7 Best Non-Stim Pre-Workouts of 2024, Get More Energy without the Caffeine

Many of the best pre-workout supplements pack high doses of caffeine, which may not jive with the diets and training schedules of many athletes. Thankfully, many brands have begun to release caffeine-free alternatives. Rather than focusing on the energy boost, the best non-stim pre-workouts instead hone in on other aspects of the supplement, including workout endurance, blood flow, and more. 

“Pre-workouts can be an effective way to get the most benefit out of your workout sessions,” says Dr. Jennie Stanford, MD, FAAFP, DipABOM. “Many people associate pre-workouts with caffeine, but many non-stimulant pre-workout formulations are not only as effective as stimulants, but they also may provide other benefits, too.”

Of course, removing a key ingredient places added emphasis on other components to reap similar results. BarBend’s expert testers got their hands on dozens of different non-stim pre-workouts to see which ones could deliver a pump without making our hearts flutter. Grab a steaming cup of decaf, relax, and dive into our picks for the best non-stim pre-workouts available today.

The Best Non-Stim Pre-Workouts of 2024

• Best Non-Stim Pre-Workout Overall: Transparent Labs Stim-Free
• Best Budget Non-Stim Workout: Nutricost Pre-SF
• Best Non-Stim Pre-Workout for Pump: Legion Pulse (Caffeine-Free)
• Best Non-Stim Pre-Workout with Creatine: Gainful Non-Caffeinated Pre-Workout
• Best Non-Stim Pre-Workout for Muscle Gain: Gorilla Mind Nitric
• Best Non-Stim Pre-Workout for Cardio: 1st Phorm Endura-Formance
• Best All-Natural Non-Stim Pre-Workout: Genius Pre

Medical Disclaimer: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for the diagnosis, prevention, and/or treatment of health problems. It’s always a good idea to talk to your doctor before beginning a new fitness, nutritional, and/or supplement routine. 

Best Non-Stim Pre-Workouts Video Review

Join BarBend expert tester Jake Herod, NASM-CNC, and registered dietician nutritionist Chelsea Rae Bourgeois, MS, RDN, LD, as they discuss some of the best non-stim pre-workouts on the market in 2024, with a focus on pre-workouts from brands like Legion, Transparent Labs, and Onnit.

https://www.youtube.com/watch?v=XW7ubnaMY5o

Best Non-Stim Pre-Workout Overall: Transparent Labs Stim-Free

Pros

Includes added ingredients, like BCAAs

No caffeine

Seven flavor options

Cons

May cause a tingling feeling

Some may not love stevia

Just because you’re exercising in the evening (or just don’t love caffeine), doesn’t mean you have to forego pre-workout completely. Enter, Transparent Labs Stim-Free Pre-Workout.

“If you are exercising in the evening, it is important to look for a non-stimulant pre-workout if you plan to take one because caffeine consumed later in the day can negatively impact your sleep,” says Dr. Jennie Stanford, MD, FAAFP, DipABOM. “Sleep is crucial not only for recovery but also overall metabolic and cognitive health.”

“I love that Transparent Labs’ Stim-Free pre-workout is free of artificial sweeteners, colors, and preservatives,” said Chelsea Rae Bourgeois, M.S., RDN, LD, while assessing the product for BarBend. Rating the formulation a 4.5 out of 5, she touted its BCAAs as a key component of her high score. The hearty dose of 4,000 milligrams of 2:1:1 BCAAs can also help boost endurance, improve recovery, and muscle building, too. (3)

She did, however, have a small issue with the pre-workout’s use of SenActiv, a patented blend of two adaptogenic compounds. The compounds themselves aren’t a concern but proprietary blends makes it hard to know how much you’re exactly consuming.

In terms of taste, we rated the mixture a 3 out of 5. “I opted for the Cherry Limeade,” said our tester. “It was definitely tart, but not overly sweet like I’ve experienced with other Transparent Labs flavors.” 

To unlock this perk, though, be sure to give this stim-free pre-workout a good mixing, as clumps and “floaties” were noticeable within our shaker bottles when it came time to hit the gym. As such, we gave it a 2.75 out of 5 on our solubility scale, but our tester noted the “high-quality ingredients and ‘extras’ in the formula” weren’t diminished by a few loose chunks. 

“The tingles are fierce,” said our tester. “I get itchy fingertips and lips for roughly 10 to 15 minutes after a dose. It was a bit bracing at first.” For some, the four grams of beta-alanine may not be ideal.

Read our full Transparent Labs Stim-Free Review.

Best Budget Non-Stim Pre-Workout: Nutricost Pre-SF

Pros

Budget-friendly

Third-party tested

Available on Amazon Prime

Cons

Sweetened with sucralose

From a cost perspective, Nutricost Pre-SF is among the most budget-friendly, thanks to the sub-$1 price per serving. Other non-stim pre-workouts typically cost between $1.50 and $2.50 per dose, so having a tub that doesn’t cost you heavily for each training session is a definite plus. Our team gave this product a solid 5 out of 5 for cost.

Within this non-GMO, vegan-friendly formulation, you’ll find six grams of L-citrulline, which studies show can help improve nitric oxide production, leading to better blood flow and a more filling aesthetic in between sets. (7) We also like that this value is in line with the clinically-researched dose. (2)

[Related: Non-Stim Vs. Stim Pre-Workout]

Nutricost Pre-SF comes in three different flavors, including Blue Raspberry, Peach Mango, and Pink Lemonade. However many customers noticed that the product did leave some floating bits even after mixing in a shaker cup, so we had to give the solubility a 3.5 out of 5 rating.

Generally, we like the ingredient dosage of this formula, however, we did notice that Nutricost uses sucralose to sweeten their product. In some cases, artificial sweeteners can cause digestive unrest.

Best Non-Stim Pre-Workout for Pump: Legion Pulse (Caffeine-Free)

Pros

8g of citrulline malate may help with pump

All-natural ingredients

Contains alpha-GPC instead of caffeine

Cons

No unflavored option

Only 20 servings per container

After testing dozens of their products over the years, we’ve become big fans of Legion, a supplement company that foregrounds transparency with clear labeling, third-party testing, and a total lack of proprietary blends. The non-stim version of Legion’s Pulse pre-workout wins for boosting blood flow and supplying a pump, thanks to the 8,000 milligrams of l-citrulline. (7) We’ve also earmarked regular variety of Pulse as one of the strongest pre-workouts available.

“I love that Legion Pulse is available with or without caffeine, and there’s no added sugar, food dyes, or other chemicals,” said Chelsea Rae Bourgeois, M.S., RDN, LD, while assessing the product for BarBend. “Plus, It’s third-party tested for safety, giving you that extra peace of mind.” She rated the formulation a 4.5 out of 5. 

Aside from caffeine and l-theanine, this version of Pulse contains the same ingredients as its counterpart, including a 300-milligram dose of alpha-glycerylphosphorylcholine (alpha-GPC). According to some studies, this ingredient can help compensate for a lack of caffeine by potentially increasing motivation and enhancing cognitive performance in individuals. (8)(9)

As is the case with all of Legion’s products, the ingredients list on this supplement is appealingly slim, with no artificial sweeteners, food dyes, or added sugars.

We were mixed on the taste of the caffeinated Pulse. “I think it’s got a nice sweetness, but there is a bitter quality and the sweetener can leave a bit of an odd aftertaste,” said our tester, who rated its taste a 4 out of 5. You’ll find plenty of variety, though, as there are currently eight flavors available. We do, however, wish there was an unflavored option.

We’re also disappointed that each tub contains just 20 servings, which is 10 less than you’ll find in non-stim pre-workouts like Transparent Labs Non-Stim or 1st Phorm Endura-formance. Considering it costs $2.25 per serving, which is between $0.25 and $0.75 cents more per serving than other top pre-workouts, we rated its value a 2 out of 5.

Read our full Legion Pulse Pre-Workout Review. 

Best Non-Stim Pre-Workout with Creatine: Gainful Non-Caffeinated Pre-Workout

Pros

3,000mg creatine monohydrate

Customizable formula

Contains BCAAs

Cons

Only 14 servings per container

Only two flavor options

Taking creatine and a non-stim pre-workout supplement already? Maybe you want to combine the two? You’ve come to the right place. We think Gainful Pre-Workout is the best pre-workout with creatine because its customizable formula comes in both caffeinated and non-caffeinated options. You can also choose if you want a Moderate Intensity, Moderate Intensity + Creatine, or High Intensity + Creatine pre-workout formula.

The moderate intensity option with creatine contains 3,000mg of creatine monohydrate — the most studied form of creatine on the market. The high intensity option offers even more, coming in at 5,000mg of creatine monohydrate per serving.

Our tester opted for the High Intensity + Creatine formula and raved about it for convenience. “I love that I can get both my pre-workout and creatine in one scoop in the morning.”

But she did have one note of caution when it comes to the added 5,000mg of creatine in the High Intensity option. “I have a sensitive stomach, and I found that the higher dose of creatine can sometimes cause a little stomach upset if I take it first thing in the morning on an empty stomach.” She gave the formula a 4 out of 5 rating for that reason. That said, 5,000 milligrams (5 grams) is within the clinically recommended dose for creatine, albeit at the high end. (6)

Beside the creatine, this non-caffeinated pre-workout is a pretty well-rounded blend, also boasting citrulline, BCAAs, and beta-alanine. Our tester loved the flavor here too, giving the Strawberry Lemonade a very generous 5 out of 5 rating.

“I actually really enjoyed the taste, which doesn’t happen often for me when it comes to pre-workouts. The lemonade flavor is stronger than the strawberry, but it’s not too tart and the sweetness isn’t overpowering,” she says. A pro tip from her though: “It tastes a lot better cold,” as opposed to room temp.

Scouring the market for a pre-workout that is both non-caffeinated and contains creatine is no easy feat. Gainful Non-Caffeinated Pre-Workout is customizable to be both (or neither!) — a rare find, if we do say so ourselves.

Best Non-Stim Pre-Workout for Muscle Gain: Gorilla Mode Nitric

Pros

Contains creatine for muscle gain

Many flavor options

40 servings per container

Cons

Contains proprietary blends

There are cheaper options

If your main focus for supplementation is building strength and improving recovery, you’ll want a pre-workout that’s stacked with ingredients that support both. This pre-workout is dosed with creatine, which can help improve muscle strength, size, and performance.

“I like that you have flexibility with your dose and that the ingredients are third-party tested,” according to Chelsea Rae Bourgeois, RDN, rating the formulation a 4 out of 5. “There’s no caffeine, but it will likely put a pep in your step as you tackle your workout.”

Bourgeois likes that Gorilla Mode Nitric provides ingredient information for both one- and two-scoop doses. “I also appreciate that many of the ingredients are included in evidence-based doses,” she says.

Our team also gave the flavor a 4 out of 5 rating because we liked the wide variety. However, you may experience a sickly sweet aftertaste. Gorilla Mode Nitric uses the artificial sweetener sucralose, which can leave an odd aftertaste and, in some cases, may cause a little digestive unrest.

Where cost is concerned, this one earned a 4 out of 5. One 40-serving container costs $59.99, which is about $1.49 per serving. This certainly isn’t the most expensive product on our list but it’s not the absolute most budget-friendly you can find either.

Best Non-Stim Pre-Workout for Cardio: 1st Phorm Endura-Formance

Pros

May help boost aerobic performance

Contains creatine

We liked the Berry Lemonade flavor

Cons

Slightly thick mixture

Has proprietary blends

Pre-workouts aren’t just for strength athletes. As its name suggests, Endura-Formance is formulated to help you push longer and harder, making it a one the best supplements for runners. If you’re training for a marathon, you may benefit from a scoop before hitting the pavement. 

As our tester notes, Endura-Formance has a couple compounds you won’t see in many other pre-workouts: PeakO2 and S7. PeakO2 is composed of six adaptogenic mushrooms, including cordyceps militaris, which research has shown may have positive effects on aerobic performance and training volume for endurance athletes. (10) S7, meanwhile, is a combination of seven nutraceuticals that can significantly increase nitric oxide production, per a 2021 study. (11)

“To be honest, I don’t know if it’s actually working or if it’s the placebo effect, but I’ve been training for a triathlon and I can definitely feel it helping,” said our tester, who rated its effects a 5 out of 5.

When assessing the supp for BarBend, Chelsea Rae Bourgeois, M.S., RDN, LD, said that while she appreciates these ingredients for their potential to “improve oxygen uptake and utilization,” they are proprietary blends, meaning it’s unclear how much of each ingredient is included in each blend.

Still, she rated the overall formulation a 4.25 out of 5, with a special shout-out for its “science-backed doses” of creatine monohydrate and beta-alanine.

Our tester enjoyed other benefits from the supp’s blend of creatine, beta-alanine, betaine anhydrous, and L-tyrosine. “I use it for cardio, but I’ve pretty much started taking it before all of my workouts,” they said. “It’s particularly great for endurance, though, since it has a solid 195 milligrams of sodium.”We gave it strong marks in terms of taste (4.5 out of 5) and solubility (4 out of 5), too. 

[Related: What Are the Side Effects of Pre-Workout?]

“The Berry Lemonade flavor was excellent,” they said. “I found it slightly tart and not overly sweet. Also, no strange aftertaste.” We dinged it some in terms of solubility, as we were often left with a few loose chunks.

Best All-Natural Non-Stim Pre-Workout: Genius Pre

Pros

Natural ingredients

May promote focus

Minimal jitters

Cons

Doesn’t provide lasting pump

Has proprietary blends

All the best natural pre-workouts feature some of the cleanes blends you can buy for fueling up before training. In addition to being a caffeine-free pre-workout, Genius Pre contains no artificial flavors or added sugars. Instead, its strength-enhancing formulation is rounded out with ingredients like alpha-GPC and Rhodiola rosea that may improve both your physical and cognitive performance. (12)(13)

Highlights within the formulation include 6,000mg of citrulline malate, a non-essential amino acid which has been suggested to enhance recovery and performance due to its potential to increase nitric oxide production and L-arginine bioavailability. (7) As for AlphaSize (alpha-GPC), it’s often described as a “mind-to-muscle” ingredient, with research showing that it can boost brain metabolism, improve mental focus, and lead to enhanced muscle performance. (12)

“Genius Pre is marketed as a powerhouse pre-workout, and I think the motto fits,” said Chelsea Rae Bourgeois, a registered dietitian, when assessing the product for BarBend. “I like that Genius prioritizes L-citrulline malate in this pre-workout. Each serving contains 6 grams, the upper end of what research has found to be beneficial in these types of supplements.” 

She rated the formulation a 4 out of 5, dinging it slightly for the lack of clarity of what’s included in its proprietary blends. “While a lot of the proprietary blends used in Genius Pre are becoming more common in the market, I still prefer to know exactly what is in the supplements I’m taking,” she said.

Our tester certainly felt its benefits. “I would honestly describe the effects as euphoric, like I took a mood enhancer,” they said. “Since there’s no caffeine, I felt relaxed instead of stimulated.” They also experienced minimal jitters, noting the 2,000 milligram dose of beta-alanine, which is 1,000 to 2,000 milligrams less than you’ll find in other non-stim pre-workouts.

[Related: Coffee vs. Pre-Workout]

After taking the pre-workout, our tester worked their upper back and noticed a considerable pump in the shoulders, though it only lasted until shortly after the workout. They rated its effectiveness a 4 out of 5, adding that they’d not only take it again before a workout, but also to just “boost my focus throughout the day.”

We also loved the flavors and consistency, rating both its taste and solubility a 5 out of 5. “I tried the Blue Raspberry and loved how it sort of tasted like a blue ICEE,” they said, calling it one of the “best-tasting pre-workouts I’ve ever had — and I’ve tried well over 50 pre-workouts.” 

How We Tested and Chose the Best Stim-Free Pre-Workouts

The BarBend team is made up of competitive athletes, certified personal trainers, and lifelong fitness enthusiasts. To determine the best non-stim pre-workouts available today, we’ve tested 68 different products using BarBend‘s supplement testing methodology to rate each on a scale of 1 (lowest) to 5 (highest). Below are some of the categories and components that played into our rankings.

• Ingredient Formulation: Non-stim pre-workouts require other ingredients to offset the lack of ingredients like caffeine, and those results can’t be achieved without researched-backed dosages. (2) When looking at the best-performing stim-free pre-workouts, we want to ensure that most vital ingredients are served in an effective manner.
• Solubility: A pre-workout powder is sort of useless if it can’t mix properly before hitting the weights, right? To test this, we employed multiple preparation methods to see which supplements dissolved easily.
• Price Per Serving: The best stim-free pre-workouts cost between $1.50 and $2.50 per serving. We’ve done our best to give you a solid blend of budget-friendly and splurge-worthy options.
• Taste & Flavor Options: As subjective as taste can be, we still think it’s a worthwhile component to call out with certain pre-workouts. We tried to pick products that offered as many flavors as possible.

Common Ingredients In Non-Stim Pre-Workouts

Before buying a new pre-workout, it’s important to understand common pre ingredients and their purposes. When you have that base knowledge, you can make an informed decision about which formula and ingredient list may be best suited for your workout needs.

Betaine

Betaine is made in the body and can also be found in food sources like beets, broccoli, and shellfish. Betaine may be good for increasing strength and power, as two studies found proper supplementation to increase both disciplines by almost 25 percent. (14)

Beta-Alanine

Beta-alanine has been suggested to delay muscular fatigue, and enhance physical performance, especially in high-intensity anaerobic workouts. (15) The effective dose for beta-alanine is between 3,200mg and 6,400mg per day, but we recommend opting for a lighter serving if you find tingles to be unpleasant. (16)

BCAAs

BCAAs are typically found in a 2:1:1 ratio and are most commonly utilized to help increase muscle growth. More BCAA benefits include enhanced exercise performance and reduced fatigue, plus they can help speed up repair muscle damage after post-workout. (17) 

Citrulline

Citrulline may help produce more nitric oxide in your system, improving blood flow. It has may also help enhance performance and recovery. (7) A clinically effective dose of citrulline is considered to be about 6,000mg per day. (2)

Creatine

Creatine is a very popular supplement and is commonly used as a driver for improved muscle growth. Creatine has been shown, in various studies, to help improve performance and muscle mass in consistent users. (18)

The suggested dose of creatine will vary based on your size, muscle mass, and type of creatine, but in general, common recommendations fall between 3,000mg and 5,000mg per day after a loading period. (6)

Benefits of Non-Stim Pre-Workouts

Outside of the obvious exclusion of a stimulating ingredient like caffeine, stim-free pre-workouts can be just as influential on your workout experience as their original counterparts. Below are just a handful of the top perks that can be reaped from supplementing with these powerful powders.

• Improved Blood Flow: Non-stim pre-workouts may help you achieve a pump through high doses of key ingredients like citrulline, arginine, betaine (beetroot), and other nitric oxide boosters. (19)(20)
• Longer Muscular Endurance: Beta-alanine, creatine, and betaine are commonly used to help potentially improve endurance and power. (21)(15)
• Better Focus: Common ingredients like tyrosine, taurine, alpha-GPC, and theanine may help improve focus. (22)(23) Other nootropics, like Huperzine A, can also be used and have been backed by promising studies supporting its effect on cognitive function. (24)

How Much Do the Best Non-Stim Pre-Workouts Cost?

Non-stim pre-workouts tend to cost roughly the same as the average pre-workout, which we’ve found to cost between $1 and $2 per serving. Though a few picks on our list are above that range, the same goes for their caffeinated counterparts. As you can see in the below chart, our picks range in cost between 90 cents and $2.25 per serving. 

Best Non-Stim Pre-Workout Overall	Transparent Labs Stim-Free	$1.66 per serving
Best Budget Non-Stim Pre-Workout	Nutricost Pre-SF	$0.89 per serving
Best Non-Stim Pre-Workout for Pump	Legion Pulse (Caffeine-Free)	$2.25 per serving
Best Non-Stim Pre-Workout with Creatine	Gainful Non-Caffeinated Pre-Workout	$1.86 per serving
Best Non-Stim Pre-Workout for Cardio	1st Phorm Endura-Formance	$1.50 per serving
Best Budget Non-Stim Pre-Workout	Naked Nutrition Naked Energy	$0.90 per serving
Best All-Natural Non-Stim Pre-Workout	Genius Pre	$1.90 per serving

What to Consider Before Buying a Non-Stim Pre-Workout

We’ve had our hands on a number of stim-free pre-workouts over the years, and in that time we’ve learned how to best connect our purchases to our intended performance. Below are a few factors to keep in mind when searching for that ideal supplement for your setup.

Personal Goals

Depending on your goals, you may want more specific ingredients in your non-stim pre-workout. For example, if you intend to focus on gaining muscle, it may be wise to opt for a non-stim option with a heavy presence of creatine or other muscle-building ingredients.

Genius Pre-Workout

If you’re trying to withstand long, extensive sessions, look for formulations that cater to such a training style. Think about your pre-workout as just a piece of your training puzzle — the right piece with all the matching details is going to give you the best picture in the end.

Ingredients

Like your goals and aspirations, it’s important to think about your tolerances to certain ingredients as well, especially when stim-free pre-workouts can vary in robustness. If you’re sensitive to beta-alanine, for example, or want to avoid excessive tingling altogether, try to find a formulation with less beta-alanine present.

We also recommend taking your experience with pre-workouts into consideration, as this can help dictate whether you’re ready for a more extensive ingredients list. Those embarking on a beginner workout plan athletes may want to ease into pre-workout supplementation at first to help get a better understanding of what’s at play within each sip.

Research-Backed Dosages

Just because a non-stimulant pre-workout lists a key ingredient in its makeup doesn’t mean it can deliver a standard effect. The performance of these components are all reliant on proper dosing within each serving, so be sure to check whether your chosen pre-workout can leave you with just the right amount of boost for a given workout. We’ve listed many of the suggested daily dosages for key pre-workout components throughout this guide, but here’s a quick reminder for added clarity on some of the major ingredients:

• Creatine: 3-5 grams
• Citrulline: 3-6 grams 
• Citrulline Malate: 6–8 grams 
• Beta-Alanine: 3-6 grams

Price

The price of a pre-workout will fluctuate, but it should never break the bank. It’s important to figure out what your budget is and find a pre-workout that fits your budget. We also recommend looking at the price per serving, as this can be a good point of comparison between otherwise identical products.

Best Non-Stim Pre-Workout FAQs

References

1. Kaczka P, Batra A, Kubicka K, et al. Effects of Pre-Workout Multi-Ingredient Supplement on Anaerobic Performance: Randomized Double-Blind Crossover Study. Int J Environ Res Public Health. 2020;17(21):8262. Published 2020 Nov 9. https://doi:10.3390/ijerph17218262 
2. Glenn, J. M., Gray, M., Wethington, L. N., Stone, M. S., Stewart, R. W., Jr, & Moyen, N. E. (2017). Acute citrulline malate supplementation improves upper- and lower-body submaximal weightlifting exercise performance in resistance-trained females. European journal of nutrition, 56(2), 775–784. https://doi.org/10.1007/s00394-015-1124-6  
3. Rahimi MH, Shab-Bidar S, Mollahosseini M, Djafarian K. Branched-chain amino acid supplementation and exercise-induced muscle damage in exercise recovery: A meta-analysis of randomized clinical trials [published correction appears in Nutrition. 2018 Mar;47:115. https://doi: 10.1016/j.nut.2017.10.012]. Nutrition. 2017;42:30-36. https://doi:10.1016/j.nut.2017.05.005 
4. Puente-Fernández, J., Seijo, M., Larumbe-Zabala, E., Jiménez, A., Liguori, G., Rossato, C. J. L., Mayo, X., & Naclerio, F. (2020). Effects of Multi-Ingredient Preworkout Supplementation across a Five-Day Resistance and Endurance Training Microcycle in Middle-Aged Adults. Nutrients, 12(12), 3778. https://doi.org/10.3390/nu12123778
5. Lee MC, Hsu YJ, Shen SY, Ho CS, Huang CC. A functional evaluation of anti-fatigue and exercise performance improvement following vitamin B complex supplementation in healthy humans, a randomized double-blind trial. Int J Med Sci. 2023;20(10):1272-1281. Published 2023 Aug 15. https://doi:10.7150/ijms.86738 
6. Naderi A, de Oliveira EP, Ziegenfuss TN, Willems MT. Timing, Optimal Dose and Intake Duration of Dietary Supplements with Evidence-Based Use in Sports Nutrition. J Exerc Nutrition Biochem. 2016;20(4):1-12. https://doi:10.20463/jenb.2016.003 1
7. Gonzalez AM, Trexler ET. Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. J Strength Cond Res. 2020;34(5):1480-1495. https://doi:10.1519/JSC.0000000000003426 
8. Kansakar U, Trimarco V, Mone P, Varzideh F, Lombardi A, Santulli G. Choline supplements: An update. Front Endocrinol (Lausanne). 2023;14:1148166. Published 2023 Mar 7. https://doi:10.3389/fendo.2023.1148166 
9. Tamura Y, Takata K, Matsubara K, Kataoka Y. Alpha-Glycerylphosphorylcholine Increases Motivation in Healthy Volunteers: A Single-Blind, Randomized, Placebo-Controlled Human Study. Nutrients. 2021;13(6):2091. Published 2021 Jun 18. https://doi:10.3390/nu13062091 
10. Hirsch KR, Mock MG, Roelofs EJ, Trexler ET, Smith-Ryan AE. Chronic supplementation of a mushroom blend on oxygen kinetics, peak power, and time to exhaustion. J Int Soc Sports Nutr. 2015;12(Suppl 1):P45. Published 2015 Sep 21. https://doi:10.1186/1550-2783-12-S1-P45 
11. Nemzer, Boris & Fink, Nelli & Fink, Bruno. (2014). New insights on effects of a dietary supplement on oxidative and nitrosative stress in humans. Food Science & Nutrition. 2. https://doi:10.1002/fsn3.178.  
12. Bellar D, LeBlanc NR, Campbell B. The effect of 6 days of alpha glycerylphosphorylcholine on isometric strength. J Int Soc Sports Nutr. 2015;12:42. Published 2015 Nov 17. https://doi:10.1186/s12970-015-0103-x 
13. Ivanova Stojcheva E, Quintela JC. The Effectiveness of Rhodiola rosea L. Preparations in Alleviating Various Aspects of Life-Stress Symptoms and Stress-Induced Conditions-Encouraging Clinical Evidence. Molecules. 2022;27(12):3902. Published 2022 Jun 17. https://doi:10.3390/molecules27123902 
14. Arazi, H., Aboutalebi, S., Taati, B., Cholewa, J. M., & Candow, D. G. (2022). Effects of short-term betaine supplementation on muscle endurance and indices of endocrine function following acute high-intensity resistance exercise in young athletes. Journal of the International Society of Sports Nutrition, 19(1), 1–16. https://doi.org/10.1080/15502783.2022.2041988  
15. Saunders B, Elliott-Sale K, Artioli GG, et al. β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Br J Sports Med. 2017;51(8):658-669. https://doi:10.1136/bjsports-2016-096396 
16. Trexler, E. T., Smith-Ryan, A. E., Stout, J. R., Hoffman, J. R., Wilborn, C. D., Sale, C., Kreider, R. B., Jäger, R., Earnest, C. P., Bannock, L., Campbell, B., Kalman, D., Ziegenfuss, T. N., & Antonio, J. (2015). International society of sports nutrition position stand: Beta-Alanine. Journal of the International Society of Sports Nutrition, 12, 30. https://doi.org/10.1186/s12970-015-0090-y 
17. Arroyo-Cerezo, A., Cerrillo, I., Ortega, Á., & Fernández-Pachón, M. S. (2021). Intake of branched chain amino acids favors post-exercise muscle recovery and may improve muscle function: optimal dosage regimens and consumption conditions. The Journal of sports medicine and physical fitness, 61(11), 1478–1489. https://doi.org/10.23736/S0022-4707.21.11843-2 
18. Wu SH, Chen KL, Hsu C, et al. Creatine Supplementation for Muscle Growth: A Scoping Review of Randomized Clinical Trials from 2012 to 2021. Nutrients. 2022;14(6):1255. Published 2022 Mar 16. https://doi:10.3390/nu14061255 
19. Figueroa A, Wong A, Jaime SJ, Gonzales JU. Influence of L-citrulline and watermelon supplementation on vascular function and exercise performance. Curr Opin Clin Nutr Metab Care. 2017;20(1):92-98. https://doi:10.1097/MCO.0000000000000340 
20. Wu G, Meininger CJ, McNeal CJ, Bazer FW, Rhoads JM. Role of L-Arginine in Nitric Oxide Synthesis and Health in Humans. Adv Exp Med Biol. 2021;1332:167-187. https://doi:10.1007/978-3-030-74180-8_10 
21. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. Published 2017 Jun 13. https://doi:10.1186/s12970-017-0173-z 
22. Steenbergen L, Sellaro R, Hommel B, Colzato LS. Tyrosine promotes cognitive flexibility: evidence from proactive vs. reactive control during task switching performance. Neuropsychologia. 2015;69:50-55. https://doi:10.1016/j.neuropsychologia.2015.01.022 
23. Jongkees BJ, Hommel B, Kühn S, Colzato LS. Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands–A review. J Psychiatr Res. 2015;70:50-57. https://doi:10.1016/j.jpsychires.2015.08.014 
24. Friedli MJ, Inestrosa NC. Huperzine A and Its Neuroprotective Molecular Signaling in Alzheimer’s Disease. Molecules. 2021;26(21):6531. Published 2021 Oct 29. https://doi:10.3390/molecules26216531 
25. Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy–A Review. Nutrients. 2016;8(2):68. Published 2016 Jan 27. https://doi:10.3390/nu8020068 
26. Cristina-Souza G, Santos-Mariano AC, Lima-Silva AE, et al. Panax ginseng Supplementation Increases Muscle Recruitment, Attenuates Perceived Effort, and Accelerates Muscle Force Recovery After an Eccentric-Based Exercise in Athletes. J Strength Cond Res. 2022;36(4):991-997. https://doi:10.1519/JSC.0000000000003555