SAN ANTONIO- It's black, gritty and even cringe-worthy for some, but charcoal detox drinks are growing in popularity despite.

At juice bars like San Antonio's Pure Juice, it comes in a glass filled to the brim with alkaline water, lemon, agave and activated charcoal. The drink is also known as "Vamp."

"First time I came in I wanted to try something different with my health," Joseph Millhouse, a faithful juicer, said. "That didn't really look too appetizing really, but when I tried it out it really tasted more sweet."

Juices like it, made with activated charcoal, promise sweet health benefits as well. It's one reason Lawrence Fields, with Pure Juice, said it's flying off shelves quickly.

"It's great for if you have any gastrointestinal issues, it absorbs all of that in one drink," Fields said. "It's also blended with lemon so that helps with the acidity in your stomach as well as detoxing the body, cutting your appetite."

Activated charcoal is nothing like the charcoal people grill with. It's a form of carbon processed to have small pores that absorb toxins in the body.

For some, it cuts cholesterol numbers down too, Nutritionist Amber Fischer with Balanced Health Healing Center, said.

"It's not a stand-alone, it shouldn't be something that you turn to as a miracle," Fischer said. "Is it going to make you lose weight? No. In order to lose weight and become more healthy, you really have to focus on the nutrition part of it."

Knowing when and how to include activated charcoal juice into your diet is vital as well, Fischer said. She advised it be consumed either two hours before or after a meal, to avoid it from absorbing nutrients.

"It can also bind to medications," Fischer said. "So if you do take any medications for your cholesterol or for diabetes or birth control it's possible it could bind to those things and reduce its absorptions in your body."

Fischer said activated charcoal is overall safe, but can cause side effects like constipation, diarrhea and in rare cases, intestinal blockages. Since the liver is the body's main detoxing organ, the nutritionist stressed the importance of supporting it by eating foods that help clean it out and by avoiding smoking and drinking.

"You can't just take your activated charcoal drink and expect to get the results of a detox," Fischer said. "You have to also pair it with a lifestyle that includes not doing these things that are harmful or make your liver sluggish."