The Complete Pre-Workout Guide: What It Does, How & When to Take It

Pre-workout is one of the most popular supplements in the gym, and one of the most misunderstood. What does it actually do? How much caffeine is in it, when should you take it and is it bad for you? In this guide we cover everything you need to know: what pre-workout is, which ingredients do the work, how and when to take it, and how to choose the best pre-workout for your training. Whether you've just opened your first tub or you're still comparing formulas, you'll find your answers here.

What Is Pre-Workout?

In its broadest sense, anything you consume before a workout is a pre-workout. That could be a cup of coffee, a carbohydrate-rich meal or a specific supplement. In the fitness world, people usually mean the latter: a powdered formula with several active ingredients, mixed with water and taken shortly before training.

Most pre-workouts are built around caffeine, combined with amino acids such as L-citrulline and beta-alanine, plus vitamins, minerals and other ingredients. You'll also hear them called pre-workout boosters or training boosters. The idea is simple: help you start your session switched on, focused and ready to work.

What Does Pre-Workout Do?

Every formula is different and everyone reacts to it in their own way, but these are the effects most people notice after taking a pre-workout:

Let's keep expectations realistic, though. You won't lift an extra 20kg just by taking a scoop of pre-workout. Progress comes from consistent training, good nutrition and enough rest, and a pre-workout doesn't replace any of those. What it can do is help you show up focused on the days you need it, whether you're stuck at a plateau or just starting out and want to stay locked in during your session.

What Is in Pre-Workout? The Key Ingredients Explained

There are loads of possible ingredients, combinations and doses, but most pre-workouts are built from the same core. Here's what you'll find on the label and why it's there.

Caffeine

Caffeine is the most popular pre-workout ingredient for good reason. It's the world's most widely used stimulant, and the main reason you feel more awake after your pre-workout. How much a pre-workout contains, and how much is too much, is covered in the next section.

L-citrulline and L-arginine

Both are amino acids and precursors of nitric oxide, and they're behind the "pump" many lifters look for in a pre-workout. Citrulline is the one you'll see most in modern formulas, often in large doses: Perfection Pre-Workout contains 9,000mg per serving and the Pre-Workout Double Shot 4,000mg per bottle.

Beta-alanine

Beta-alanine is a naturally occurring amino acid and a regular in pre-workouts built for intense, high-volume training. It's also the ingredient behind the tingling feeling many people notice after their pre-workout, which we explain further down.

Creatine

A daily intake of 3g of creatine increases physical performance in successive bursts of short-term, high-intensity exercise. Some pre-workouts contain creatine, but usually less than the full 3g, so many people take it separately as well. Check out our Creatine 101 article for the full lowdown.

B-vitamins and magnesium

B-vitamins such as B2, B3 and B12 contribute to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. Magnesium also contributes to the reduction of tiredness and fatigue, as well as to normal muscle function. That's why you'll find them in many pre-workouts.

Brainberry®

Brainberry® is a natural, stimulant-free aronia berry extract developed in Maastricht and researched with Maastricht University, and one of the ingredients that makes Perfection Pre-Workout stand out. Aronia berries are naturally deep red, which is also why some Perfection Pre-Workout flavours, like White Energy, turn a surprising shade of red once mixed. Nothing to worry about: that's simply the berry doing its thing. Read the full story in our Brainberry® and aronia deep dive.

How Much Caffeine Is in Pre-Workout?

Most pre-workouts contain between 100mg and 325mg of caffeine per serving. That's roughly the same as one to four cups of coffee. The amount is always listed on the label, and it applies to one full serving: take half a scoop and you get half the caffeine.

Looking for the pre-workout with the most caffeine? In our range that's Perfection Pre-Workout, and whether a full serving suits you depends on your body weight and on how used to caffeine you are. One serving is 2 scoops, so 1 scoop gives you 160mg. But more isn't automatically better. Healthy adults can safely have up to 400mg of caffeine a day from all sources, while the amount you can take at once depends on your body weight. Your morning coffee, tea and energy drinks all count towards that total. Want to know more about how caffeine works in your body? Read our guide on what caffeine does to your body.

How Much Caffeine Can You Take at Once? It Depends on Your Body Weight

You'll often read that 200mg of caffeine at once is safe. That figure comes from the European Food Safety Authority (EFSA) and is based on an adult of 70kg: the guideline behind it is about 3mg of caffeine per kg of body weight. So the right amount for you depends on your weight, and on how used to caffeine you are.

For Perfection Pre-Workout (160mg of caffeine per scoop), that means:

• 2 scoops (320mg) if you weigh around 100kg.
• 1 scoop (160mg) if you weigh around 60kg.

Prefer a lower dose in a handy format? The Pre-Workout Double Shot contains 160mg of caffeine per 100ml bottle. That's two servings of 50ml with 80mg each, which is why it's called a double shot: take half a bottle for a lighter session, or the whole bottle when you want more.

First time using a pre-workout, or not used to caffeine? Then start with half a serving, whichever pre-workout you choose: 1 scoop of Perfection Pre-Workout or half a bottle of the Pre-Workout Double Shot. See how your body reacts, and only build up once you know it suits you.

Your daily total is a separate limit: healthy adults can have up to 400mg of caffeine a day from all sources. A morning coffee (around 90mg) plus 2 scoops of Perfection Pre-Workout (320mg) comes to 410mg, just over that limit. Take 1 scoop instead, or skip the coffee on training days. Pregnant or breastfeeding? Then the advice is a maximum of 200mg a day.

Browse all pre-workouts with caffeine or, if you'd rather skip stimulants altogether, our pre-workouts without caffeine.

How to Take Pre-Workout

Every pre-workout has its own suggested use on the label, so always start there. In general, this is how to get the most out of it:

1. Check the serving. For Perfection Pre-Workout, one full serving is 2 scoops (320mg of caffeine). For the Pre-Workout Double Shot, one serving is half a bottle (50ml, 80mg of caffeine).
2. New to pre-workout or to a formula? Start with half a serving. That way you can see how your body reacts to the caffeine before going all in.
3. Mix it with 250 to 500ml of water. Shake well until the powder has fully dissolved. Want to switch it up? Try this pre-workout smoothie.
4. Drink it 30 to 60 minutes before training. More on timing below.
5. Count your other caffeine. Coffee, tea, energy drinks and cola all add to your daily total.

Some people like to take their pre-workout on an empty stomach because they feel it more. If it makes you feel nauseous, have a light snack an hour or so before. How much you've eaten and how much caffeine you've already had both affect how your pre-workout hits, so a bit of trial and error is normal.

Should You Dry Scoop Pre-Workout? Why We Recommend Water

Dry scooping means swallowing a scoop of pre-workout powder straight from the tub, without water. It's a trend you've probably seen on social media, often sold as a way to make pre-workout kick in faster. We don't recommend it, and here's why:

• Choking and inhaling powder. Fine, dry powder can easily go down the wrong way, which can cause coughing fits or worse.
• All the caffeine at once. A full dose hits your system in one go, which makes side effects like a racing heart or nausea more likely.
• No proven benefit. There's no evidence that dry scooping works better than mixing with water.

Pre-workouts are made to be mixed with water, and that's how they work best. Want it to feel a bit quicker? Use less water, for example around 250ml, and drink it within a few minutes. And if you don't want to mix anything at all, a ready-to-drink Pre-Workout Double Shot is the safe, no-shaker alternative.

When Should You Take Pre-Workout?

The sweet spot for most people is 30 to 60 minutes before training. Caffeine usually reaches its peak level in your blood within that window, so you're at your sharpest just as you start your warm-up.

Training in the evening?

Caffeine taken within around six hours of bedtime can affect your sleep, and good sleep matters just as much for your progress as your training. If you train late, you have a few options: take your pre-workout earlier, use a smaller serving, or switch to a pre-workout without caffeine for your evening sessions.

How Long Does Pre-Workout Take to Kick In, and How Long Does It Last?

Most people feel the first effects of their pre-workout within 15 to 30 minutes, with caffeine peaking in the blood after 30 to 60 minutes. That's why we recommend taking it in that window before you train.

The effects of caffeine can last for several hours. On average, your body clears about half of it in around four hours, but that varies from two to eight hours depending on the person. So if you take your pre-workout at 6pm, a good part of that caffeine may still be in your system at bedtime. You can read more about this in our caffeine guide.

Why Does Pre-Workout Make You Itchy or Tingle?

That tingling or itchy feeling on your face, neck, ears or hands comes from beta-alanine. The technical term is paraesthesia, and it's completely harmless. It usually starts 10 to 20 minutes after taking your pre-workout and fades by itself within about an hour.

How strongly you feel it depends on the dose and on you: some people barely notice it, others find it intense the first few times. Many people notice it less the longer they use beta-alanine. Not a fan? Start with half a serving, or choose a formula with less beta-alanine.

Can You Take Pre-Workout Every Day?

You can, as long as you stick to the suggested use on the label and stay within 400mg of caffeine a day in total. That said, most people don't need it every day. On rest days there's simply no reason to take it.

Your body also gets used to caffeine over time, so the same dose can start to feel weaker. A few tips to keep your pre-workout working for you:

• Save it for your toughest sessions, like heavy leg day, rather than every workout.
• Take a break from caffeine every now and then, for example one or two weeks, to reset your sensitivity.
• Keep an eye on your sleep. If it's suffering, cut back or train earlier.

Is Pre-Workout Bad for You? Side Effects and Safety

For healthy adults, pre-workout is safe to use when you follow the suggested use. All our products comply with strict European regulations. According to the European Food Safety Authority (EFSA), healthy adults can safely consume up to 400mg of caffeine a day, and single doses of up to 200mg don't raise safety concerns, including when taken shortly before exercise. Those numbers are based on a 70kg adult, so your own limit depends on your body weight.

Some pre-workouts contain more than 200mg per full serving. Perfection Pre-Workout, for example, contains 320mg, so whether a full serving suits you depends on your body weight and on how used to caffeine you are (see the examples above). New to pre-workout? Start with 1 scoop, which is half a serving and 160mg of caffeine. Stimulants such as DMAA and DMHA, which you sometimes see in "hardcore" boosters online, are not permitted in food supplements in the UK and EU, and you won't find them in our products.

Possible side effects of pre-workout

Most side effects come from taking too much caffeine, or taking it too late in the day:

• restlessness, jitters or a racing heart
• nausea or an upset stomach
• trouble falling asleep
• a harmless tingling feeling from beta-alanine

Notice any of these? Lower your serving, take it earlier or cut back on other caffeine sources.

Who should avoid pre-workout?

Pre-workout isn't suitable for children and teenagers, and we recommend speaking to your doctor first if you:

• are pregnant or breastfeeding (EFSA advises a maximum of 200mg of caffeine a day)
• have a heart condition or high blood pressure
• take medication or have a medical condition
• are sensitive to caffeine

Pre-Workout vs Coffee: What's the Difference?

Both give you caffeine, but a pre-workout gives you an exact dose plus ingredients made for training. Here's the short version:

Want the full comparison, including energy drinks? Read pre-workout vs coffee vs energy drink.

Pre-Workout vs Creatine: What's the Difference?

Pre-workout and creatine are often mentioned in the same breath, but they work in completely different ways. A pre-workout is about the session in front of you: you take it before training and feel it within the hour. Creatine works by building up in your muscles over time, which is why the key is taking 3g every day, including rest days. The exact timing matters much less.

You can combine the two without any problem. Some pre-workouts, like JACK3D Advanced Pre-Workout, already contain creatine, but usually less than 3g. If you want the full amount, simply add a separate serving of creatine to your daily routine. Find out more in creatine vs pre-workout.

What Is the Best Pre-Workout for You?

The best pre-workout is the one that fits your training, your caffeine tolerance and the time of day you train. Ask yourself these questions:

• How used to caffeine are you? First time, or sensitive to caffeine? Start with half a serving, whichever pre-workout you choose.
• When do you train? For late sessions, a caffeine-free formula keeps your sleep safe.
• What are you after? A complete formula for pump, stimulation and focus, or something quick and convenient?
• Powder or ready-to-drink? Powder lets you adjust your dose scoop by scoop, a shot needs no shaker at all.

Our pre-workouts are suitable for both men and women. There's no need for a separate "women's pre-workout". What does matter is body weight, since the effect of ingredients like caffeine partly depends on it.

• Perfection Pre-Workout: our most fully loaded formula, with 15 active ingredients including 9,000mg of L-citrulline and 4,000mg of beta-alanine, 320mg of caffeine plus 198mg of theobromine, and our exclusive Brainberry® alongside L-tyrosine and choline. One serving is 2 scoops. Available in Fruit Punch, White Energy, Red Energy and Cherry. Everything about the formula is in our Perfection Pre-Workout blog.
• Pre-Workout Double Shot: the key ingredients of Perfection Pre-Workout in a ready-to-drink 100ml bottle: 160mg of caffeine, 4,000mg of L-citrulline, 2,000mg of beta-alanine and 65mg of Brainberry®, sugar-free. Each bottle holds two 50ml servings with 80mg of caffeine each, which is why it's called a double shot. No shaker, no scooping.
• JACK3D Advanced Pre-Workout: the comeback of a classic, with 130mg of caffeine per scoop plus L-citrulline, beta-alanine, creatine, L-tyrosine, Zynamite™ and VitaCholine™. Start with 1 scoop and build up to a maximum of 3 a day.
• Pre-workouts with caffeine and pre-workouts without caffeine: browse the full range by stimulant content.

What to Take Before and After a Workout

A pre-workout is one part of your routine, not the whole thing. What you do around your session matters just as much.

• Before: have a meal with carbohydrates and some protein around one to two hours before training, then take your pre-workout 30 to 60 minutes before you start.
• During: keep sipping water, especially during long or sweaty sessions.
• After: refuel with a protein-rich meal or shake. Protein contributes to the growth and maintenance of muscle mass, so a whey protein shake after training is an easy way to get your recovery started.

Hard work, consistency and good nutrition will always do the heavy lifting. The right pre-workout simply helps you make the most of every session, from the gym floor to the football pitch and beyond.

FAQ: Pre-Workout

What is the best pre-workout for beginners?

Start with half a serving: 1 scoop of Perfection Pre-Workout (160mg of caffeine) or half a bottle of the Pre-Workout Double Shot (80mg). That way you get to know how your body reacts before moving up to a full serving.

Does pre-workout without caffeine work?

Yes, but it works differently. Without caffeine you won't get the same "switched on" feeling, but ingredients like citrulline and beta-alanine still do their job. That makes a caffeine-free pre-workout a smart choice for evening sessions or if you're sensitive to caffeine.

Does pre-workout have calories?

Most pre-workouts contain very few calories per serving, since they're mainly made up of active ingredients and sweeteners. Check the nutritional information on the label for the exact amount.

Will pre-workout make me gain weight?

No. Pre-workout contains hardly any calories, so it won't cause fat gain. Formulas with creatine can cause some water retention, but that water is stored in your muscles, which may even give them a fuller look. Prefer to skip creatine? Perfection Pre-Workout and the Pre-Workout Double Shot contain none.

Is pre-workout good for weight loss?

A pre-workout doesn't burn fat on its own. Weight loss comes down to your overall diet and energy balance. What a pre-workout can do is help you feel alert and focused, so you can give your all in every session.

Does caffeine in pre-workout dehydrate you?

Caffeine stimulates your kidneys, but that doesn't mean it dehydrates you. You don't lose more water overall, you just go to the bathroom a little sooner. And since you mix your pre-workout with 250 to 500ml of water, you're already helping yourself stay hydrated.

Will I become dependent on pre-workout?

When people talk about a "strong" pre-workout, they usually mean its caffeine content. Your body gets used to caffeine over time, so the effect can feel weaker. This is nothing to worry about, but we don't encourage going above 400mg of caffeine a day. Cutting back for a while helps reset your sensitivity.

Pre-workout powder, capsules or shots: which works best?

Powder lets you adjust your serving easily and contains ingredients in doses that simply won't fit in a few capsules, like 9,000mg of citrulline in Perfection Pre-Workout. A Pre-Workout Double Shot is the handiest option on the go, since there's nothing to mix. Capsules are convenient too, but usually contain mostly caffeine.

How long does a tub of pre-workout last?

That depends on the number of servings in your tub and how often you train. A tub with 30 servings used four times a week lasts around seven to eight weeks. Check the servings on your label so you can restock before you run out.

Got more questions about pre-workout? Follow us on Instagram or check out our Nutrition Advice, Recipes and Workouts blogs for more tips.

Sources

• European Food Safety Authority (EFSA) - Scientific Opinion on the safety of caffeine
• European Commission - EU Register of nutrition and health claims
• International Society of Sports Nutrition - Position stand: caffeine and exercise performance
• International Society of Sports Nutrition - Position stand: beta-alanine
• Journal of Clinical Sleep Medicine - Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed
• National Institutes of Health (NIH) - Magnesium Fact Sheet
• NHS - Eat Well