How much caffeine does a pre-workout contain and how much do you need?

The evidence-backed dose is 3 to 6 mg per kilo of body weight, so between 210 and 420 mg for a 70 kg person. Many commercial pre-workouts are around 200-300 mg per serving. Count the day’s coffee too: the caffeine in the tub and in the cup is the same molecule.

Why does my face tingle after taking a pre-workout?

It is beta-alanine, and it is called paraesthesia. It is harmless, lasts about twenty minutes and does not mean the product is stronger or working: it appears with each serving, whereas the benefit of beta-alanine depends on taking it daily for weeks.

Can you take a pre-workout every day?

You can, but it loses its point. Caffeine tolerance develops within two or three weeks of daily use, and from then on you are paying to get back to normal rather than to improve. Saving it for hard sessions is cheaper and more effective.

Is a caffeine-free pre-workout any use?

It depends on what it contains and at what dose. Without caffeine you lose the active with the most evidence, leaving beta-alanine and citrulline, which need 4-6 g and 6-8 g respectively to be in a useful range. If the tub does not reach those figures, what is left is flavour.

Why do so many pre-workouts show up as underdosed?

Because they contain the ingredient but not the dose that was studied. Putting a name on the label is cheap; putting six grams of that ingredient in every serving is expensive. This site compares the declared milligrams with the cited reference dose, and when they fall short it says so.

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Pre-workouts · Moderate evidence

What a pre-workout does and which ingredients actually work

The short answer. In a pre-workout, what almost always works is the caffeine. The other actives have known, published effective doses, and many tubs do not reach them: they fill the label with names at token doses. That is why this site flags underdosed products instead of trusting the ingredient list, and why a tub with a proprietary blend cannot be compared with anything.

There are studies in favour, but few, with small samples or measuring markers instead of outcomes. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of pre-workout with their source
Effect	How much	Detail
Caffeine: muscular strength and endurance	consistent effect	An umbrella review of 21 meta-analyses finds an effect on muscular endurance, strength, anaerobic power and aerobic endurance. It is the active that almost everything you notice depends on. [1][2]
Caffeine: perceived effort	lowers it	The same work feels less hard. Part of the performance gain comes from there, not from producing more power. [2]
Beta-alanine: efforts of 1 to 4 minutes	+2.85 %	Median of a meta-analysis, and only in that duration range: it does nothing for a set of five reps. It also depends on the dose accumulated over weeks, not today’s serving. [3][4]
Citrulline malate	6 to 8 g per serving	That is the range used in the performance studies, with mixed results. Many pre-workouts carry 1 or 2 g: below any dose that has been studied. [5]

02 How to take it

Dose. Caffeine: 3 to 6 mg per kilo of body weight. For 70 kg, between 210 and 420 mg. Beta-alanine: 4 to 6 g a day.
When. 30 to 60 minutes before. Caffeine peaks in the blood at around 45 minutes.
How long before you notice it. Caffeine, on day one. Beta-alanine needs 2 to 4 weeks of daily servings.

Details that change the result

Caffeine has a half-life of 5 to 6 hours. A pre-workout at 7 pm leaves half the dose in your body at midnight, and sleeping worse wipes out the gain you paid for.
The tingling in the face and hands is beta-alanine (paraesthesia). It is harmless and does not measure how strong the product is.
Caffeine tolerance builds within 2 or 3 weeks of daily use. Saving it for hard sessions keeps the effect.
Proprietary blend means you cannot know the dose of anything. A tub that does not publish the milligrams of each active cannot be compared, and on this site that costs it in the score.

03 When it makes sense and when it does not

Worth it if

A demanding session with short rests, or training early in the morning.
Competition or a strength test day.
Occasional days of poor rest when you still need to get the session done.

Not worth it if

Afternoon or evening sessions if your sleep is tight. The cost in sleep is higher than the gain.
Every day out of habit: tolerance turns it into spending with no effect.
High blood pressure, arrhythmias, anxiety or pregnancy: that is a question for a doctor, not a price table.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

Guest NS et al. ISSN position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18:1. 3-6 mg/kg de peso corporal. doi:10.1186/s12970-020-00383-4
Grgic J et al. Wake up and smell the coffee: caffeine supplementation and exercise performance. An umbrella review of 21 published meta-analyses. Br J Sports Med. 2020;54(11):681-688. doi:10.1136/bjsports-2018-100278
Hobson RM et al. Effects of beta-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012;43(1):25-37. Mejora mediana del 2,85 % en esfuerzos de 60 a 240 segundos. doi:10.1007/s00726-011-1200-z
Trexler ET et al. ISSN position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015;12:30. 4-6 g diarios durante al menos 2-4 semanas. doi:10.1186/s12970-015-0090-y
Kerksick CM et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15:38. doi:10.1186/s12970-018-0242-y

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about pre-workout

Answered with the data on this page

How much caffeine does a pre-workout contain and how much do you need?: The evidence-backed dose is 3 to 6 mg per kilo of body weight, so between 210 and 420 mg for a 70 kg person. Many commercial pre-workouts are around 200-300 mg per serving. Count the day’s coffee too: the caffeine in the tub and in the cup is the same molecule.
Why does my face tingle after taking a pre-workout?: It is beta-alanine, and it is called paraesthesia. It is harmless, lasts about twenty minutes and does not mean the product is stronger or working: it appears with each serving, whereas the benefit of beta-alanine depends on taking it daily for weeks.
Can you take a pre-workout every day?: You can, but it loses its point. Caffeine tolerance develops within two or three weeks of daily use, and from then on you are paying to get back to normal rather than to improve. Saving it for hard sessions is cheaper and more effective.
Is a caffeine-free pre-workout any use?: It depends on what it contains and at what dose. Without caffeine you lose the active with the most evidence, leaving beta-alanine and citrulline, which need 4-6 g and 6-8 g respectively to be in a useful range. If the tub does not reach those figures, what is left is flavour.
Why do so many pre-workouts show up as underdosed?: Because they contain the ingredient but not the dose that was studied. Putting a name on the label is cheap; putting six grams of that ingredient in every serving is expensive. This site compares the declared milligrams with the cited reference dose, and when they fall short it says so.

And now, which to buy

Prices, kept apart from the evidence

This page explains what pre-workout does and deliberately names no brand. The comparison is the other half: 124 products from 13 stores from €21.99 per kg, sorted by price and by how verifiable their certification is.

See the pre-workouts comparison

Other guides

What each supplement does, with its sources