A handful of supplements have strong evidence behind them for improving workout performance, recovery, and muscle growth. Most of what you’ll find on store shelves doesn’t clear that bar. The ones worth your money are creatine, protein, caffeine, and possibly beta-alanine or citrulline, depending on your goals. Everything else is either redundant, unproven, or both.
Creatine: The Most Proven Option
Creatine monohydrate is the single most studied and effective supplement for building muscle and gaining strength. It works by increasing your muscles’ stores of a compound that fuels short, intense efforts like lifting weights or sprinting. Supplementation can boost intramuscular creatine levels by as much as 20%, which translates to more reps, more power, and over time, more muscle.
You have two approaches to dosing. A loading phase of 20 grams per day (split into four 5-gram doses) saturates your muscles in about five to seven days. If you’d rather skip the loading, 3 grams per day reaches the same saturation point over roughly 28 days. After that, 3 to 5 grams daily maintains your levels.
Timing doesn’t matter much. Some early research suggested taking creatine after exercise might produce slightly better results than before, but longer studies have found no meaningful difference between the two. Take it whenever it’s convenient, and focus on consistency instead.
Protein: Total Daily Intake Matters Most
Protein powder isn’t magic. It’s simply a convenient way to hit your daily target, which is the real driver of muscle growth. To maximize muscle building, aim for 1.6 to 2.2 grams of protein per kilogram of body weight per day. For a 180-pound (82 kg) person, that works out to roughly 130 to 180 grams daily.
Spreading that intake across at least four meals appears to be ideal. Each meal should contain about 0.4 to 0.55 grams per kilogram of body weight, which lands around 30 to 45 grams per meal for most people. If you’re already hitting these numbers through food, you don’t need a protein supplement at all. Whey, casein, or plant-based blends are all fine options when whole food falls short.
You may have heard you need to slam a protein shake within 30 minutes of your last set. The so-called “anabolic window” is far less important than once believed. Research shows that total daily protein intake is the primary factor in muscle gain, not whether you eat immediately after training. Your next scheduled meal, whether it comes right after your workout or an hour or two later, is sufficient for recovery and growth.
Caffeine: Cheap and Effective
Caffeine is one of the most reliable performance boosters available. It reduces perceived effort, increases alertness, and can meaningfully improve both strength and endurance. The effective dose is 3 to 6 milligrams per kilogram of body weight, taken roughly 30 to 60 minutes before exercise. For a 150-pound person, that’s about 200 to 400 milligrams, or roughly two to four cups of coffee.
Doses above 9 mg/kg don’t produce additional benefits and come with significantly more side effects like jitteriness, nausea, and a racing heart. If you already drink coffee regularly, you may need to sit toward the higher end of the range due to tolerance, but there’s no need to push past 6 mg/kg. A cup of coffee, caffeine pill, or pre-workout drink all deliver the same molecule.
Beta-Alanine: Best for Sustained Efforts
Beta-alanine increases levels of a buffering compound in your muscles that helps neutralize acid buildup during hard efforts. Its benefits are most pronounced during activities lasting one to four minutes: think high-rep sets, circuit training, rowing intervals, or middle-distance running. If your workouts consist mostly of heavy, low-rep lifting with long rest periods, you’re unlikely to notice much difference.
The effective dose is 4 to 6 grams per day, split into smaller doses of 2 grams or less to minimize the harmless but intense tingling sensation many people experience. This isn’t an instant-effect supplement. It takes at least two weeks of daily loading to raise muscle carnosine levels by 20 to 30%, with the more significant increases of 40 to 60% appearing after four weeks. After 10 weeks of consistent use, levels can climb by up to 80%.
Citrulline: Modest Benefits for Soreness
Citrulline malate is commonly marketed as a “pump” supplement that increases blood flow to working muscles. The reality is more nuanced. While citrulline does participate in nitric oxide production, recent research using direct blood flow measurements found that 8 grams taken before exercise had no measurable effect on muscle blood flow or oxygen delivery during leg extensions.
Where citrulline may help is with soreness. One study of 41 men found that 8 grams taken an hour before resistance training reduced muscle soreness by about 40% at both 24 and 48 hours post-exercise, though other studies using 6-gram doses failed to replicate this. If you want to try it, 8 grams about an hour before training is the most commonly used protocol. Consider it a “nice to have” rather than a cornerstone supplement.
Beetroot Juice: For Endurance Athletes
If your training involves sustained aerobic effort (running, cycling, swimming, rowing), beetroot juice concentrate is worth considering. It’s rich in dietary nitrate, which the body converts into nitric oxide to improve oxygen efficiency during exercise. The Australian Institute of Sport classifies it as a proven performance supplement for endurance activities.
The effective dose is 350 to 500 milligrams of nitrate, typically delivered in a concentrated 70 ml beetroot shot, consumed two to three hours before exercise. Taking more than about 700 mg doesn’t produce additional benefits. Some athletes load for several days before competition, taking one dose in the morning and one in the evening for three days leading up to race day. One quirk: avoid mouthwash around the time you take it, because the bacteria in your mouth that convert nitrate into its active form are killed off by antiseptic rinses.
Skip the BCAAs
Branched-chain amino acid supplements remain popular, but the evidence behind them is weak. BCAAs are three of the nine essential amino acids your body needs, and the marketing claim is that they stimulate muscle protein synthesis on their own. They don’t. Building new muscle protein requires all essential amino acids, not just three of them. A comprehensive review found that BCAA supplementation alone actually decreased muscle protein synthesis in the only controlled human studies available, because the remaining amino acids had to be scavenged from existing muscle tissue.
If you’re eating enough total protein, you’re already getting plenty of BCAAs from food. Whey protein, for instance, is naturally about 25% BCAAs. Buying them separately is redundant. If you train in a fasted state and want amino acid coverage, a full essential amino acid (EAA) supplement is a better choice, though simply eating a meal with protein before or after training accomplishes the same thing.
How to Buy Supplements Safely
Dietary supplements aren’t tested for safety or accuracy before they hit shelves. Independent testing has repeatedly found products that contain less of the active ingredient than listed, or that include contaminants not on the label. To protect yourself, look for products certified by one of three major third-party testing organizations: NSF International, the US Pharmacopeial Convention (USP), or ConsumerLab.com. Each has a seal you can look for on the packaging, verifying that the product contains what it claims and is free of harmful contaminants. NSF’s “Certified for Sport” program is particularly important if you compete in drug-tested athletics, as it screens for banned substances.
Start with creatine and adequate protein. Those two cover the vast majority of what supplementation can do for you. Add caffeine if you want a pre-workout boost, and consider beta-alanine or citrulline only after the basics are locked in. Everything beyond that offers diminishing returns.