Best Pre-Workout Ingredients & Supplements 2025

If you want to take your exercise performance to the next level, choosing the best pre-workout ingredients for your specific goals is essential. But as soon as you start exploring pre-workout supplements, it becomes clear, there are a lot of options out there.

Who this guide is for: athletes, lifters, and committed gym-goers who want clear, evidence based recommendations (not hype). You’ll learn which ingredients are actually backed by research, how to dose them, and which formulas fit your goals.

Quick jump to what you need:

1. Top Ingredients (with doses)
   
2. Ingredient Summary Table
   
3. Best Pre-Workouts by Goal 
   
4. FAQs

The 10 Best Pre Workout Ingredients

There are hundreds of dietary supplement ingredients that promise to boost workout performance and recovery, but only a few have evidence-backed benefits.

Don't worry, we compiled a list of the 10 best pre-workout ingredients and their effective dosages.

Most of these ingredients can be found in the Transparent Labs PreSeries lineup, but not all since some have overlapping benefits with unlikely synergy (making them redundant).

1. Citrulline Malate

L-citrulline is an amino acid found in watermelon, and is a popular ingredient in pre-workout supplements due to its ability to boost nitric oxide levels [1]. When nitric oxide production increases, blood flow improves and allows both nutrients and oxygen to replenish muscle tissue more efficiently. Ultimately, this translates to greater muscle pumps and heightened energy levels.

While L-citrulline is ideal for bodybuilders and those who lift weights, endurance athletes may also benefit from it [2]. In fact, L-citrulline malate, the citrulline salt of malic acid, is one of the most common pre-workout ingredients.

However, pure L-citrulline is seemingly just as effective as citrulline malate, so long as the doses of citrulline are matched. Malic acid is an important intermediate compound involved in energy production, but its ergogenic effects remain to be demonstrated.

Additionally, research has found that citrulline malate enhances the anti-catabolic effects of branched-chain amino acid (BCAA) supplements [3].

It isn't uncommon for citrulline to be replaced with L-arginine, beetroot, or agmatine sulfate to support nitric oxide production. When dosed appropriately, these ingredients will increase circulation and blood flow to skeletal muscle. However, citrulline and citrulline malate tend to be the most effective of the bunch.

Studies indicate that the optimal dose of citrulline (malate) is 4 – 8 grams taken before a workout [4]. However, most pre-workouts on the market only contain around 1 – 2 grams of citrulline due to its cost.

2. Beta-Alanine

Beta-alanine is a beta-amino acid that combines with L-histidine to form a dipeptide known as carnosine. Since beta-alanine is the rate-limiting substrate for carnosine synthesis, supplementing with this amino acid can rapidly increase muscle carnosine levels. In turn, carnosine acts as a buffer that neutralizes acidic byproducts of intense exercise [5].

Numerous studies are now available demonstrating the efficacy of beta-alanine as a pre-workout supplement. Relevant benefits of beta-alanine include improving muscular endurance, reducing muscle fatigue, and supporting muscle growth [6].

However, many pre-workout supplements miss the mark on beta-alanine by skimping on the dose. Research suggests that active individuals need 3 – 5 grams of beta-alanine daily for ergogenic benefits [7].

Beta-alanine is an oft-maligned sports supplement due to a harmless side effect known as paresthesia (which resembles a tingling sensation under the skin). Thankfully, this side effect dissipates if you use beta-alanine consistently.

This pre-workout ingredient doesn't necessarily need to be taken right before exercise. Much like creatine, your carnosine concentrations will remain effectively elevated if you take beta-alanine daily.

3. Betaine Anhydrous (Trimethylglycine)

Betaine anhydrous, aka trimethylglycine, is an amino acid derivative found primarily in beetroot. The body also produces betaine endogenously, as it's an essential regulator of homocysteine levels and cellular fluids.

More specifically, betaine is an important methyl donor that impacts several physiological processes from DNA replication, blood pressure balance, and neurotransmitter function [8].

Studies suggest that supplemental betaine may provide several benefits, including:

1. Improving body composition [9]

2. Increasing power output and force [10, 11]

3. Boosting muscular endurance [12]

Effective doses of betaine anhydrous fall between 2,400 and 4,000 mg taken prior to exercise.

4. Branched-Chain Amino Acids (BCAA)

Branched-chain amino acids (BCAA) are one of the most common ingredients found in pre-workout formulas, particularly stim-free pre-workouts. The term "BCAAs" refers to three essential amino acids: leucine, isoleucine, and valine. 

Leucine is widely considered the most important of the three BCAAs, working to activate the mTOR pathway responsible for muscle protein synthesis. And while isoleucine is suggested to increase glucose uptake by skeletal muscle cells, the effects of valine supplementation are less patent [13]. However, it's thought that valine inhibits tryptophan metabolism, which may augment athletic performance.

BCAAs, as a whole, have been shown to reduce muscle soreness and prevent muscle wasting, particularly during weight-loss phases [14]. BCAA supplementation may also improve stamina by sparing muscle glycogen during exercise. One study even demonstrated significant power increases in subjects given pure L-leucine [15].

5. L-Theanine + Caffeine

We all know the energizing effects of caffeine supplementation — the "pep" kicks in minutes after drinking a cup of coffee or slamming an energy drink. Yet, many aren't aware that L-theanine — an amino acid in green tea — bolsters the cognitive benefits of caffeine [16].

Therefore, pairing L-theanine with caffeine in the evidence-based 3:2 or 2:1 ratio is prudent before hitting the gym. L-theanine and caffeine work together to improve reaction time, focus, cognition, and mental acuity [17].

Although caffeine is unique in the way it immediately ramps up your alertness and motivation, be mindful of the slippery slope of tolerance. Many people fall victim to ever-increasing caffeine dosages in pre-workouts.

We suggest keeping your daily caffeine intake below 7 mg per kg of body weight. Too much caffeine can cause heart palpitations, tremors, restlessness, and anxiety.

Fortunately, taking L-theanine with caffeine (anhydrous) can help attenuate the side effects of the former. Hence, PreSeries LEAN and PreSeries BULK both have generous amounts of L-theanine to go along with caffeine.

6. CDP-Choline or Alpha-GPC

Choline is an essential B vitamin that the body needs to create the neurotransmitter acetylcholine, which plays a major role in cognitive function. Unfortunately, choline is commonly lacking in the modern diet; In fact, 94% of the adults in one study had a choline deficiency [19]. As such, taking a choline supplement is generally wise even if you're not an avid gym-goer.

There are three popular forms of supplemental choline: choline bitartrate, CDP-choline, and alpha-GPC. While choline bitartrate may sound familiar — especially if you're into nootropics — you may not be up to speed on alpha-GPC and CDP-choline (citicoline).

In contrast to choline bitartrate, alpha-GPC and CDP-choline are highly bioavailable sources of choline that enhance mental acuity and physical performance [18]. Choline bitartrate can still be an effective pre-workout ingredient, but the dose needs to be quite a bit higher (e.g. two to three times more) than alpha-GPC and CDP-choline. An effective dose of the latter two options ranges between 150-600 mg.

7. elevATP®

elevATP® is a patented extract of ancient peat that's suggested to fortify cellular ATP levels. Thus, elevATP® can boost exercise performance and has been demonstrably effective in a handful of human studies [20, 21, 22].

The recommended dose of elevATP® ranges from 150 mg to 300 mg per day, taken before and/or after training.

8. Taurine

Taurine is another worthwhile pre-workout ingredient with multifarious benefits for athletes and gym-goers. For one, taurine is a potent brain booster that confers synergy with caffeine to boost focus and reduce brain cell inflammation and oxidative stress [23]. 

Taurine can also boost performance via increased blood flow to skeletal muscle tissue [24, 25]. Greater blood flow to muscle tissue can enhance muscle growth and recovery after a tough workout. Taurine supplementation has even been shown to improve performance in endurance athletes [26].

An effective dose of taurine is 1 – 2 grams taken shortly before exercise. Taurine is also generally recognized as safe, as it's created naturally in the body and present in many foods, particularly seafood, poultry, and beef.

9. Acetyl L-Carnitine

Acetyl L-carnitine (ALCAR) is the more bioavailable and cognitively active form of L-carnitine, an important molecule that transports long-chain fatty acids into mitochondria so they can be used as energy [27].

ALCAR has been shown to reduce the symptoms of muscle damage and oxidative stress after resistance training in healthy, adult males [27]. Further evidence suggests that ALCAR has neuroprotective benefits and can improve blood flow to the brain [28].

A recent meta-analysis also highlights the efficacy of ALCAR supplementation for treating symptoms of depression [29]. An evidence-based dose of ALCAR ranges from 1,000 – 3,000 mg per day.

The inclusion of stimulant-free pre-workout ingredients like ALCAR, L-tyrosine, and alpha-GPC is how we can keep the caffeine content relatively modest in BULK and LEAN while maintaining the energy and focus benefits users should expect from the best pre-workout supplement.

10. Astragin™

Astragin™  is a water-soluble extract of Panax notoginseng and Astragalus membranaceus two promising adaptogenic herbs with longstanding medicinal use [28]. So, how does this ingredient work?

The constituents in these plants are suggested to selectively increase the absorption of molecules by enhancing intestinal permeability [29]. In other words, Astragin™ helps your body absorb the other ingredients in your pre-workout supplement, making them more effective.

What About Creatine?

Creatine is undoubtedly effective for increasing muscle mass and athletic performance. However, research suggests that caffeine may inhibit the uptake of creatine [30]. Granted, the inhibitory effects of caffeine on creatine absorption are somewhat equivocal.

Regardless, we recommend taking a stand-alone creatine product like Creatine HMB post-workout instead of before training, just to be on the safe side.

Ingredient Summary Table (Quick Reference)

The Best Pre-Workouts for your Goals

Already familiar with key ingredients?

Use the quick selector below to match your goal with a formula that aligns with the science above.

1. Transparent Labs PreSeries BULK: Best for Muscle Building

PreSeries BULK was formulated for muscle growth, muscle pumps, and strength, and each ingredient in this pre-workout formula is backed by scientific and clinical research, and dosed accordingly. The "star players" in BULK are L-citrulline malate, BetaPure™ betaine anhydrous, beta-alanine, alpha-GPC, and caffeine/Infinergy™.

Perhaps the biggest mistake supplement companies make is overloading their pre-workouts with caffeine and harsh stimulants. In the long run, these formulas are not sensible due to rapid induction of drug tolerance (and feelings of adrenal fatigue); it's a slippery slope when you're relying on large doses of caffeine just to get through a workout.

So, BULK instead includes plenty of other "players" that come off the bench when you're pushing through a tough workout, such as testosterone-boosting micronutrients, L-theanine, taurine, and L-tyrosine. These ingredients provide clean, lasting energy without jitters or post-workout crashing.

Highlights:

✅ A full dose of citrulline malate in a 2:1 ratio for extended nitric oxide production and blood flow

✅ Fermented vegan BCAAs

✅ Ample dose of beta-alanine (full clinical dose)

✅ L-theanine + caffeine in a 2:1 ratio

✅ No food dyes, no artificial sweeteners, or flavors

✅ Testosterone support complex (with vitamin D, Zinc, and Boron)

2. Transparent Labs PreSeries LEAN: Best for Weight Loss

If you're after the best pre-workout for weight loss, look no further than PreSeries LEAN. This formula is great regardless if you're doing an intense cardio session or pumping some iron. And being a vegan pre-workout, LEAN is suitable for trying to cut body fat on a plant-based diet.

Highlights: 

✅ Two grams of BCAA 2:1:1 (fermented and vegan) to help prevent muscle breakdown and accelerate recovery

✅ Just enough caffeine, Infinergy™, and theobromine to power through your workouts without untoward effects

✅ A plentiful 6,000 mg dose of citrulline malate (2:1) and 3,500 mg of BetaPure™ betaine for extended nitric oxide production

✅ No food dyes, no artificial sweeteners, or flavors

✅ Added thyroid support complex to promote healthy metabolism and boost energy levels

3. Transparent Labs PreSeries Stim-Free: Best Caffeine Free

Many people wrongly assume that pre-workouts are only good for boosting physical and mental performance through stimulants like caffeine. This is simply not true. In fact, stimulant-free pre-workouts are a great option when you're craving intense muscle pumps and want to avoid the dreaded post-workout crash.

Be sure to read the ingredient section above to dive deeper into the science behind our selections of best stim-free pre-workouts.

Our Preseries STIM-FREE is packed with clinical doses of L-citrulline malate, beta-alanine, BCAAs, betaine, elevATP®, and much more. It's similar to the BULK pre-workout formula, our best pre-workout for muscle gain, but without the caffeine. And with the massive 20+ gram serving size, this is our best caffeine-free pre-workout powder to boost blood flow, enhance muscle pumps, fortify mental focus, and reduce muscle fatigue every time you hit the gym.

Highlights:

✅ A full dose of citrulline malate 2:1 paired with L-norvaline for extended nitric oxide

✅ Clinical doses of non-stimulant pre-workout ingredients, notably L-citrulline, beta-alanine, betaine, L-tyrosine, taurine, and elevATP®

✅ No artificial sweeteners, food dyes, or artificial flavoring

4. Transparent Labs PreSeries BULK BLACK: Best for Pumps

If you’re looking to take your workouts to the next level, check out the newest addition to the Transparent Labs PreSeries, BULK BLACK. With a harder-hitting dose of caffeine than the original BULK formula, BULK BLACK is perfect for stim lovers who want to feel intense muscle pumps and longer lasting lifts in mood, focus, and drive.

Highlights:

✅ Same great science-backed ingredients and clinical doses as the bestselling BULK

✅ 275mg of Caffeine Anhydrous + 30mg Infinergy™, a trademarked caffeine salt of malic acid that prolongs the ergogenic effects of caffeine

✅ No artificial sweeteners, food dyes, or artificial flavoring

Where to Find the Best Pre-Workout Supplements

You should now know what to look for , and what to avoid, when searching for your next pre-workout supplement. The tricky part, for some, is tracking down a single product that provides the best pre-workout ingredients without any of the fluff and filler. 

The good news is we've done the work for you by creating an unmatched lineup of clean, evidence-based pre-workout formulas with full label transparency and no artificial flavors, sweeteners, or colors. Whether you're after the best non-stim pre-workout or best pre-workout for weight loss, we firmly believe we have the best pre-workout supplements for athletes, bodybuilders, beginner trainees, and active individuals that care about what they put in their bodies.

But don't just take our word for it, let the formulas and the results speak for themselves. 

Pre-Workout FAQs

What is the single most reliable pre-workout ingredient?

Citrulline malate is widely used to support nitric oxide, blood flow, and endurance — a strong foundation for both strength and cardio sessions.

How long before training should I take a pre-workout?

Generally 20–40 minutes prior to training for peak effects.

Is a stim-free pre-workout worth it?

Yes. Stim-free formulas like PreSeries Stim Free deliver pumps, focus, and endurance without caffeine, great for evening sessions or stim breaks.

Can I take creatine with my pre-workout?

You can, but some data suggest separating creatine from caffeine. Many lifters take creatine post-workout to keep things simple.

How do I choose the right formula for my goal?

Match your goal to the quick table above: Bulk for muscle gain, Lean for cutting, Stim Free for no caffeine, and Bulk Black for high-stim energy.