If it feels like every time you open Instagram, a celebrity is promoting a new energy drink, you’re right. In December, Alex Cooper dropped Unwell Energy, while celebs like Dwayne “The Rock” Johnson and Logan Paul have been in the energy drink game for a few years. Now, Kim Kardashian is entering the chat with the relaunch of UPDATE, a beverage that gives you a jolt using paraxanthine, a lesser-known alternative to caffeine. (Kim has been a fan of the product since 2023, turning into a full-fledged partnership this year, according to reporting from Forbes.)

At a high level, paraxanthine is the compound your body naturally produces when it metabolises caffeine—and Kim and Ko. seem pretty sold on the ingredient. Available at Walmart starting March 1, the lightly carbonated cans promise to “eliminate the crash, jitters, and overstimulation” associated with traditional caffeine-based energy drinks, while still providing up to “four hours of focused energy when you need it most.”

Meet the experts: Jordan Langhough, RD, a registered dietitian; Tiffany Ma, RDN, a NYC-based sports performance dietitian; and Leslie Bonci, RD, MPH, a sports dietician based in Pittsburgh.

But does paraxanthine really live up to the hype? And, is it actually better than caffeine? Here’s what experts think.

What is paraxanthine?

Paraxanthine is the primary compound your body creates after you drink caffeine. In scientific parlance, it’s a metabolite—it’s what comes after your body breaks down and metabolises caffeine, just like how you get amino acids from protein. “When you have coffee or another caffeinated drink, your liver breaks that caffeine down into three smaller compounds: paraxanthine, theobromine, and theophylline,” says Jordan Langhough, RD, a registered dietitian. “Of those three, paraxanthine does most of the heavy lifting, since it makes up about 70 to 80 percent of what caffeine is metabolized into in most people,” she explains. (Meanwhile, theobromine is the star of the show when it comes to the caffeine metabolism of chocolate.)

Paraxanthine, like theobromine, theophylline—and caffeine itself—is a stimulant, says Leslie Bonci, RD, MPH, a sports dietician based in Pittsburgh. Put simply, paraxanthine is what drives that bright, switched-on feeling you get after your first cup of coffee. It works by blocking adenosine receptors in the brain (the chemical that makes you feel tired). By blocking it, paraxanthine helps dial down fatigue and boost alertness, explains Tiffany Ma, RDN, an NYC-based sports performance dietitian.

Is paraxanthine better than caffeine?

There’s not much evidence that paraxanthine is better than caffeine. In fact, there isn’t much of a difference between the two at all, since one is just the broken-down version of the other. “It’s like a rose by any other name,” Bonci says. “It’s all part of that same molecule. It’s just semantics. It’s not any better. It’s not any worse. They’re both going to provide the stimulant effect.”

Rather than being “better” than caffeine, paraxanthine is simply slightly different. “From a dietitian’s perspective, paraxanthine is best viewed as a promising alternative to caffeine rather than a proven upgrade,” Ma says, but more data is needed.

It’s also important to understand there’s no direct conversion between paraxanthine and caffeine, so approach with some caution. For example, if you know you tolerate a cup of coffee with 95 mg of caffeine or a can of Celsius with 200 mg, the same dosage of paraxanthine may have different effects.

“A drink may contain a specific number of milligrams of paraxanthine, but that doesn’t translate into an equivalent caffeine dose because they’re different compounds,” Ma says. Based on current research and product formulations, doses of 100 to 300 mgs of paraxanthine appear to produce noticeable effects in most people. (UPDATE sits at the high end of the range at 300 mg.) As with most energy drinks, it’s probably best to undershoot the dosage at first until you see how your body reacts to it.

Potential health benefits of paraxanthine

Early buzz and emerging research around paraxanthine are promising, but it’s important to keep things in perspective. Compared to caffeine, paraxanthine as a standalone supplement doesn’t have the same depth of long-term research behind it, Ma says. To date, most of the data comes from animal studies, and we don’t have enough large-scale human studies to confidently confirm all the purported benefits.

That said, some of the *potential* benefits of paraxanthine that experts are interested in learning more about are:

Improved cognition. Paraxanthine may enhance attention, improve reaction time, and boost cognitive performance, according to Langhough. Doses of 200 and 300 mg of paraxanthine were found to increase energy and productivity compared with a placebo in a 2025 study of 24 young adults, published in the Journal of the International Society of Sports Nutrition.Enhanced performance for athletes. As caffeine’s primary metabolite, paraxanthine may contribute to improved exercise output and stamina, Langhough says. A small 2024 study in the Journal of the International Sports Society of Nutrition found that consuming 200 mg of paraxanthine before a 10K run improved prefrontal cortex function, reduced attentional decline, mitigated cognitive fatigue, and boosted reaction time, suggesting it could be a caffeine-alternative nootropic for athletes.Improved fat utilisation for energy. A 2024 study done on caffeine in the European Journal of Medicinal Chemistry Reports suggests that paraxanthine may stimulate lipolysis—the metabolic process of breaking down fat to release fatty acids—which could help the body use fat as fuel during physical activity, according to Langhough.

With that in mind, paraxanthine is still a stimulant, so it may bring on some of the same side effects as caffeine, like increased heart rate, anxiety, restlessness, and sleep disruption, especially if you take higher doses, Ma says. Given such, pregnant people, anyone with heart issues, and those sensitive to stimulants should consult with a doctor before use.

The other ingredients in UPDATE, explained

In addition to paraxanthine, UPDATE includes several other supporting ingredients.

L-theanine: An amino acid naturally found in matcha and green tea, L-theanine is often paired with stimulants because it may promote a calmer, more balanced sense of alertness, Ma says. For example, some have tried adding the supp to their coffee in hopes of reducing stress and jitters, but there’s not much to support the hack. Related Stories