Most people achieve ketosis--a flow state of enhanced performance that occurs when your body burns fat instead of carbohydrates--through a strict diet regimen that takes weeks. That's far too long for Geoff Woo and Michael Brandt, the founders of a startup called HVMN. They want to get you there instantly.

After leaving the Shark Tank stage with no offer for their supplement company Nootrobox in 2016, the two created a ketone ester drink they say gives you the strength, energy, and focus of being in ketosis for 5 hours. Ketone ester is essentially raw BHB (beta-hydroxybutyrate) ketone, a compound produced by the liver from fatty acids during periods of low food intake.​

In the video above, two Inc. staffers, Chris Beier and Kevin Ryan, tried HVMN ketone for themselves. They found it less than pleasant to drink. "If you liquidated plastic and cooled it down but kept it in its liquid state, that's what it tasted like," says Chris Beier. Both were also turned off by its price--the drink costs a whopping $33 per bottle.

In their nonscientific test, the two did see some positive effects from HVMN (pronounced "human"), which the company says is a "validated superfuel that can be used to improve training, recovery, and performance." Some experts doubt the drink's usefulness, however.

"It's a very misleading and unnecessary supplement," says Ben Sit, a registered dietitian and founder and president of Evolved Sport and Nutrition, a dietary and nutrition-focused lifestyle management group.

According to Sit, the ester will skyrocket your ketone bodies to anywhere from 4-6 mmol/L depending how how much you drink, which is considered a high state of ketosis. But he cautions that unless you are adapted to the ketone esters and following a strict dietary intake of proteins and carbohydrates, your body will dispose of the supplements quickly, leaving you with little benefit.

"I don't think it could help the brain perform at an increased capacity," Sit says. "What I think it could do is maintain someone's blood sugar levels so the brain is more consistent," meaning that you won't feel the usual spikes and dips in energy that you would after eating a large meal. You also shouldn't look to the drink as a way to get a quick boost, he adds. Instead, you're better off focusing on improving your diet to achieve the desired results.

Other experts have a more positive view of the use of supplements like HVMN, but also give caveats. Kristen Mancinelli, a registered dietitian and author of The Ketogenic Diet, says you need to be aware of how your body reacts to being in a state of ketosis. "I would not try ketones for the first time before a presentation," she warns. "You don't know how they're going to affect you, and one of the main side effects is diarrhea, bloating, and GI discomfort." She says they could give you an extra boost as a complement to a ketogenic diet, when your ketone levels are already high, but recommends you start small.

Our testers suspected HVMN may also have a placebo effect, so you might experience some benefit regardless of the actual physiological impact. Plus, who knows? Maybe you'll find you like the taste of liquefied plastic.