A handful of workout supplements have strong evidence behind them, while most of the industry runs on marketing. Creatine monohydrate, caffeine, citrulline, protein, and beta-alanine consistently show real performance benefits in controlled studies. Everything else falls somewhere between “maybe helpful” and “total waste of money.” Here’s what actually works, how much to take, and what you can skip.
Creatine Monohydrate
Creatine is the single most studied and consistently effective supplement for building strength and muscle. It works by topping off your muscles’ short-term energy reserves, which means more power during heavy lifts, sprints, and any explosive effort lasting under about 30 seconds. Over time, that extra output in the gym adds up to more muscle and strength gains than training alone.
The standard dose is 3 to 5 grams per day, every day, regardless of whether you train that day. Timing doesn’t matter much. You can mix it into water, a shake, or coffee. Some people do a “loading phase” of 20 grams per day for a week to saturate their muscles faster, but taking 5 grams daily gets you to the same place within about three to four weeks. Creatine also appears to speed up muscle recovery after hard sessions and may help preserve muscle mass as you age. Monohydrate is the form with the most research behind it, and it’s also the cheapest. Fancier versions like creatine hydrochloride or buffered creatine haven’t shown meaningful advantages.
Caffeine
Caffeine improves both endurance and high-intensity performance by lowering your perception of effort and increasing alertness. It works for running, cycling, lifting, and pretty much any physical activity where fatigue is a limiting factor.
The performance-enhancing dose is 3 to 6 milligrams per kilogram of body weight, taken about 30 to 60 minutes before training. For a 180-pound (82 kg) person, that’s roughly 250 to 490 milligrams. A standard cup of coffee has about 95 milligrams, so you’d need two to five cups’ worth depending on your size and sensitivity. Going above 6 mg/kg doesn’t improve performance further and increases the risk of jitteriness, a racing heart, and stomach issues.
You can get your dose from coffee, caffeine pills, or a pre-workout powder. Caffeine pills are the easiest way to control your exact intake. If you’re a daily coffee drinker, you’ll still get a performance boost, but it may be slightly blunted compared to someone who rarely uses caffeine. Cycling off for a week or two can restore full sensitivity.
Citrulline
Citrulline (usually sold as citrulline malate) boosts nitric oxide production, which widens blood vessels and improves blood flow to working muscles. The practical result: you can squeeze out a few more reps per set. A meta-analysis of strength training studies found that 6 to 8 grams of citrulline malate taken 40 to 60 minutes before exercise increased total repetitions by about 6% compared to a placebo. That’s a modest but real effect that compounds over weeks of training.
Citrulline also appears to reduce post-workout muscle soreness and perceived exertion, which can help you recover faster between sessions. The effective dose is 6 to 8 grams of citrulline malate, or 3 to 4 grams of pure L-citrulline. Many pre-workout formulas include citrulline, but often at doses well below 6 grams. Check the label and supplement with extra if needed.
Beta-Alanine
Beta-alanine buffers acid buildup in muscles during sustained high-intensity work, the kind of burn you feel during a long set of squats, a 400-meter sprint, or a rowing interval. It’s most useful for efforts lasting roughly one to four minutes, where that acid accumulation is a primary limiter.
The effective daily dose ranges from 3.2 to 6.4 grams. The catch: beta-alanine is famous for causing paresthesia, a harmless but sometimes intense tingling sensation in the face, neck, and hands. This tends to kick in at doses above about 40 milligrams per kilogram of body weight taken at once. Splitting your daily dose into smaller portions of 0.8 to 1.6 grams every three to four hours avoids the tingling while still building up the same muscle stores over time. Beta-alanine needs to accumulate in your muscles over two to four weeks of daily use before you notice performance benefits, so it’s not an “only on training days” supplement.
Protein Supplements
Protein powder isn’t magic, but it solves a practical problem: most people struggle to eat enough protein from whole food alone, especially at the 0.7 to 1.0 grams per pound of body weight that active people benefit from. Whey protein is the most popular option because it digests quickly and is rich in leucine, the amino acid that acts as the primary trigger for muscle building. Research suggests you need roughly 2.5 to 3 grams of leucine per meal to fully activate muscle protein synthesis, and a 25 to 30 gram serving of whey typically delivers that amount.
Casein protein digests much more slowly, which makes it useful in a different context. Taking 40 to 48 grams of casein about 30 minutes before bed, particularly after an evening training session, supports overnight muscle recovery by providing a sustained trickle of amino acids while you sleep. You don’t need both whey and casein. Whey around workouts and casein before bed is a reasonable approach if you want to optimize, but hitting your total daily protein target matters far more than any specific timing strategy.
EAAs vs. BCAAs
Branched-chain amino acids (BCAAs) were hugely popular for years, but the evidence has shifted. BCAAs contain only three of the nine essential amino acids your body needs, and your muscles can’t fully build new protein without all nine present. Essential amino acid (EAA) supplements include all nine and are significantly more effective at stimulating muscle growth. If you’re already eating enough protein or using whey, you likely don’t need either supplement. But if you train fasted or need something light during a workout, EAAs are the better choice over BCAAs.
Electrolytes for Longer Sessions
If your workouts last over an hour, especially in heat, plain water may not be enough. You lose sodium, potassium, magnesium, and chloride through sweat, and replacing only water without electrolytes can dilute what’s left in your bloodstream. Sports scientists generally recommend a sodium-to-potassium ratio between 2:1 and 4:1 for endurance activities. Sodium is the priority because it’s lost in the highest concentration through sweat and plays the biggest role in fluid retention.
For sessions under an hour at moderate intensity, water is fine. You don’t need an electrolyte supplement for a 45-minute lifting session in an air-conditioned gym. But for long runs, outdoor training in summer, or two-a-day sessions, an electrolyte mix helps maintain performance and prevents cramping. Look for products that list sodium content clearly rather than hiding behind proprietary blends.
Tart Cherry Juice for Recovery
Tart cherry juice is one of the few “natural” recovery supplements with legitimate research behind it. The typical protocol used in studies involves drinking the equivalent of about 50 to 60 tart cherries per serving, twice a day (morning and evening), starting five to seven days before a hard event or training block and continuing for two days after. Marathon runners following this approach showed reduced markers of muscle damage and inflammation compared to those drinking a placebo.
This isn’t something you need for everyday training. It’s most useful around a competition, a particularly brutal training week, or when you’re stacking hard sessions close together. Concentrated tart cherry supplements in capsule form exist, though most studies used juice blends.
How to Avoid Contaminated Supplements
The supplement industry is loosely regulated, and independent testing has repeatedly found products containing ingredients not listed on the label, including substances banned in competitive sports. If this matters to you, look for third-party certifications. NSF Certified for Sport and Informed Sport are the most rigorous. Informed Sport tests every batch for banned substances, while the related Informed Choice certification only tests randomly selected batches. Products without any third-party certification, even those made in facilities following good manufacturing practices, offer no guarantees about what’s actually inside.
Even if you’re not a competitive athlete, third-party testing is a useful proxy for overall product quality. Companies willing to pay for independent verification tend to be more transparent about their formulations in general.
What You Can Probably Skip
Testosterone boosters, fat burners, glutamine, CLA, and most “proprietary blend” pre-workouts have weak or nonexistent evidence for healthy adults who train regularly. Testosterone boosters sold over the counter don’t meaningfully raise testosterone levels. Fat burners are mostly caffeine with extra ingredients that add cost without adding results. Glutamine has benefits for gut health and immune function in specific medical contexts, but doesn’t improve muscle growth or recovery in well-nourished people.
The supplements that work are straightforward, well-researched, and relatively cheap. Creatine, caffeine, citrulline, protein, and beta-alanine cover the vast majority of what supplementation can realistically do for your training. Get those right before spending money on anything else.