What to Look For in Pre-Workout Supplements (and What to Avoid)

Pre-workout powders are among the most popular supplements in the world of sports nutrition. These products are a staple for many gym-goers as they can improve strength and power, enhance endurance, increase focus, facilitate muscle protein synthesis, and enhance nitric oxide production (i.e. increase blood flow and muscle pumps). Sounds pretty great, right? Well, it certainly can be...if you know which pre-workout supplement ingredients are effective.

The pre-workout niche comprises thousands of products promising to take your workouts to new heights. Unfortunately, it can be hard to decipher which pre-workout ingredients work and which are pretty much bunk (or even harmful). 

Moreover, quality control is often lacking in the supplement industry, leaving consumers with the onus of distinguishing between honest and untrustworthy brands. As such, knowing what to avoid and what to look for in pre-workout supplements will save you a lot of time (and your hard-earned money). We'll cover the basics of pre-workout "green flags" and "red flags" in this guide.

What to Avoid in Pre-Workouts: Six Red Flags

In a deductive fashion, you can weed out low-quality pre-workouts by knowing what to avoid. Below are some of the more prominent "red flags" that signal you should steer clear of a pre-workout supplement:

• Proprietary Blends

  • A proprietary blend is a mixture of ingredients in undisclosed amounts. In other words, these blends may contain numerous ingredients with no specifics about their dosing individually. Hence, they are “proprietary” (read: trade secret). Many pre-workouts contain at least one, if not several, proprietary blend(s) under the guise of a clever name on the ingredient panel, such as “Mental Focus Blend.” The blend will have a total dose listed next to it, but the doses of each ingredient in the blend are anyone's guess.

    The fact of the matter is simple: if a supplement company isn't willing to tell you exactly what's in their products, whether it's a pre-workout powder or not, it's because they don't want you to know. As a consumer, you have the right to demand transparency, especially with something you're ingesting to (hopefully) better yourself and your performance.

• Under-Dosed Ingredients ("Label Dressing")

  • Consider a pre-workout supplement that contains 500 mg of "ingredient X" when the evidence-based dosage is 4-6 grams (4,000 - 6,000mg). Would you expect that ingredient to do much? Of course not.

    Sadly, this is how many pre-workout supplements are formulated, and it's even sadder that this is often a deliberate tactic called "label dressing."

    Why do supplement companies do this, you ask? Well, it allows them to fill the label with numerous ingredients to support claims about the product. These companies hope and pray you're not a savvy consumer who reads between the lines and notices that the doses are well below what is effective in research.

• Misrepresenting Science

  • Many supplement brands have become adept at "cherry-picking" their data and exaggerating research for specific ingredients. In other words, they wittingly (or perhaps unwittingly) only present the studies that favor the claims they want to make about the ingredients in their pre-workout products, while never mentioning the studies that show the contrary. This allows them to sway credulous consumers by not providing the whole picture.

• Artificial Food Dyes

  • Pre-workout powders come in a variety of colors depending on the additives that are used. If you see ingredients like "FD&C Blue Lake 2" or "Sunset Yellow" in a pre-workout, it has artificial food coloring. While artificial food dyes aren't outright "bad" or "toxic," but the safety of their ubiquity in foods, beverages, and supplements remains controversial. A growing body of evidence suggests synthetic/artificial food coloring may be harmful in doses relevant to everyday consumption [1].

    Researchers note that various synthetic food dyes increase inflammatory response and inhibit enzymes responsible for metabolizing noxious compounds [2]. The simple workaround is to look for a pre-workout supplement that uses natural food coloring, like beetroot powder, pineapple powder, or spirulina, instead of synthetic dyes.

• Fillers and Unnecessary Additives

  • Another cheap tactic that seems especially prevalent in the pre-workout supplement space is the use of "filler" ingredients, like maltodextrin, rice flour, and dextrose, to increase serving size. Adding a few grams of these ingredients, which are essentially just sources of sugar, gives the unknowing consumer the sense that the product is more potent despite the active ingredients likely being under-dosed.

• Unclear Ingredient Nomenclature

  • Using an ingredient's chemical compound name, like 1,3,7-trimethylxanthine instead of simply "caffeine," misleads consumers despite being technically accurate. Supplement companies may do this to conceal the true nature of an ingredient. This tactic can be used the other way around, too; for example, pre-workout products that list "geranium extract" as an ingredient actually contain the banned stimulant 1,3-DMAA (dimethylamylamine). The use of such jargon is simply not what you should expect in a quality pre-workout formula.

Green Flags: Pre-Workout Ingredients Backed by Science & Dosed Properly

Now that we've covered what not to look for in pre-workout formulas, let's transition to the good stuff—the "green flags," if you will. Here are five evidence-based ergogenic ingredients that, when dosed properly, can propel athletic performance as part of a pre-workout formula:

Caffeine

Caffeine is a naturally occurring methylxanthine that predominately stimulates the central nervous system by blocking adenosine receptors and inhibiting phosphodiesterase activity [3]. In so doing, caffeine enhances focus, energy levels, and fat oxidation ("burning") during exercise while also reducing the rate of perceived exertion and muscle fatigue [4].

More simply, the caffeine in a pre-workout supplement allows you to train harder, longer, and more effectively. Hence, caffeine anhydrous is one of the most common ingredients in pre-workouts.

A range of studies show that a moderate pre-workout dose of caffeine (e.g. 200 mg of caffeine per serving) significantly improves both physical and mental performance aspects of aerobic and anaerobic exercise [5]. ("Moderate dose" meaning 2-4 mg of caffeine per kg of body weight.)

However, beginners sensitive to stimulants may fare better with caffeine-free pre-workouts.

L-Citrulline

L-Citrulline is a non-proteinogenic amino acid first discovered in the rind of watermelon (Citrullus lanatus). Hence, "citrulline" is an eponym of the scientific name for "watermelon."

Instead of being used for protein synthesis like branched-chain amino acids (BCAAs), L-citrulline has a well-established role in the urea and nitric oxide (NO) cycles. It is a precursor and metabolite of L-arginine, a conditionally essential amino acid [6].

As part of the nitric oxide cycle, arginine is converted to citrulline, thereby releasing NO and promoting better blood flow. Interestingly, L-citrulline is more effective than L-arginine in increasing NO production [7].

Citrulline acts like a reservoir of arginine and, therefore, NO in the body. As such, citrulline is arguably the best pre-workout ingredient to amplify the esteemed "muscle pump" that bodybuilders and gym-goers crave.

Numerous studies have also shown that taking 4 – 8 grams of L-citrulline before exercise can significantly increase oxygen uptake (VO2 max) and reduce blood lactate levels, which are conducive to athletic performance, recovery, and muscle cell volumization [8, 9, 10]. A good pre-workout for beginners should contain at least 4 grams of L-citrulline for proper efficacy.

Note: In contrast to citrulline malate — the citrulline salt of malic acid — pure L-citrulline is the native free-form amino acid (the most researched form of L-citrulline). However, citrulline and citrulline malate are both effective pre-workout ingredients for exercise performance and blood flow since malic acid appears to have ergogenic properties of its own [11].

Beta-Alanine

Beta-alanine—not to be confused with betaine anhydrous—is another non-proteinogenic amino acid and the rate-limiting factor for muscle carnosine synthesis. When beta-alanine bonds to histidine, the dipeptide carnosine forms. Carnosine is an essential buffer in muscle cells that helps maintain optimal cellular pH during strenuous exercise.

A strongly acidic (i.e. low pH) cellular milieu reduces muscle contractile force, causing fatigue during exercise. Carnosine buffers muscle pH by neutralizing free hydrogen ions (H+) and attenuating lactic acid buildup, ultimately increasing your capacity to train harder and longer [12]. As such, beta-alanine is arguably one of the best pre-workout ingredients for athletes and gym-goers looking to boost anaerobic and aerobic workout performance.

The recommended dose of beta-alanine ranges from 2,400 to 4,500 mg, with research showing muscle carnosine increases as much as 58% after just four weeks of supplementing with 2,500 mg of beta-alanine daily [13]. It's best to start on the lower end of the range as beta-alanine may cause a tingling sensation in the skin, especially for first-time users.

Creatine Monohydrate

The body naturally produces creatine in small amounts to help sustain cellular energy (ATP) for vital biological processes. During high-intensity workouts, however, muscles constantly use ATP to perform work (i.e. contract).

Creatine monohydrate bolsters the ATP regeneration process, and it is unequivocally effective for increasing strength and building muscle [14]. Creatine monohydrate also has an exceptional safety profile in healthy adults [15].

Moreover, creatine monohydrate has been consistently shown to improve athletic performance, especially during high-intensity training like weight lifting and running sprints.

Over time, taking creatine can boost muscle strength, increase muscle growth, and help reduce recovery time between workouts [16].

While not a pre-workout per se, creatine monohydrate works great as either a pre-workout or post-workout supplement. You can easily add it to your favorite pre-workout supplements if it's not already in them. The key is taking creatine monohydrate consistently — 3,000 mg to 5,000 mg daily — to saturate muscle creatine stores.

Be wary that supplement companies often cut corners and use bulk-sourced creatine monohydrate rife with impurities (e.g. heavy metals and organic synthesis contaminants) [17]. As such, Transparent Labs Creatine HMB packs 5,000 mg of creatine monohydrate that's tested for quality and purity, plus 1,500 mg of synergistic hydroxymethyl butyrate (HMB) and vitamin D for enhanced muscle growth.

Betaine (Anhydrous)

Betaine, also known as trimethylglycine, is a worthy pre-workout ingredient due to its versatile biochemical mechanisms and osmolytic nature—enhancing cellular hydration and, potentially, blood flow. At the molecular level, betaine is an important methyl donor, particularly in converting homocysteine to methionine. This conversion is an integral step in reducing blood homocysteine levels—a risk factor in cardiovascular health—and for regenerating methionine, which in turn supports creatine synthesis [18].

Research on betaine supplementation shows that it can produce moderate increases in muscle strength and muscle endurance during compound exercises like squats and bench presses [19, 20]. The clinically effective dose of betaine ranges between 1.25 and 2.5 grams per day.

Quality Matters When Choosing a Pre-Workout Supplement

Now that you know the ingredients to look for in pre-workouts, the final step is ensuring you purchase a quality pre-workout formula. The reality is you get what you pay for, and many supplement companies are just in it to move as much product as possible at the expense of quality, efficacy, and safety. In most cases, you're better off spending a little extra on dietary supplements with a proven track record.

This is why Transparent Labs BULK Pre-Workout is so dependable and highly rated — the formula is entirely transparent, with exact amounts of all active and inactive ingredients on the label. Each active ingredient is chosen based on science and clinical research instead of anecdotes and conjectures, and every batch is third-party tested for purity, potency, and authenticity. These are the quality standards you should demand from pre-workout supplements, even if you decide to buy from a different brand.