Short answer: Picking a pre-workout starts with one number: caffeine. The ISSN's review describes caffeine doses of 3–6 mg per kg of body weight in research, and the FDA cites 400 mg a day as an amount not generally linked to negative effects for most adults. Count every source you have that day, not just the scoop.
Okay, real talk. You had a latte at 8, a "tiny" iced coffee at noon, and a scoop of pre-workout at 5:30, and now you're vibrating next to the squat rack wondering what happened. Nothing mysterious happened. Nobody added it up.
So we're starting a new habit: the caffeine receipt. Every coffee, tea, soda and scoop is a line item, and the total is what counts. The barista won't print you one, so we will. First, let's look at what's actually in the tub.
What's usually in pre-workout?
Most pre-workouts are a flavored powder you mix with water. The ingredient list changes from brand to brand, but a few names show up again and again:
- Caffeine. The headline ingredient, and the one this guide is about. It's listed in milligrams (mg) per serving.
- Beta-alanine. An amino acid that is the usual reason for the tingly feeling some people get (more on that below).
- Other ingredients, such as citrulline malate or L-theanine. Check the label for the amount of each.
- Sweeteners and flavors. These decide whether you'll actually enjoy drinking it.
If a label doesn't tell you how much caffeine is in a serving, that's your first red flag. Everything else in this guide depends on that number.
How much caffeine is a lot?
There's no one answer, because people react to caffeine very differently. The FDA notes that sensitivity to caffeine varies widely from person to person (FDA, "Spilling the Beans," 2024). What you can do is put your number in context.
Caffeine by body weight
The International Society of Sports Nutrition (ISSN) position stand on caffeine describes doses of 3–6 mg per kg of body weight in exercise research, with some studies showing effects at doses as low as 2 mg/kg. It also notes that very high doses, around 9 mg/kg, came with a high rate of side effects (Guest et al., 2021). These are amounts studied in research, not a personal recommendation.
Here's what those research amounts look like at different body weights. The math: body weight in pounds ÷ 2.2046 = kg, then kg × mg/kg = mg of caffeine. Numbers are rounded to the nearest milligram.
| Body weight | In kg (lb ÷ 2.2046) | 2 mg/kg | 3 mg/kg | 6 mg/kg | FDA daily reference |
|---|---|---|---|---|---|
| 110 lb | 49.9 kg | 100 mg | 150 mg | 299 mg | 400 mg/day |
| 130 lb | 59.0 kg | 118 mg | 177 mg | 354 mg | 400 mg/day |
| 150 lb | 68.0 kg | 136 mg | 204 mg | 408 mg† | 400 mg/day |
| 170 lb | 77.1 kg | 154 mg | 231 mg | 463 mg† | 400 mg/day |
| 190 lb | 86.2 kg | 172 mg | 259 mg | 517 mg† | 400 mg/day |
| 210 lb | 95.3 kg | 191 mg | 286 mg | 572 mg† | 400 mg/day |
† More than the FDA's 400 mg a day for most adults, in a single serving and before any coffee, tea or soda. The FDA's figure is for healthy adults. If you're pregnant, trying to get pregnant or breastfeeding, sensitive to caffeine, take medication, have a heart condition or high blood pressure, or are under 18, the 400 mg figure isn't your number. Talk with your healthcare provider first.
One more thing to keep in mind: the research doses are single doses, while the FDA's 400 mg is for your whole day. A smaller number is a perfectly good place to be.
The FDA's 400 mg a day reference
For most adults, the FDA has cited 400 mg of caffeine a day, about two to three 12-oz cups of coffee, as an amount not generally associated with negative effects. It adds that people vary widely in how sensitive they are to caffeine. It also points out that people who are pregnant, trying to get pregnant or breastfeeding should talk with their healthcare provider about caffeine (FDA, "Spilling the Beans," 2024).
Counting all your caffeine
Time to print the receipt. Here are typical amounts the FDA lists for 12-oz drinks (FDA, "Spilling the Beans," 2024):
| Line item (12 oz) | Caffeine |
|---|---|
| Brewed coffee | 113–247 mg |
| Energy drink | 41–246 mg |
| Black tea | 71 mg |
| Soft drink | 23–83 mg |
| Green tea | 37 mg |
Decaf isn't zero, either. The FDA lists 2–15 mg per 8-oz cup. The FDA also says there's no difference in how your body handles caffeine that occurs naturally, like in coffee and tea, and caffeine that's added to a product, so all of it goes on the receipt (FDA, "Spilling the Beans," 2024).
Sample receipt (made-up day): one 12-oz coffee (113–247 mg) + one 12-oz black tea (71 mg) + one 12-oz soda (23–83 mg) = 207–401 mg before a single scoop of pre-workout. Add the caffeine per serving from your pre-workout label, and that's your real total.
The FDA lists signs of too much caffeine: increased heart rate, heart palpitations, high blood pressure, insomnia or sleep disruptions, anxiety, jitters, upset stomach, nausea and headache. It also estimates that toxic effects, like seizures, can show up with rapid intake of around 1,200 mg (FDA, "Spilling the Beans," 2024). If you notice any of those signs, the FDA recommends talking with your healthcare professional.
Starting with less than a full serving
Some pre-workout labels tell you to try a partial serving first to see how you react. If your label says that, follow it. If it doesn't, stick to the label's directions and ask your doctor before changing the amount.
Reading a pre-workout label
A pre-workout label is basically a receipt you get before you buy. Here's how to read it.
Proprietary blends
Under FDA rules, a supplement can group ingredients into a "proprietary blend." The label then lists only the blend's total weight, with the ingredients in descending order by weight, and doesn't show how much of each one is in there (21 CFR 101.36(c)). If caffeine sits inside a blend, look for a separate line that states its milligrams. If you can't find one, you can't add it to your receipt.
Caffeine per serving
Find caffeine on the Supplement Facts panel, in mg per serving. Then check the serving size, too. If one serving is two scoops, a single scoop is half the caffeine, and a double scoop is double.
Beta-alanine tingles: what it is
That pins-and-needles feeling on your face, neck or hands has a name: paraesthesia. The ISSN's position stand on beta-alanine says it's the only side effect reported in the research, and that it can be lessened by taking smaller divided doses (for example, 1.6 g) or a sustained-release form (Trexler et al., 2015). If the tingle bothers you, check how much beta-alanine is in a serving and talk to your doctor.
When to take pre-workout
Start with the directions on your label. For reference, the ISSN notes that caffeine is commonly taken about 60 minutes before exercise in research, and that the best timing may depend on the form of caffeine (Guest et al., 2021).
Bedtime matters too. In a sleep study, 400 mg of caffeine taken at bedtime, three hours before bed or six hours before bed all disrupted sleep. The authors suggested skipping caffeine for at least six hours before bed (Drake et al., 2013). If you train after work, that might mean an earlier workout, a smaller amount or a caffeine-free day.
Who should skip caffeine or ask a doctor first
Talk to your doctor before using any caffeinated pre-workout if:
- You're pregnant, trying to get pregnant or breastfeeding (the FDA recommends talking with your healthcare provider).
- You have a heart condition or high blood pressure.
- You take any medication. The FDA notes some medications and conditions can make people more sensitive to caffeine.
- You're sensitive to caffeine, or caffeine has made you feel jittery or anxious before.
- You're under 18.
- You have any other medical condition.
Wellah Pre-Workout: what's on the label
Flavor first, because that's what you'll taste every day. See the Wellah Pre-Workout product page for current flavors and price. It's a flavored drink mix, so it sips more like a juicy summer drink than a chalky shake.
Here's what each serving lists, line by line, from the Wellah Pre-Workout label:
- Caffeine: 200 mg per serving. On our product page we say it plainly: count it with any coffee or energy drinks you have that day. Add it to your receipt.
- Citrulline malate: 5 g per serving.
- Beta-alanine: 1,000 mg per serving.
- Label warning: "Do not consume more than 400 mg of caffeine from any source in a 24 hour period."
- Directions: mix 1 scoop daily with 6–10 oz of water, or as directed by your healthcare professional.
- Servings: 30 per tub.
We know a lot of supplements look cute and are priced like luxury items. As our founder, Lizzy Pinckney, puts it, "Buying supplements shouldn't be stressful or expensive." So check the price on the product page and work out the price per serving (price ÷ 30 servings), just like you add up the caffeine.
Powder or stick packs?
Same idea, different packaging. A tub means you scoop each serving at home. Pre-Workout Stick Packs are single servings you can throw in a gym bag. See the product page for current flavors and price. Check the caffeine per stick on the label for your flavor (the Raspberry Lemonade stick lists 200 mg). Compare the price per serving on each product page; the sticks travel better. Either way, the caffeine goes on the receipt.
Want creatine in the same scoop? Pre-Workout + Creatine combines both in one drink mix. Check its label for the caffeine per serving, just like any other pre-workout.
FAQ
Why does pre-workout make me tingle?
The tingle usually comes from beta-alanine. The ISSN says this pins-and-needles feeling, called paraesthesia, is the only side effect reported in beta-alanine research, and that smaller divided doses or sustained-release forms can lessen it. Check the beta-alanine amount on your label.
Can I take pre-workout every day?
Count your total caffeine for the day, not just the scoop. For most adults, the FDA cites 400 mg a day as an amount not generally linked to negative effects, and it notes that sensitivity varies a lot. Follow your label's directions, and ask your doctor if you're unsure.
Can I have pre-workout with coffee?
Add them up first. The FDA lists 113 to 247 mg of caffeine in a 12-oz brewed coffee, so coffee plus a pre-workout can add up quickly. Check the caffeine per serving on your pre-workout label and keep your daily total in view.
Is it okay to take pre-workout in the evening?
Caffeine can affect sleep for hours. In one study, 400 mg of caffeine taken even six hours before bed disrupted sleep, and the authors suggested avoiding caffeine for at least six hours before bedtime. An earlier workout or a caffeine-free option may suit evenings better.
Should I get powder or stick packs?
It depends on your routine. With a tub you scoop each serving at home, while stick packs are pre-measured single servings for travel or the gym bag. Compare the price per serving and the caffeine per serving on each label before you choose.
This article is for general information and is not medical advice. Talk to your doctor before starting any new supplement, especially if you are pregnant or nursing, have a health condition, or take medication.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Related guides
References
- Guest NS, VanDusseldorp TA, Nelson MT, et al. International Society of Sports Nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1. doi:10.1186/s12970-020-00383-4
- U.S. Food and Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much? Updated 08/28/2024. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
- Trexler ET, Smith-Ryan AE, Stout JR, et al. International Society of Sports Nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015;12:30. doi:10.1186/s12970-015-0090-y
- Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013;9(11):1195–1200. doi:10.5664/jcsm.3170
- Code of Federal Regulations, 21 CFR 101.36(c), Nutrition labeling of dietary supplements. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-101/subpart-C/section-101.36
