One fitness supplement can help you build muscle and maybe boost longevity without breaking the bank, according to experts

• Creatine may be the best-value fitness supplement you can buy for performance and health.
• Top trainers and scientists consistently recommend it to build muscle, burn fat, and even protect your brain.
• While creatine is relatively cheap and safe to use, no supplement can replace a healthy lifestyle.

Stop wasting your time and money on subpar supplements.

One ingredient should be your first priority for building muscle, burning fat, and aging gracefully, according to exercise science pros.

Creatine is a combo of amino acids that provides energy to muscles and other tissues, like the brain. Our bodies produce it naturally, but growing research suggests supplementing with store-bought pills and powders is a smart idea.

It's long been the uncontested king in the fitness supplement world for fueling gains, personal trainers, dietitians, and researchers told Business Insider. Now, even more studies suggest it has benefits beyond the gym, helping bolster the brain to support mental and cognitive health.

For less than 50 cents a serving, it's the gold standard of evidence-based health hacks, with an impressive resume of potential perks.

Want to start taking creatine? Here's how it works, and the best way to use it for peak performance, according to top researchers.

Creatine helps fuel more reps, leading to better gains

Long a staple of the sports world and bodybuilding community alike, creatine has been extensively studied as a fitness supplement for decades. It first caught on in the '90s thanks to Olympians who swore by it for elite athletic competition.

Since then, researchers have consistently found that it's safe to use and offers a small but significant boost to performance.

It works by providing extra fuel in the body's energy cycle. That translates to better gains or faster fat burning if you're working out, since you can power through more work that you might otherwise.

That makes it a standout performer in the supplement aisle. Creatine has much stronger evidence and broader benefits than products like pre-workouts, which can vary in ingredients and often don't disclose what's actually included.

It's also distinct from protein shakes and powders, which offer the same nutritional benefits as food, but in a more convenient format. There is some creatine in foods like meat and fish, but it's much harder to get than protein — you'd have to eat more than two pounds of steak to get the amount of creatine in a single scoop of supplement powder.

Other supplements are less evidence-based, less reliable, and can have more risks, particularly when bought online via grey-market websites.

The only supplement that comes close to challenging creatine in terms of wide-ranging benefit and extensive research is caffeine. While caffeine can boost workouts and is relatively safe in moderate doses, it can have serious side effects in large amounts, so you're better off having a coffee than a concentrated supplement.

The best type of creatine to choose for muscle gains and fat loss

Not all creatine on the market is the same. The most well-researched form is creatine monohydrate, which sports nutritionists consider reliably effective and safe. If you're worried it causes hair loss or kidney damage, don't be: these are myths that have been debunked in reputable studies.

Creatine can have side effects like digestive upset, which is typically mild, temporary, and linked to higher doses.

It's also safe for your wallet. Even with past shortages, creatine monohydrate tends to be the cheapest form, especially if you buy it pure instead of mixed into complicated pre- or post-workout blends.

To take creatine, researchers typically recommend a dose of between 3 to 5 grams a day (people with larger bodies need more). However, emerging studies suggest the brain can benefit from higher doses. Scott Forbes, a sports science researcher and professor at Brandon University, said he recommends around 10 grams a day for cognitive health.

Still, despite all the potential benefits of creatine, it's not a panacea. No supplement, no matter how well-researched, can match the benefits of healthy lifestyle factors such as nutrition, sleep, and consistent exercise. Trainers recommend starting with high-value habits such as these first before trying supplements.

Once you're nailing your workouts, diet, and recovery, creatine may be just the thing to give your routine an extra edge.