Written by Dr. Leandro Cordova, Ph.D. — Co-Founder & Formulation Scientist at Proven Science Nutrition Science First. Results Always.
Walk down the pre-workout aisle and you'll find a wall of tubs promising explosive energy, skin-tearing pumps, and laser focus, each with a longer ingredient list and a more aggressive name than the last. Here's what the marketing won't tell you: a pre-workout is only as good as its ingredients — at the doses that actually do something. And most products fall short on exactly that.
So let's cut through it. As a formulation scientist, I'm going to walk you through what the three workhorse pre-workout ingredients actually do, the doses the research supports, why the famous "tingle" is misunderstood, and — most useful of all — how to read a Supplement Facts panel so you can tell a real formula from an expensive placebo.
What a Pre-Workout Is Actually Trying to Do
Strip away the hype and a good pre-workout is chasing three specific, measurable goals:
- More blood flow to working muscle (the "pump," plus oxygen and nutrient delivery).
- More work before fatigue — buffering the acidity that builds up during hard efforts so you can push out more quality reps or hold a hard pace longer.
- More focus and drive — a central-nervous-system lift that makes the session feel easier and sharper.
Three goals, and — conveniently — three well-researched ingredients that each target one of them. Everything else on most labels is, at best, a supporting act. Let's take them in order.
L-Citrulline: Blood Flow and the "Pump"
What it does: L-citrulline is an amino acid that your body converts into arginine, which then feeds the production of nitric oxide — a molecule that relaxes and widens your blood vessels (vasodilation). Wider vessels mean more blood flow to working muscle: more oxygen, more nutrients, and that full, pumped feeling. (Interestingly, supplementing citrulline raises blood arginine more effectively than supplementing arginine itself, which is why good formulas use citrulline.)
The evidence: This isn't just theory. L-citrulline supplementation has been shown to improve oxygen-uptake kinetics and high-intensity exercise performance,[1] and citrulline malate (citrulline bound to malate) increased the number of repetitions athletes could perform and reduced next-day muscle soreness in resistance-trained men.[2]
The dose that works: Research-backed benefits come from roughly 6 grams of L-citrulline, or about 8 grams of citrulline malate — taken before training.[1][2] Here's the catch: a lot of products contain a fraction of that — one or two grams — which lets them print "L-citrulline" on the label without delivering the dose that the studies used. Under-dosed citrulline is one of the most common ways a pre-workout looks impressive and does little.
Beta-Alanine: Buffering Fatigue (and the Real Story on the Tingles)
What it does: Beta-alanine is the ingredient behind that tingly skin sensation — but what it's actually doing is more interesting than the tingle. Once ingested, beta-alanine combines with another amino acid to raise the level of carnosine stored in your muscle. Carnosine acts as a buffer: during hard, sustained efforts your muscles accumulate hydrogen ions and become more acidic, which contributes to fatigue. More carnosine means more buffering capacity, which means you can sustain high-intensity work a little longer before that burn forces you to stop.[3]
The evidence: A meta-analysis found beta-alanine meaningfully improves exercise capacity, with the clearest benefit for efforts lasting roughly one to four minutes[4] — think a hard interval, a tough set taken deep, a 400–1500 m effort. That's its sweet spot.
The dose that works — and why it's different: This is the ingredient people misunderstand most. Beta-alanine works by saturating your muscle carnosine over time, so the effective approach is about 3.2–6.4 grams per day, taken consistently for several weeks — not a single big scoop before you train.[3] In other words, beta-alanine is a daily supplement that happens to be in your pre-workout, much like creatine. One pre-workout serving on training days alone won't fully saturate you; consistency is what delivers the benefit.
The tingle (paresthesia) does not mean it's working
Let's retire this myth. That pins-and-needles, flushing sensation on your face, neck, and hands is called paresthesia, and it happens because beta-alanine briefly binds to nerve receptors in your skin.[3] It is harmless, and — crucially — it is not a measure of effectiveness. The benefit of beta-alanine comes from carnosine you've built up in muscle over weeks, which has nothing to do with how much your skin tingles in the moment. A product that makes you tingle harder isn't working better; it may simply have a large single dose (and the tingle can be reduced by splitting doses or using a sustained-release form). Chasing the tingle is chasing a sensation, not a result.
Caffeine: Focus and Output
What it does: Caffeine is the one ingredient here that delivers an immediate, reliable performance effect. It blocks the brain signals that make exercise feel hard, which lifts focus, drive, and output across almost every kind of training. It's the most proven ergogenic in sports.
Because caffeine deserves its own deep-dive — how much to take, when, why it affects people differently, and how to protect your sleep — I've written one: Caffeine and Performance: How to Use the Most Proven Supplement in Sports Correctly. The short version: the research-backed range is about 3–6 mg per kilogram of body weight, taken 45–60 minutes before training, and more is not better.[5] When you're stacking it inside a pre-workout, the key is simply knowing exactly how much you're getting — which brings us to the real issue.
The core three pre-workout ingredients, what each does, and the research-backed dose
Research-supported ingredients and effective doses; many products under-deliver on these (Bailey et al., 2015; Pérez-Guisado & Jakeman, 2010; Trexler et al., 2015; Guest et al., 2021).
Effective Doses vs. Marketing Doses
Here's the industry's dirty little secret: it's common to include a proven ingredient at a tiny, sub-effective dose purely so it can appear on the label. The practice even has a nickname — "fairy dusting" or "pixie-dusting." A product can legally advertise "Contains L-citrulline and beta-alanine!" while providing a small fraction of the researched amount. You pay for the name on the panel, not the effect in the gym.
This is why the number on the label matters as much as the ingredient. One gram of citrulline is not six. A pinch of beta-alanine in a single scoop is not daily saturation. The ingredient list tells you what's present; only the doses tell you what will work.
Why More Ingredients Isn't a Better Formula
It's tempting to assume the tub with 25 ingredients is more advanced than the one with six. Usually it's the opposite. Fitting that many ingredients into one scoop almost guarantees that most of them are present in token amounts — you simply can't put effective doses of 25 things in a single serving. A long, exotic ingredient list is often a marketing strategy, not a formulation strategy: it looks sophisticated and lets the label make more claims.
A genuinely good formula tends to be simpler: the handful of ingredients with strong evidence, each dosed to match the research, and nothing added just to lengthen the panel. More names on the label is not more results in your training.
How to Read a Supplement Facts Panel Like a Scientist
Here's your practical checklist. Flip any pre-workout around and look for:
- Fully disclosed doses — no "proprietary blend." If the label hides the individual amounts inside a "proprietary blend" or "matrix," you cannot know whether anything is dosed effectively. That opacity is the single biggest red flag, and it exists to hide under-dosing. Demand to see every dose.
- The proven ingredients at real doses. Check the core three: citrulline around 6 g (or ~8 g citrulline malate), beta-alanine around 3.2–6.4 g, and a sensible, stated amount of caffeine.
- A caffeine number you can plan around. You need the exact milligrams to match it to your tolerance and avoid stacking it on top of your coffee and an energy drink.
- Skepticism toward long lists of trace ingredients. A dozen "bonus" actives at tiny doses add cost and claims, not performance.
If a label passes that test — real ingredients, real doses, fully disclosed — you've found a product worth your money. If it hides behind a blend, put it back.
The Standard We're Building Toward
Everything above is exactly why we've taken our time developing PSN's upcoming Pre-Workout. Our entire brand is built on a simple, uncompromising rule: the ingredients that are actually proven to work, at the doses the research supports, with every single amount disclosed on the label — no proprietary blends, ever. That's a harder and more expensive way to build a pre-workout, and it's the only way we're willing to do it. When it launches, you'll be able to hold it to the exact checklist above — because it was built to pass it. (You can read more about that standard on Our Mission.)
The Bottom Line
A pre-workout works when it delivers proven ingredients at effective doses: L-citrulline (~6 g) for blood flow, beta-alanine (~3.2–6.4 g daily, over weeks) for buffering high-intensity fatigue, and a sensible, personalized dose of caffeine for focus and output.[1][2][3][4][5] The tingle isn't a measure of anything, more ingredients isn't better, and a proprietary blend is a reason to walk away. Learn to read the panel, insist on disclosed doses, and you'll never overpay for fairy dust again.
Science first. Results always.
Build Your Whole Plan
A pre-workout is a small piece of the picture — training, fueling, and recovery are the rest. Our free Nutritional & Supplement Guide is a strong, science-first place to start, and Fit by Mi offers personalized coaching if you want a plan built around you.
Frequently Asked Questions
What actually makes a pre-workout work? Proven ingredients at effective doses — not a long label or a strong tingle. The three with the best evidence are L-citrulline (blood flow and pump), beta-alanine (buffers the acidity that causes high-intensity fatigue), and caffeine (focus and output).[1][3][5] If those are present at research-backed amounts and fully disclosed, the product can work; if they're under-dosed or hidden in a blend, it likely won't.
What does L-citrulline do in a pre-workout? It raises nitric oxide, which widens blood vessels and increases blood flow to working muscle — more oxygen, more nutrients, and a better "pump." It's been shown to improve high-intensity performance and increase training reps.[1][2] Look for about 6 g of L-citrulline (or ~8 g of citrulline malate); many products use far less.
What does beta-alanine do, and why does it make me tingle? Beta-alanine raises muscle carnosine, which buffers the acid buildup that fatigues you during hard, 1–4-minute efforts.[3][4] The tingling (paresthesia) is a harmless skin sensation from beta-alanine binding nerve receptors — it is not a sign the product is working. It works by saturating your muscles over weeks of daily use (about 3.2–6.4 g/day), not from a single pre-workout scoop.
Does the tingling feeling mean the pre-workout is effective? No. The tingle (paresthesia) is just a temporary nerve sensation from beta-alanine and is unrelated to its benefit, which comes from carnosine built up over weeks.[3] A stronger tingle doesn't mean a better product — it often just means a large single dose.
How do I know if a pre-workout is dosed properly? Read the Supplement Facts panel. Avoid anything that hides amounts in a "proprietary blend," and check that the core ingredients hit effective doses: citrulline ~6 g (or ~8 g citrulline malate), beta-alanine ~3.2–6.4 g, and a clearly stated caffeine amount.[1][3][5] Fully disclosed doses are the sign of a company with nothing to hide.
Is a pre-workout with more ingredients better? Usually not. You can't fit effective doses of 20-plus ingredients into one scoop, so long lists almost always mean most ingredients are present in token amounts. A simpler formula with the proven ingredients at real, disclosed doses beats a crowded one nearly every time.
Written by Dr. Leandro Cordova, Ph.D., Co-Founder and Formulation Scientist at Proven Science Nutrition. With a Ph.D. and 15+ years in product development, Leo leads the development of every PSN formula — built on peer-reviewed science, with no proprietary blends.
Questions about our formulas or the research behind them? Reach us at contact@psnutrition.net.
*This article is for educational purposes only and is not medical advice. Pre-workout supplements commonly contain caffeine and other stimulants and are not appropriate for everyone. Consult a qualified healthcare professional before use if you are pregnant or breastfeeding, take medication, or have a heart, blood pressure, or other medical condition.
References
- Bailey SJ, Blackwell JR, Lord T, Vanhatalo A, Winyard PG, Jones AM. l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans. Journal of Applied Physiology. 2015;119(4):385–395. doi:10.1152/japplphysiol.00192.2014
- Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning Research. 2010;24(5):1215–1222. doi:10.1519/JSC.0b013e3181cb28e0
- Trexler ET, Smith-Ryan AE, Stout JR, et al. International society of sports nutrition position stand: Beta-Alanine. Journal of the International Society of Sports Nutrition. 2015;12:30. doi:10.1186/s12970-015-0090-y
- Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012;43(1):25–37. doi:10.1007/s00726-011-1200-z
- Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition. 2021;18(1):1. doi:10.1186/s12970-020-00383-4
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
