What You Should Know About Stimulant-Free Pre-Workout Supplements

A SAVVY CONSUMER like you knows that supplements are a largely unregulated industry, with supplement companies advertising all kinds of supposed benefits for their pills, powders, and potions. Stimulant-free pre-workout supplements are a perfect example.

Pre-workout supplements deliver their powerful dose of energy through one main ingredient: caffeine. “Stimulant-free” pre-workout supplements don’t contain (you guessed it) caffeine.

But by removing removing caffeine, will your pre-workout even do anything? Plus, isn’t stimulation a big part of the reason you’re taking pre-workout in the first place?

It’s important to point out that you don’t need pre-workout to have a good gym session—real food sources like a banana, oatmeal, or—if you feel like you need the buzz—a cup of coffee can help you power through.

But if a supplement is more your thing, it’s fair to wonder if you should at least consider stimulant-free pre-workout supplements. Here’s what two performance dietitians want you to keep in mind before adding one to your cart.

So, what are stimulant-free pre-workout supplements?

They’re pre-workout supplements that don’t contain caffeine, says Albert Matheny, RD, CSCS, co-founder of SoHo Strength Lab.

Stimulant-free pre-workout supplements are still designed to boost workout performance by relying on ingredients like beta-alanine, creatine, citrulline malate, taurine, betaine, and various nitric oxide precursors, explains Scott Keatley, RD, of Keatley Medical Nutrition Therapy. “These are supposed to enhance blood flow, delay fatigue, or support muscular endurance through non-stimulant mechanisms,” he says.

“They may at least claim to give you energy,” Matheny says.

Many stimulant-free pre-workout supplements advertise that they’ll enhance your performance by increasing oxygen delivery, enhancing muscular “pump,” buffering lactic acid, or improving mental focus, all without the typical stimulant buzz, Keatley says.

“For example, beta-alanine may buffer acid buildup and reduce muscular fatigue, citrulline malate is intended to increase nitric oxide, which may improve blood flow, and creatine helps recycle ATP, fueling short bursts of high-intensity activity,” he says.

But do they actually work?

Dietitians say there’s a lot of marketing hype around these supplements.

“In isolation, several of these ingredients have research to back them, but not in the way most of these blends are used,” Keatley says. “Many products under-dose ingredients, combine them in undisclosed ratios, or stack compounds that compete or interact unpredictably.”

He recommends being on the lookout for the term, “proprietary blend,” which can be a red flag. “It hides the dosing, so you don’t know what you’re really getting,” he says.

So don’t confuse “stimulant-free” with “safe.” “Beta-alanine can cause paresthesia—that itchy skin sensation—high-dose niacin can cause flushing, and unregulated supplements can be contaminated with banned substances or stimulants despite being labeled ‘stim-free,’” Keatley says.

Should you consider a stimulant-free pre-workout supplement?

Dietitians say you’re unlikely to get the same benefits from a stimulant-free pre-workout as you would something with caffeine. (“The stimulant-free pre-workout probably won’t give you the same punch you’re thinking about,” Matheny says.)

Keatley recommends being wary of marketing. “If you’re chasing marginal gains and you’re aware of what you’re taking and why, isolated ingredients like creatine or citrulline can be part of a targeted approach,” he says. “But if you’re scooping a random stim-free powder because the label promised ‘explosive pumps’ or ‘endurance like never before,’ you’re likely just paying for fancy marketing.”

Keatley also stresses that you don’t need pre-workout in the form of a supplement. “If you’re eating well, hydrating properly, and sleeping enough, you don’t need a stim-free pre-workout,” he says. “And if you want the proven benefits of something like creatine or beta-alanine, just take those ingredients on their own, in the right dose, and skip the mystery cocktail.”