Pre-workout is a supplement you take before training, usually a powder mixed with water, that combines ingredients such as caffeine, creatine, beta-alanine and L-citrulline in one drink. Most people use it to feel more alert and focused and to get more out of a session, especially when they're training early, late or straight after a long day.
The best time to take it is 20-60 minutes before you train. If you're new to it, start with half a serving to see how you react to the caffeine. This guide covers what pre-workout does, what's inside it, how much to take, the side effects to know about and how to choose the right one for you.
Jump to:
- What is pre-workout?
- Pre-workout ingredients
- When to take pre-workout
- Side effects
- Myprotein pre-workouts
- Frequently asked questions
What is pre-workout?
Pre-workout is a supplement formula designed to be taken before exercise. Most come as a flavoured powder that you mix with water, but you'll also find gels, shots, gummies and dry scoop formulas. Instead of taking several supplements separately, a pre-workout combines popular performance ingredients in one serving.
Formulas vary a lot between products. Some are built around a big dose of caffeine, some leave caffeine out completely, and others add creatine, B vitamins or carbohydrates. That's why it pays to read the label before you choose one.
What does pre-workout do?
Pre-workout is designed to help you train harder by supporting alertness, focus and performance during your session. Most of the effect people notice comes from caffeine, while ingredients such as creatine and beta-alanine work over weeks of regular use.
A review of multi-ingredient pre-workouts found that taking one before exercise may improve muscular endurance and mood, with mixed results for strength and power.1 In one study, a caffeine-containing pre-workout improved power on a sprint cycling test compared with a placebo, but didn't improve strength.2 The same review noted that it's often hard to tell which ingredient is responsible, because many products use "proprietary blends" that don't list the amounts, and that long-term effects are less clear.1
Here's what the main ingredients are linked to:
- Caffeine: studied extensively in sport. Doses of around 3-6mg per kg of body weight, taken about an hour before exercise, have been shown to improve endurance, strength and power performance in many people.3
- Creatine: creatine increases physical performance in successive bursts of short-term, high-intensity exercise. The benefit comes from a daily intake of 3g, in adults doing high-intensity exercise.
- B vitamins: many formulas add vitamins such as B6, B12 and niacin, which contribute to the reduction of tiredness and fatigue.
A pre-workout won't replace a good diet, enough sleep or a well-planned programme. Think of it as a useful extra on the days you need it.
Pre-workout ingredients: what's in pre-workout?
Most pre-workouts are built from the same core ingredients, in different amounts. Here's what you'll see on the label and what the research says about each one.
Caffeine
Caffeine is the main active ingredient in most pre-workouts, usually at around 150-300mg per serving. Research shows caffeine can improve endurance performance and attention in most people.3
Creatine
Some pre-workouts include creatine, typically 3g per serving. Creatine increases physical performance in successive bursts of short-term, high-intensity exercise, with a daily intake of 3g, so it suits lifting, sprinting and interval training. It works by topping up your muscles' creatine stores over time, so it needs to be taken every day, not just before a session.4
Beta-alanine
Beta-alanine is the ingredient behind the tingling feeling some people get after taking a pre-workout. It's harmless and usually fades within 60-90 minutes. Research shows that a daily intake of 4-6g of beta-alanine for at least two to four weeks raises muscle carnosine levels and can improve performance, especially in efforts lasting one to four minutes.5
L-citrulline and citrulline malate
L-citrulline is an amino acid that features in most "pump" formulas. Supplementing with it raises blood levels of arginine and markers of nitric oxide, and several studies have reported better exercise performance, though evidence that it improves blood flow is scarce and inconsistent.6
B vitamins and vitamin C
Many formulas include B vitamins such as B6, B12 and niacin, and some add vitamin C. These contribute to the reduction of tiredness and fatigue when the product provides enough of them.
Other ingredients
You'll also often see taurine, L-tyrosine, L-theanine and arginine alpha-ketoglutarate (AKG). Impact Pre-Workout contains all four. Some products use branded ingredients, such as the Cognizin® citicoline in THE Pre-Workout. Some pre-workouts also contain carbohydrates, which can be useful before a long endurance session if you haven't eaten recently.
How to choose the right pre-workout for you
The best pre-workout for you depends on when you train, how sensitive you are to caffeine and the type of training you do. Start by checking three things on the label: the caffeine content, the main active ingredients and the serving size.
Stimulant or stimulant-free?
A stimulant pre-workout contains caffeine and suits morning or midday sessions. If you train in the evening, are sensitive to caffeine or already drink a lot of coffee, a stimulant-free (or "stim-free") pre-workout is a better choice. These keep ingredients like L-citrulline and beta-alanine but leave out the caffeine, so they won't keep you awake.
For example, if you finish work late and train at 8pm, a stim-free formula such as Origin Pump Pre-Workout lets you train hard and still get to sleep at a reasonable hour.
How strong should it be?
If you're new to pre-workout, choose a lower-caffeine formula such as Impact Pre-Workout (150mg of caffeine), or take half a serving of a stronger one. High-stim formulas with 300mg of caffeine per serving, like Origin Jacked, are designed for experienced users, not as an introduction.
What kind of training do you do?
For strength and high-intensity training, a formula that also includes 3g of creatine, such as THE Pre-Workout, saves you taking it separately. For longer endurance sessions, a lower-caffeine option like Pre-Workout Gummies (30mg of caffeine per gummy) alongside a carbohydrate snack may suit you better.
When to take pre-workout
Take your pre-workout 20-60 minutes before you start training, following the timing on the label. Our pre-workouts recommend 15-30 minutes beforehand, depending on the product, while studies on caffeine most often give it 60 minutes before exercise. Caffeine reaches the blood within minutes.3
How long does pre-workout take to kick in?
Caffeine is absorbed quickly, but it takes time to reach its peak: studies report peak blood levels anywhere from 30 to 120 minutes after you take it.3 If your formula contains beta-alanine, you may feel tingling soon after, which usually fades within 60-90 minutes.5 Some people find a pre-workout kicks in faster on an empty stomach.
How long does pre-workout last?
The energy boost usually lasts a few hours, but caffeine stays in your body for much longer. Caffeine's half-life (the time it takes your body to clear half of it) varies widely between people, from about 1.5 to 10 hours, with an average of 4-6 hours.3 That's why a stimulant pre-workout taken in the evening can affect your sleep.
How late can you take pre-workout?
Aim to take a stimulant pre-workout at least six hours before bed. In one study, 400mg of caffeine taken six hours before bedtime still significantly disrupted sleep, and the researchers recommend avoiding substantial caffeine for at least six hours before bed.8 If you train late, choose a stim-free formula such as Origin Jacked Pump.
What to eat and drink with pre-workout
Pre-workout isn't a replacement for food. If you have time, a light snack with carbs and some protein 60-90 minutes before training will give you energy to work with. A banana with nut butter, a bowl of oats or a protein shake all work well.
Mix your pre-workout with the amount of water the label recommends, and keep sipping water through your session.
How much pre-workout should you take?
Take the serving on the label and no more. If you're a beginner, start with half a serving to see how you react, then build up over a few sessions if you feel fine.
Because one scoop can contain very different amounts of caffeine depending on the product, it's worth checking how much you're getting. Count everything you have in a day, including coffee, tea, energy drinks and caffeine tablets. The European Food Safety Authority (EFSA) says that for healthy adults, single doses of up to 200mg and daily intakes of up to 400mg of caffeine don't raise safety concerns. For pregnant and breastfeeding women, EFSA's figure is up to 200mg a day.7
Pre-workouts aren't suitable for children or pregnant women. Speak to your GP before using one if you have a medical condition or take medication.
What are the side effects of pre-workout?
Most side effects of pre-workout come from caffeine and depend on the dose and how sensitive you are. A review concluded that multi-ingredient pre-workouts appear to be relatively safe, but most safety studies lasted less than eight weeks, so more research on long-term use is needed.1 The most commonly reported side effects of caffeine are a racing heart or palpitations, anxiety, headaches and poor sleep.3
Side effects to look out for include:
- Jitters, anxiety or a racing heart: usually a sign that the caffeine dose is too high for you. Try half a serving or a lower-caffeine product, such as Pre-Workout Gummies, where you choose how many to take.
- Poor sleep: caffeine late in the day can disrupt your sleep.8
- Tingling skin: caused by beta-alanine. It's harmless and wears off.5
- Stomach discomfort: caffeine can upset some people's stomachs,3 and some people find a pre-workout on an empty stomach doesn't agree with them. Have it with more water or after a small snack.
- Headaches when you stop: if you have caffeine every day, stopping suddenly can cause withdrawal symptoms such as headaches and tiredness, usually starting 12-24 hours later. This can happen even if you were only having 100mg a day.10
What about dehydration? Caffeine has a diuretic effect in large doses (500mg or more), but a study of regular coffee drinkers found that moderate intake hydrated them as well as water.9 Drinking water before and during training is still a good habit.
Myprotein pre-workout supplements
Whether you want a high-caffeine formula, a stim-free option or something you can take on the go, there's a pre-workout to suit how you train. Here are our options, with the details taken from each product page.
High-stim pre-workouts
Origin Jacked Pre-Workout is a high-stim pre-workout with 300mg of caffeine per serving to support alertness and concentration, plus 3g of creatine to help increase physical performance in successive bursts of short-term, high-intensity exercise. Each serving also has 5g of beta-alanine and 6g of L-citrulline.
Origin Pre-Workout combines 300mg of caffeine with 6g of active L-citrulline and 3.5g of beta-alanine. Caffeine helps increase endurance performance and capacity and helps improve concentration and increase alertness. It's a high-caffeine formula designed for experienced pre-workout users.
THE Pre-Workout has 200mg of caffeine, 250mg of Cognizin® citicoline and 3g of creatine monohydrate, plus vitamin B12, which contributes to the reduction of tiredness and fatigue.
A moderate-caffeine option
Impact Pre-Workout has 150mg of caffeine per serving, which increases endurance performance and capacity and improves concentration. It also contains taurine, beta-alanine and vitamins.
Stim-free pre-workouts
Origin Jacked Pump Pre-Workout is a stimulant-free formula built for pump-focused sessions, with 6g of L-citrulline and 5g of beta-alanine per serving. With no caffeine, it suits evening or late-night training.
Origin Pump Pre-Workout is caffeine-free, with 8g of L-citrulline DL-malate and 3.5g of beta-alanine per serving.
Pre-workouts for on the go
Origin Pre-Workout Dry Scoop is the UK's first approved dry scoop formula, with a "fast melt" ingredient designed to dissolve quickly and safely on your tongue. No water or mixing needed, and 147mg of caffeine per serving.
Pre-Workout Gummies contain 30mg of caffeine per gummy, so you can choose your dose, up to four gummies a day. They also contain niacin and vitamin B6.
THE Pre-Workout Gel can be taken straight from the sachet, with 200mg of caffeine per serving.
Please note: nutritional information may vary depending on flavour.
Frequently asked questions
Is pre-workout bad for you?
Pre-workout isn't bad for most healthy adults when taken as directed. The main thing to watch is caffeine: stick to the serving on the label and keep your total intake within 400mg a day from all sources.7
Should beginners take pre-workout?
Beginners can take pre-workout, but it isn't essential. Good food, sleep and a consistent programme matter more early on. If you do try one, start with half a serving of a lower-caffeine formula, such as Impact Pre-Workout.
Can you take pre-workout on an empty stomach?
Yes, and it may kick in faster, but some people find it causes stomach discomfort. If that's you, have a small snack first or take it with more water.
Can you dry scoop pre-workout?
Don't dry scoop a standard pre-workout powder. It's meant to be mixed with water, and swallowing dry powder can make you choke or breathe it in. Only dry scoop a product designed and approved for it, such as Origin Pre-Workout Dry Scoop.
Can you take pre-workout every day?
Most people only take pre-workout on training days. Creatine and beta-alanine work through regular daily intake, so on rest days you can take them on their own instead, for example Impact Creatine.4,5 Whatever you take, keep your total caffeine within 400mg a day.
Why is my pre-workout clumpy, and is it safe?
Clumping is normal. Ingredients like L-citrulline draw moisture from the air, so pre-workout can stick together, especially in humid places like a gym bag or a car. If the product is in date, it's still fine to use. To prevent clumps, close the lid tightly and store the tub in a cool, dry place.
Take home message
Pre-workout combines ingredients like caffeine, creatine and beta-alanine to help you feel alert and get more from your training. Take it 20-60 minutes before your session, start with half a serving if you're new to it, and keep your total caffeine within 400mg a day. Train in the evening? Choose a stim-free formula so it doesn't affect your sleep.
Browse our full pre-workout range to find the right one for you.
Founded in 2004, Myprotein has a long history of fuelling people’s fitness journeys. As the UK’s No. 1 Sports Nutrition Brand and Europe’s No. 1 Sports Nutrition Brand*, our mission is to provide you with reliable, evidence-based information, and our blog features articles from a trusted network of experts across fitness, nutrition and wellness. *Source Euromonitor International Limited; Consumer Health 2026 edition, retail value sales (RSP), all retail channels, 2025 data
References
- Harty, P. S., Zabriskie, H. A., Erickson, J. L., Molling, P. E., Kerksick, C. M., & Jagim, A. R. (2018). Multi-ingredient pre-workout supplements, safety implications, and performance outcomes: a brief review. Journal of the International Society of Sports Nutrition, 15(1), 41.
- Martinez, N., Campbell, B., Franek, M., Buchanan, L., & Colquhoun, R. (2016). The effect of acute pre-workout supplementation on power and strength performance. Journal of the International Society of Sports Nutrition, 13(1), 29.
- Guest, N. S., VanDusseldorp, T. A., Nelson, M. T., Grgic, J., Schoenfeld, B. J., Jenkins, N. D. M., … & Campbell, B. I. (2021). International Society of Sports Nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition, 18(1), 1.
- Kreider, R. B., Kalman, D. S., Antonio, J., Ziegenfuss, T. N., Wildman, R., Collins, R., … & Lopez, H. L. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14(1), 18.
- Trexler, E. T., Smith-Ryan, A. E., Stout, J. R., Hoffman, J. R., Wilborn, C. D., Sale, C., … & Antonio, J. (2015). International Society of Sports Nutrition position stand: beta-alanine. Journal of the International Society of Sports Nutrition, 12(1), 30.
- Gonzalez, A. M., & Trexler, E. T. (2020). Effects of citrulline supplementation on exercise performance in humans: a review of the current literature. Journal of Strength and Conditioning Research, 34(5), 1480-1495.
- EFSA Panel on Dietetic Products, Nutrition and Allergies (2015). Scientific opinion on the safety of caffeine. EFSA Journal, 13(5), 4102.
- Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine, 9(11), 1195-1200.
- Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One, 9(1), e84154.
- Juliano, L. M., & Griffiths, R. R. (2004). A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology, 176(1), 1-29.
