Workout Supplements Guide: What’s (Really) Worth Buying?

Discover the 3 workout supplements known to reliably promote muscle growth and/or gym performance, plus how to use them for maximum efficacy.

Workout Supplements Guide: What’s (Really) Worth Buying?

Nobody likes spending money on things that don’t work. 

E.g., skincare that breaks you out instead of giving you a “refreshed and glowy complexion” as advertised. Supposed no-questions-asked lifetime warranties that are only honored after, well, many questions asked.

And, of course, workout supplements. 

So, to prevent you from wasting hard-earned dough in this economic climate (sigh), this article covers:

The 3 workout supplements known to reliably promote muscle growth and/or performance in the gym and
How to use them — from dosage to timing to pairing with other ingredients — for maximum efficacy 

In between, you’ll also get answers to spicy, spicy questions like, “Are pre-workouts just glorified overly expensive caffeine powders?” 

Speaking of caffeine …

#1: Caffeine

Given caffeine’s well-known and loved stimulant property (it’s the most widely consumed psychoactive substance in the world, after all), seeing it make the rather exclusive list of workout supplements worth buying shouldn’t be a surprise. 

Scientists still can’t agree on how, exactly, caffeine improves exercise performance. 

Some believe it comes down entirely to its stimulating effect on the nervous system. Some think caffeine boosts muscle production force. Then, there are those who theorize that it could simply be the good ol’ placebo effect at play

But the one thing researchers (generally) see eye to eye on? 

Caffeine is one of the good workout supplements that work.

A large body of evidence says so:

Aerobic exercise

Caffeine has been shown to improve endurance by 2% to 4% across several sports involving aerobic endurance, including cycling, running, cross-country skiing, and swimming.

A 2020 meta-analysis of 7 studies published in Nutrients, for instance, found that caffeine helped competitive rowers improve their time on a 2,000 m row by about 4 seconds.

That’s a lot, considering that the difference between getting a medal and not in most endurance sports is in milliseconds

Anaerobic exercise

Unlike endurance-type sports, findings about caffeine’s effects on muscular strength are less wow-worthy.

For example, while most studies show caffeine enhances strength, the effects are relatively small — ranging from 2% to 7%.

So if your 1RM for the barbell back squat is 70 kg, caffeine could potentially help you slap on an additional 1.4 kg to 4.9 kg on the barbell. That’s arguably pretty … meh.

Caffeine also appears to have a larger effect on lower body strength than upper body strength

How to use caffeine 

Hmm, OK. Does that mean you should only take caffeine on cardio days? You could, but it’s impractical and/or unnecessary for 2 reasons: 

  1. Chances are, you, like most people, do strength training and cardio in the same workout session. So, unless you get all anal about your caffeine consumption timing (e.g., take it while you’re halfway through deadlifting and 20 minutes before your choice of cardio), you’d likely have some caffeine in your blood when strength training. 
  2. While caffeine’s effect on muscular strength is small, it’s ultimately positive. It’s more likely to improve your lifting performance than harm it. 

That said, an important disclaimer: there is great inter-individuality in caffeine response, depending on factors like genetics, sex, hormonal activity, and even diet.

That means everyone responds differently to caffeine.

So while caffeine is one of the most science-backed workout supplements around, you’ll still have to experiment with it to see whether it works for you

But how, when you don’t even know the “correct” caffeine dosage to try?

Studies suggest that 5 to 6 mg of caffeine per kilogram of body weight appears to be the “sweet spot” for maximizing performance while minimizing unwanted side effects, such as:

  • Anxiety
  • Irritability
  • Gastrointestinal discomfort
  • Jitteriness
  • Sleep disruptions*. 

If you weigh 70 kg, that’ll translate to an “ideal” caffeine dosage of 350 to 420 mg. For reference, 1 cup of brewed coffee contains about 95 mg of caffeine on average. 

*Tip: if caffeine worsens your sleep, go with a lower dosage (3 mg per kg of body weight) and take it as early in your day as possible.

In most cases, trading some of caffeine’s performance-enhancing effects for more good-quality sleep would help you see better muscle growth in the long term.

Um, what about habituation?

Or, in other words, does caffeine’s performance-enhancing effects diminish or even disappear over time?

To be honest, the research is unclear. 

A 2022 meta-analysis of 60 studies published in Sports Medicine concluded that caffeine’s ability to give an exercising edge does not decrease with habitual consumption. 

But while meta-analyses are often considered the “gold standard” for scientific evidence, there is 1 issue with this particular meta-analysis that throws its finding into question. 

The studies determined habitual caffeine intake based on self-reported habits. 

What’s wrong with that? Well, can you remember how much caffeine you had 2 days ago? Or what about a week before? We don’t know about you, but for us:

In contrast, a 2019 randomized controlled trial published in PLoS One investigated caffeine habituation and exercise performance from a truly experimental perspective by controlling the exact caffeine dosage each of the participants took. 

Here’s what the researchers found: the magnitude of caffeine’s performance-enhancing effects decreased with repeated use over a 20-day period.

Shoot. What now? Right now, you have 2 broad options:

Ignore caffeine habituation concerns (diminishing results don’t mean the same thing as disappearing results, after all)
Try to avoid habituation by “saving” your caffeine consumption for your toughest workouts

Are pre-workouts worth buying?

It’s no secret that the main ingredient in most pre-workouts is caffeine. 

Obviously, a natural question to follow in this workout supplements guide would be:

“Are pre-workouts just … overpriced caffeine?”

To answer that, we’ll have to look into 2 things:

  1. The purpose of taking a pre-workout: Enhance energy, focus, and performance during exercise
  2. Ingredients a typical pre-workout contains: Caffeine, creatine, beta-alanine, and a nitric oxide booster (e.g., nitrate and citrulline malate)

At this point, we know that caffeine definitely ticks all 3 boxes of what a pre-workout is supposed to do.

But what we don’t know is whether we could say the same for the other ingredients — i.e., creatine, beta-alanine, and nitric oxide boosters. 

So let’s find out.


While creatine is one of the few effective workout supplements, it doesn’t offer “instant” performance-enhancing effects. 

It needs to build up to a particular concentration in your body before it works. (We’ll cover more details in a bit!) 

In that sense, then, creatine doesn’t necessarily have to be consumed in a pre-workout supplement.


High-intensity exercise forces your body to convert glucose to ATP (energy) via anaerobic glycolysis

The resulting byproducts, such as hydrogen ions, could lower intramuscular cellular pH (i.e., creating a more acidic environment) over time; and acidosis is linked to neuromuscular fatigue. 

And what does beta-alanine have to do with all this? 

Turns out, it increases intramuscular carnosine, which attenuates acidosis. In other words: it delays fatigue. 

Ah, so beta-alanine works, right? Yes. 

But only if you’re training in a very specific style that truly taxes your glycolytic energy system and causes pronounced acidosis.

E.g., CrossFit workouts and rep ranges > 20 reps per set. 

Otherwise, typical cardio activities and hypertrophy-focused resistance training involving 6 to 15 reps with plenty of rest, where you rely on aerobic (i.e., oxygen-dependent) respiration, are unlikely to benefit from beta-alanine supplementation.

Nitric oxide boosters 

Because nitric oxide is a vasodilator, many believe that nitric oxide-boosting workout supplements improve workout performance by increasing blood flow.

In reality, though, it’s unlikely that the delivery or clearance of blood is a critically limiting factor for exercise performance.

While scientists are still unsure of how nitric oxide works, a leading theory is that it enhances the contractile function of muscle by regulating calcium release and sensitivity.

Wait a minute. So nitric oxide — and, in the same vein (couldn’t resist the pun!), nitric oxide boosting workout supplements — work?

Research suggests a tentative yes.

Let’s look at 2 popular types of nitric oxide boosters you can easily find on the market: nitrate and citrulline.

Nitrate workout supplements

  • 2016 study published in the Journal of Strength and Conditioning Research: Participants were able to complete significantly more bench press reps in a series of 3 sets to failure at 60% of 1RM after 6 days of beetroot juice supplementation (400 mg of nitrate daily).
  • 2020 study published in the Journal of Strength and Conditioning Research: A single dose of beetroot juice supplementation (400 mg of nitrate) significantly enhanced bench press power, bar velocity, and reps to failure at 70% of 1RM in comparison to a placebo.

Hmm. Seems like nitrate works well. So, what’s with the tentativeness? 

Well, the main reservation is that it appears you don’t need nitrate workout supplements.

You’d likely do fine with just dietary sources of nitrate (e.g., beetroot juice). 

FYI, nitrate-rich food sources include radish (625 mg/100 g), beetroot (495 mg/100 g), lettuce (365 mg/100 g), celery (261 mg/100 g), and spinach (up to 387 mg/100 g).

Takeaway? Eat your leafy greens and show beetroots some love!

Citrulline workout supplements

Research findings on the efficacy of citrulline workout supplements have been a mixed bag. 

Two meta-analyses (a 2019 one published in Sports Medicine and a 2021 one published in the International Journal of Sport Nutrition and Exercise Metabolism) have indicated that citrulline can acutely enhance strength endurance (e.g., number of reps performed before reaching failure). 

But there have also been numerous isolated studies reporting null effects

Since we cannot draw any conclusions from citrulline-only studies, perhaps a productive way to tease out citrulline workout supplements’ efficacy would be by asking this: “Would I see additional workout benefits than if I were to only take caffeine?”

Lucky us, because that’s the exact question the researchers of a 2023 study published in the European Journal of Nutrition answered.

They had 35 resistance-trained participants complete 4 testing sessions to assess the impact of 4 different supplement conditions:

  1. Caffeine (5 mg/kg of body weight)
  2. Citrulline malate (12 g, with a 2:1 citrulline-to-malate ratio)
  3. Caffeine + citrulline malate (a combination of #1 and #2)
  4. Placebo

Without diving into too much detail, here are the 3 key, relevant highlights from the paper for our topic on hand:

Caffeine + citrulline increased bench press reps to failure more than caffeine only (+12% versus +9%, respectively)
Caffeine + citrulline did not increase squat reps to failure more than caffeine only (both came in at around +18%)
The researchers noted 7 adverse events, all of which were reported in the caffeine + citrulline condition (3 = headaches, 3 = nausea, and 1 = dizziness)

All in all, it appears that citrulline workout supplements may offer additive strength endurance benefits to caffeine — but only on the bench press. And not without the risk of side effects. 

Weigh the pros and cons yourself

OK, whew. Time for a summary of the ingredients you’d typically find in pre-workout supplements in addition to caffeine:

  • Creatine: Doesn’t offer instant workout benefits; more details to follow in a bit.
  • Beta-alanine: May offer benefits only for high-intensity activities (i.e., not that applicable for the “traditional” resistance training style, where you get 2 to 3 minutes of rest between sets); research suggests a daily dose of 3.2 to 6.4 g.
  • Nitrate: May increase strength-endurance (e.g., number of reps before failure); research suggests a daily dose of 400 to 800 mg, which you could easily meet via dietary sources.
  • Citrulline: Pairing caffeine and citrulline may offer additional exercise benefits than caffeine alone, but not across all exercises, plus the combination could cause side effects, like nausea; research suggests a daily dose of 8 to 12 g.

So, back to our original question. Are pre-workout supplements worth buying?

Only you can answer that by weighing the pros and cons yourself.

Things to consider include:

  • Can you get enough caffeine (3 to 6 mg/kg of body weight) through your usual sources, such as coffee?
  • Would your training style truly benefit from beta-alanine supplementation?
  • Does the convenience of all-in-one pre-workout supplements appeal to you? Even if they’re often more expensive than if you were to buy each individual ingredient separately?

Think about it carefully, and you’ll soon have your answer.

#2: Creatine 

To understand why creatine is one of the few effective workout supplements, you’ll first need to know what it is and what it does. 

Creatine is an amino acid derivative your body naturally produces, stores (as phosphocreatine), and uses as an indirect energy source.

(🧑‍🔬Warning, sciencey bit: phosphocreatine “donates” a phosphate group to adenosine diphosphate to form adenosine triphosphate, i.e., ATP.)

Now, under the beta-alanine section, we mentioned that your body can produce ATP (i.e., energy) via 2 pathways: aerobic respiration and anaerobic glycolysis. 

In truth, though, there’s a third energy pathway known as the ATP-phosphocreatine system.

Here’s how you could make sense of each pathway:

Aerobic respiration

Slow rate of ATP production; your body predominantly relies on this during longer-duration, lower-intensity activities. E.g., steady-state cardio.
Anaerobic glycolysis

Rapid rate of ATP production; your body typically uses this system during activities requiring large bursts of energy over somewhat longer periods (30 seconds to 3 minutes, max). E.g., HIIT.
ATP-phosphocreatine system

Almost instantaneous rate of ATP production; your body usually uses this system during high-intensity movements that last between 5 to 10 seconds. E.g., tough working sets or a 1RM attempt.

Logically speaking, creatine supplementation should increase your phosphocreatine stores — and, thus, your body’s capacity for short, high-intensity activities. But does that theory pan out in reality? 

Research says yes.

More specifically, studies show that creatine supplementation could spike your phosphocreatine stores by 10% to 40%, resulting in:

  • Enhanced performance and strength in short-duration, maximal-intensity exercises (as measured by 1RM, muscular power, number of repetitions, muscular endurance, speed, and total force).
  • Increased lean body mass via 2 mechanisms. First, in the short-term, stored creatine draws water into muscles, potentially causing a “water weight gain” of anywhere between 0.45 to 1.36 kg. Second, since creatine enables a higher training volume, that’ll likely translate to better muscle growth outcomes over time.

How to use creatine

Great. So creatine workout supplements work. 

But what type of creatine should you choose — creatine monohydrate, creatine anhydrous, creatine hydrochloride, etc.?

The researchers of this 2021 systematic review published in The Journal of Strength and Conditioning Research did us all a huge, huge favor by analyzing the efficacy of 8 different creatine types. 

Guess what they found?

Curveball: all 8 types worked equally well at boosting phosphocreatine stores. 

Thankfully, the researchers also broke down the cost per serving for each creatine type and found creatine monohydrate the cheapest among all (US$0.19 per 5 g serving). 

FYI, buffered creatine worked out to be the most expensive of the lot, coming in at a whopping US$1.51 per 5 g serving. That’s nearly 8x the cost of creatine monohydrate!


Stick with creatine monohydrate. It’s the cheapest option and, perhaps more importantly, just as effective as other creatine alternatives.


A common dosing strategy for creatine workout supplements is a straightforward 3 g daily.

However, this can mean you’ll experience creatine’s full benefits only after 3 to 4 weeks (which is the point you fully saturate your muscles’ phosphocreatine stores). If you’d like to shorten the timeline to full saturation in a week, an alternative creatine protocol would be to:

  1. Take 20 g of creatine daily for 7 days, then
  2. Drop down to the “maintenance dose” of 3 g daily for however long you’re on creatine workout supplements

That said, this fast-and-furious loading strategy isn’t without its downsides.

Taking so much creatine (20 g) at once is associated with digestive distress (e.g., bloating, stomach cramping, and diarrhea).

But, on the bright side, the chances of you sharting appear lower if you space out your 20 g into multiple doses throughout the day.

E.g., 4 x 5 g of creatine every 3 hours.

Any side effects you should know?

Two of the most serious side effects creatine workout supplements allegedly cause? 

Hair loss and kidney damage — which, fortunately, aren’t substantiated by credible, high-quality studies.

Let’s briefly look at each.

Hair loss 

A 2009 study published in the Clinical Journal of Sports Medicine found that creatine supplementation seemed to increase participants’ serum DHT levels and DHT-to-testosterone ratios. 

For the uninitiated, DHT is a hormone that’s been linked to androgenic alopecia (previously known as “male pattern baldness”). 

At first glance, this can appear concerning … until you realize that:

  1. Other studies — 12 so far, but who’s keeping count? — have generally failed to replicate the finding.
  2. The study noted a decrease in DHT levels in the placebo phase; that’s sus AF because why would a placebo affect DHT levels?
  3. A 2018 review published in Molecular and Cellular Endocrinology says, “The unwanted androgen metabolism [i.e., the conversion of testosterone to DHT] at the hair follicle is the major factor in the pathogenesis of androgenic alopecia.” Meaning? Serum DHT levels have little, if not nothing, to do with hair loss.
Bottom line: there just isn’t much evidence creatine causes hair loss (phew).
Kidney damage

Your body breaks creatine phosphate down into creatinine.

Now, since creatine supplementation increases your phosphocreatine stores, your creatinine levels would naturally rise — and this complicates things. 

How so? Because elevated creatinine levels are a sign of impaired kidney function.

Fortunately, though, a large body of scientific evidence suggests that beyond a harmless increase in creatinine levels, creatine workout supplements are unlikely to cause any adverse effects on the kidneys in people with healthy kidneys and people with kidney disease.

Does this mean creatine supplementation is 100% safe?

No, we can’t say that for sure.

You may have underlying medical conditions (known and unknown) that could affect how safe creatine is for you. So, as always, please consult your primary healthcare provider before starting a new supplement. 

They’ll have the 1) medical expertise and 2) access to your health history needed to advise you.

Digestive distress

Taking too much creatine in one go isn’t the only scenario you’d experience digestive distress. 

While scientists still aren’t sure why, it appears taking creatine and caffeine together also bumps up the likelihood that you’d experience gastrointestinal discomfort.

Thankfully, circumventing this is pretty easy.

Space out your caffeine and creatine intake appropriately. 

E.g., take your caffeine at 9 am, then creatine at, say, 3 pm. 

Are creatine supplements worth buying?

Based on everything we’ve learned so far, it’ll have to be a yes. 

Creatine is one of the most well-researched supplements and has a long safety record. 

#3: Protein powder 

TBH, there’s nothing much to say about protein powder — the last item on our list of effective workout supplements.

So this section will be short and sweet. 

Now, if you lift weights and wish to maximize muscle growth, you probably already know 2 things:

Eating enough protein is necessary for hypertrophy and
Getting enough protein from your diet consistently can be a challenge

Let’s say you weigh about 60 kg and are aiming to get 90 g of protein daily.

For reference, 100 g of cooked chicken breast (one of the most protein-rich sources around) provides 31 g of protein. And if you’re on a plant-based diet, 100 g of cooked tofu provides 9 g of protein.

Chances are, unless you intentionally include a protein source during every meal, you’ll fall short of your protein goals. 

This is where protein powders shine. 

They’re a quick, convenient, and relatively inexpensive way for you to “plug the gap” in your protein intake. 

That said, not all protein powders are made equal. 

Here are 2 tips that’ll help you choose one that’s best suited for your needs:

  • Go for complete protein sources: Or, in other words, protein powders that contain all 9 essential amino acids. Most animal-derived protein powders (e.g., casein and whey) will fulfill this condition. Plant-based protein powders are generally trickier, but you’d do fine by either going for soy/pea protein powders or protein powders formulated with a blend of different plant-based proteins. 
  • Take your calorie budget into consideration: Certain protein powders can contain more carbohydrates and fats per 1 gram of protein than others. E.g., whey concentrate versus isolate. And while carb and fat-rich (relatively so) protein powders tend to offer a creamier mouthfeel and taste better, they can jack up your calorie intake by quite a bit. So, that’s something you’ll have to be mindful of when choosing protein powders. 

Are protein powder supplements worth buying?

If they help meet your daily protein requirements and give you more wiggle room in your diet, yes!

But if you’re already getting enough protein (and love eating that way), there’s no need for it.

Do you need workout supplements?

No, you don’t need workout supplements. 

You can think of it this way: of all the things that’ll help you make significant progress in your muscle-building/fitness journey, workout supplements should always be of lower priority than optimizing your nutrition and training.