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Short answer: Most pre-workouts last about 4 to 6 hours, because MedlinePlus says that is how long you may feel the effects of caffeine. The caffeine peaks 30 to 120 minutes after you take it, and the tingling from beta-alanine usually fades within 60 to 90 minutes. Caffeine stays in your body much longer than you feel it: in a review of sleep studies, a typical serving needed at least 13.2 hours before bed to avoid losing sleep.
You take a scoop before the gym, feel the rush and the tingles, and a few hours later you are wondering why you are still wired at bedtime, or why you suddenly feel flat. A pre-workout is not one ingredient with one timeline. Caffeine, beta-alanine, citrulline and creatine each work on a different clock. Here is how long each one lasts, when the whole thing kicks in and wears off, and how late is too late to take it. If your pre-workout is a cup of coffee, see coffee before a workout.
What you'll learn
- When pre-workout kicks in and when it peaks
- How long each common ingredient lasts, from caffeine to creatine
- How long caffeine stays in your system after you stop feeling it
- Why pre-workout makes you tingle, and how long it lasts
- How long before bed to take it, and why you might crash
- Whether pre-workout expires after opening or mixing
How long does pre-workout last?
You will usually feel a pre-workout for about 4 to 6 hours, which is how long caffeine's effects can be felt (MedlinePlus). That is the main timeline, because 86% of top-selling pre-workouts list caffeine, at an average of 254 mg per serving (Jagim et al., 2019). The other common ingredients each run on their own schedule:
| Ingredient | Found in top sellers | When it peaks or starts | How long it lasts |
|---|---|---|---|
| Caffeine | 86%, average 254 mg (Jagim et al., 2019) | 30 to 120 minutes (Guest et al., 2021) | Felt 4 to 6 hours (MedlinePlus); half-life 4 to 6 hours on average (Guest et al., 2021) |
| Beta-alanine (the tingles) | 87%, average 2.0 g (Jagim et al., 2019) | Soon after you take it | Tingling usually gone within 60 to 90 minutes (Trexler et al., 2015) |
| Citrulline (the "pump") | 71%, average 4.0 g (Jagim et al., 2019) | Blood arginine peaked about 1 to 2.3 hours later (Moinard et al., 2008) | No study measured the pump itself |
| Creatine | 49%, average 2.1 g (Jagim et al., 2019) | No same-day boost; builds up over days to weeks (Kreider et al., 2017) | Muscle stores take 4 to 6 weeks to fall back after stopping (Kreider et al., 2017) |
Two things make your own timeline hard to predict. Products average more than 18 ingredients, and 44.3% of all ingredients are hidden in proprietary blends with no listed amounts (Jagim et al., 2019). And people clear caffeine at very different speeds, which we cover below.
How long does pre-workout take to kick in?
Most people start to feel it within about 30 to 60 minutes. Caffeine shows up in your blood within minutes, and blood levels peak somewhere between 30 and 120 minutes after you take it (Guest et al., 2021). That is why the most common timing in caffeine studies is 60 minutes before exercise (Guest et al., 2021).
A big meal can slow caffeine down; see how long caffeine takes to kick in for what studies measured with and without food.
How long does pre-workout stay in your system?
The caffeine stays much longer than you feel it, often most of a day. The average half-life of caffeine is generally reported as 4 to 6 hours, but it can range from 1.5 to 10 hours in adults (Guest et al., 2021). Your liver does the work: only about 3% to 5% leaves your body in urine as caffeine (Guest et al., 2021), so drinking extra water will not flush it out.
Here is what that means for an average 254 mg serving taken at 5 p.m. With a 5-hour half-life, the middle of the average range, about 127 mg would still be in your body at 10 p.m. and about 64 mg at 3 a.m., by our calculation. That is why a pre-workout can keep you up long after the buzz is gone. Pregnancy and hormonal birth control can slow caffeine clearance (Guest et al., 2021). For more on half-life, see how long caffeine stays in your system.
How long do pre-workout tingles last?
The tingles usually go away within 60 to 90 minutes (Trexler et al., 2015). They come from beta-alanine, and the tingling, called paresthesia, is the only side effect reported for it (Trexler et al., 2015). It is common when people take more than 800 mg at once in a regular, non-sustained-release form (Trexler et al., 2015), and the average pre-workout has 2.0 g per serving (Jagim et al., 2019). Most people feel it on the face, neck and backs of the hands (Trexler et al., 2015).
The itchy, prickly feeling is not a sign of harm: the ISSN found no evidence that it is harmful (Trexler et al., 2015). It is also not a sign the product is working. Beta-alanine's performance benefit comes from taking 4 to 6 g a day for at least 2 to 4 weeks, not from the tingle (Trexler et al., 2015). Studies found smaller split doses (1.6 g) or sustained-release forms cut down the tingling (Trexler et al., 2015). If the feeling bothers you, look for a product with less or no beta-alanine.
How long does the pump from pre-workout last?
No study we found measured how long the visible "pump" lasts, but the blood changes behind it peak within about 1 to 2 hours. Citrulline is the usual pump ingredient, found in 71% of top sellers (Jagim et al., 2019). Your body turns it into arginine, which it uses to make nitric oxide, a molecule that helps blood vessels relax (Schwedhelm et al., 2008).
In 8 healthy men who took 2 to 15 g of citrulline after fasting, blood arginine peaked about 1.2 to 2.3 hours later, depending on the dose (Moinard et al., 2008). Citrulline raised blood arginine more effectively than taking arginine itself (Schwedhelm et al., 2008).
Does the creatine in pre-workout work right away?
No. Creatine works by filling up your muscle stores over days to weeks, not within an hour. In research, muscle stores fill fastest with a loading phase of 5 g four times a day for 5 to 7 days, or more gradually with 3 g a day for 28 days (Kreider et al., 2017). Once stores are full, they take 4 to 6 weeks to return to normal after you stop (Kreider et al., 2017).
Top-selling pre-workouts average 2.1 g of creatine per serving (Jagim et al., 2019), less than the 3 to 5 g a day usually recommended (Antonio et al., 2021), and you may not take a pre-workout every day. If you want creatine, taking it on its own every day is simpler. See whether you can put creatine in coffee.
How long before bed should you take pre-workout?
Take a regular pre-workout at least 13.2 hours before bed, according to a 2023 review of sleep studies. The analysis of 24 studies found caffeine cut total sleep by 45 minutes on average, and to avoid that loss, a standard pre-workout serving (217.5 mg of caffeine) should be taken at least 13.2 hours before bedtime (Gardiner et al., 2023). For coffee, the same review suggested at least 8.8 hours (Gardiner et al., 2023).
For a 10 p.m. bedtime, 13.2 hours means taking it before about 8:45 a.m., by our calculation. That rules out a full-strength scoop for most after-work training sessions. Caffeine also cut deep sleep and made it take longer to fall asleep in the review (Gardiner et al., 2023). If you train in the evening, consider a caffeine-free ("stim-free") formula, a smaller amount of caffeine, or none at all. See coffee before a workout for more on evening sessions.
Why do you crash after pre-workout?
The "crash" is usually the tiredness that caffeine was covering up, coming back as the caffeine fades. Your body builds up adenosine, a chemical that promotes sleep, and caffeine works mainly by blocking it (Guest et al., 2021). When the caffeine level drops, you feel that sleep pressure again. There is little research on the pre-workout crash itself, so how long it lasts varies from person to person.
What tends to help:
- Take less. A smaller scoop gives the caffeine less to wear off from.
- Do not stack it. Skip the extra coffee or energy drink on pre-workout days.
- Eat and sleep. Caffeine does not replace fuel or rest. See what to eat after a workout.
For more, see how to avoid a caffeine crash and why caffeine can leave you tired.
How much caffeine is in pre-workout, and is it too much?
The average top-selling pre-workout has about 254 mg of caffeine per serving (Jagim et al., 2019), and that is already a big share of a day's limit. The FDA says 400 mg a day, about two to three 12-ounce cups of coffee, is not generally linked to negative effects in healthy adults (FDA). One average serving is about 64% of that, by our calculation, before any coffee, tea or energy drinks.
Check the label. Some products list caffeine only inside a proprietary blend (Jagim et al., 2019), and the FDA advises care the first time you use a new product if its caffeine amount is not declared (FDA). Rapidly taking in around 1,200 mg can cause toxic effects like seizures (FDA). See how much caffeine is too much and how much caffeine is in energy drinks.
Does pre-workout expire?
Use the powder by the date on the tub, and drink it soon after mixing. We found no study on how pre-workout powders change after their date, and the FDA does not approve dietary supplements before they are sold (FDA), so the date and storage directions on the label are your best guide. Keep the lid closed so the powder stays dry.
Mixing it with water is a different story, at least for creatine. Creatine monohydrate powder is very stable for years, but creatine is not stable in liquid, especially when it is warmer or more acidic (Antonio et al., 2021). Mixing a pre-workout right before you drink it, rather than the night before, avoids the question.
Who should be careful with pre-workout, and when should you get help?
Check with a provider first if you have certain health conditions, and get help right away if you have signs of too much caffeine. Talk to your provider before using a caffeinated pre-workout if you are pregnant, have high blood pressure, migraines, anxiety, GERD, ulcers, a heart rhythm problem or trouble sleeping, or take medicines that may interact with caffeine (MedlinePlus).
Get help right away for signs of too much caffeine, such as trouble breathing, confusion, a rapid or irregular heartbeat, vomiting or seizures (MedlinePlus). Call 911, or call Poison Help at 1-800-222-1222 (MedlinePlus).
Common myths (quick reality check)
Myth: The tingling means the pre-workout is working. Reality: Tingling is a side effect of beta-alanine. Its performance benefit comes from 4 to 6 g a day for at least 2 to 4 weeks (Trexler et al., 2015).
Myth: Once you stop feeling it, the caffeine is gone. Reality: You may feel caffeine for 4 to 6 hours (MedlinePlus), but its half-life averages 4 to 6 hours and can reach 10 (Guest et al., 2021), so much of it is still in your body.
Myth: Drinking lots of water flushes pre-workout out faster. Reality: Your liver clears caffeine; only about 3% to 5% leaves in urine unchanged (Guest et al., 2021).
Frequently asked questions (FAQ)
How long does pre-workout last?
Most people feel it for about 4 to 6 hours, mainly from the caffeine. The tingling from beta-alanine usually fades within 60 to 90 minutes.
How long does pre-workout take to kick in?
A sports nutrition review reports that caffeine peaks in the blood 30 to 120 minutes after you take it, so most people feel it within about 30 to 60 minutes. Studies most often use it 60 minutes before exercise.
How long does pre-workout last in your system?
Much longer than you feel it. According to a sports nutrition review, caffeine's average half-life is 4 to 6 hours, and it can range from 1.5 to 10 hours in adults.
How long does pre-workout tingle last?
Usually 60 to 90 minutes. The tingling comes from beta-alanine and has not been shown to be harmful.
How long before bed should I stop taking pre-workout?
A 2023 review of sleep studies suggests taking a standard pre-workout serving at least 13.2 hours before bed to avoid losing sleep.
How long does a pre-workout crash last?
It varies, and there is little research on it. The crash usually happens as caffeine wears off, which for most people is within about 4 to 6 hours of taking it.
Does pre-workout expire?
Use it by the date on the label and keep it dry. Once mixed with water, drink it soon, since creatine breaks down in liquid.
Can I drink coffee after taking pre-workout?
Be careful. An average serving has about 254 mg of caffeine, and the FDA's 400 mg daily amount is about two to three 12-ounce cups of coffee in total.
Related guides
- Coffee before a workout
- How long does caffeine stay in your system?
- How long does it take for caffeine to kick in?
- How much caffeine is too much?
- Can you put creatine in coffee?
- How much caffeine is in energy drinks?
- How to avoid a caffeine crash
- What to eat after a workout
Disclaimer and when to seek help
This article is for general education and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. Children and teens should have less caffeine than adults. If you are pregnant or breastfeeding, have a heart condition or high blood pressure, or take prescription medicines, ask your provider before using a caffeinated pre-workout.
References
- Jagim AR, Harty PS, Camic CL. "Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements." Nutrients, 2019;11(2):254. PMC6413194
- Guest NS, et al. "International society of sports nutrition position stand: caffeine and exercise performance." Journal of the International Society of Sports Nutrition, 2021;18(1):1. PMC7777221
- Trexler ET, et al. "International society of sports nutrition position stand: Beta-Alanine." Journal of the International Society of Sports Nutrition, 2015;12:30. PMC4501114
- Moinard C, et al. "Dose-ranging effects of citrulline administration on plasma amino acids and hormonal patterns in healthy subjects: the Citrudose pharmacokinetic study." British Journal of Nutrition, 2008;99(4):855-862. doi:10.1017/S0007114507841110
- Schwedhelm E, et al. "Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism." British Journal of Clinical Pharmacology, 2008;65(1):51-59. PMC2291275
- Kreider RB, et al. "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, 2017;14:18. PMC5469049
- Antonio J, et al. "Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?" Journal of the International Society of Sports Nutrition, 2021;18(1):13. PMC7871530
- Gardiner C, et al. "The effect of caffeine on subsequent sleep: A systematic review and meta-analysis." Sleep Medicine Reviews, 2023;69:101764. doi:10.1016/j.smrv.2023.101764
- MedlinePlus. "Caffeine"
- MedlinePlus. "Caffeine overdose"
- U.S. Food and Drug Administration. "Spilling the Beans: How Much Caffeine is Too Much?"
- U.S. Food and Drug Administration. "Questions and Answers on Dietary Supplements"
