THC, these liquid concentrates may have up to 90% of the psychoactive ingredient. That means inexperienced pot smokers could faint or throw up if they take too much of it. Additionally, there have been reports of explosions when users attempt to extract the THC oil on their own using butane.

And like any other form of marijuana, liquid THC comes with its risks, Dr. Agarwal says. Those risks include extreme paranoia and psychosis (hearing voices, seeing things). Injuries can also happen when you’re under the influence, thanks to side effects like very slow reactions, difficulty concentrating, rapid heart rate, and vision changes.

Is it regulated?

There are no standards for the manufacture of liquid THC. That means when you buy a bottle, you can’t be 100% sure what’s in it. “What could be sold as liquid marijuana can very easily be mixed with other dangerous chemicals that can cause hallucinations, seizures, and even death, depending on the composition,” adds Dr. Agarwal.

Is it legal?

Using a vape pen to smoke marijuana is legal in Colorado and Washington state, where all recreational pot use is allowed. And if you’re a medical marijuana prescription holder in the state of California, then it’s legal to use it there, too. So as long as Silverman has a prescription from her doctor, she’s in the clear. That said, the federal government does classify marijuana use as illegal.

Leslie Barrie is a Staff Writer at Health.