Most people have no idea how much caffeine is actually in their pre-workout, only that it "hits hard" or it doesn't. Here's the real numbers, what's actually a safe amount, and how to choose between a stim and a stim-free option.
Jump to:
- How much caffeine is actually safe?
- STIM vs PUMP: caffeine and no caffeine
- Timing and how long it lasts
- Who should choose which
- Common myths
- Caffeine FAQs
How Much Caffeine Is Actually Safe?
Sports nutrition research generally supports doses of 3-6mg per kg of bodyweight for a performance benefit, which for most adults lands somewhere between 200-400mg. Regulatory bodies typically treat up to around 400mg per day as safe for healthy adults, though individual tolerance varies enormously.1
STIM vs PUMP: Caffeine and No Caffeine
Beast STIM contains 300mg of caffeine anhydrous per serving, carrying a high-caffeine-content warning on the label. That's a meaningful dose, in the upper part of the effective range, built for people who want energy and focus alongside performance support. Beast PUMP contains zero caffeine, built entirely around 8g of L-Citrulline for blood flow and pump, no stimulant at all.
Timing and How Long It Lasts
Caffeine typically starts having an effect within 30-45 minutes and has a half-life of roughly 5 hours in most people, meaning half of it is still in your system that long after you take it. That's why late sessions with a high-stim product can genuinely disrupt sleep hours later, worth factoring in if you train in the evening.
Who Should Choose Which
- Morning or early afternoon training, want energy and focus: STIM's 300mg dose is built for this.
- Evening training, sensitive to caffeine, or already taking other caffeinated products that day: PUMP removes the stimulant risk entirely without sacrificing the pump.
- Already getting caffeine from coffee or other sources pre-training: Factor STIM's 300mg on top of whatever else you've had that day against the ~400mg daily guidance.
Common Myths
- "More caffeine always means a better workout." Past a certain point, extra caffeine adds jitters and anxiety without extra performance benefit. More isn't automatically better.
- "Stim-free pre-workouts don't do anything." The "pump" is driven by nitric oxide and blood flow, not caffeine, a well-dosed stim-free formula like PUMP delivers that side of things without needing a stimulant at all.
- "You build a permanent tolerance so it stops working." Tolerance does build with daily high-dose use, but it's reversible with a short break, not permanent.
Caffeine FAQs
Eddie's take: "I know exactly what I'm getting with STIM before a heavy session. On off days or evening sessions, PUMP does the job without keeping me up half the night."
Beast STIM and PUMP
STIM Pre-Workout
30 Servings£34.99
Performance. Precision. No compromises.
Beast Pharm STIM is a clinically-dosed pre-workout built around 6g Citrulline Malate 2:1, 3.2g Beta-Alanine, 300mg Caffeine Anhydrous, and a precision nootropic stack of Tyrosine, Juniper Berry, Sausage Tree Extract, and Juglans Whole Fruit Extract. Every ingredient at an efficacious dose. No proprietary blends. No pixie dusting. No guesswork.
Most pre-workouts give you the feeling of performance. STIM gives you the performance. There's a difference, and after one session, you'll know exactly what it is.
Developed and approved by Eddie Hall, World's Strongest Man.
†Citrulline Malate supports blood flow and oxygen delivery to working muscles. Beta-Alanine at 3.2g supports muscular endurance. Caffeine contributes to increased endurance performance and alertness.
Directions
Mix 1 scoop (13g) with 250ml to 350ml of water.
Consume approximately 20-30 minutes prior to workout.
Ingredients
Citrulline Malate 2:1, Beta Alanine, Tyrosine, Caffeine Anhydrous, Juniper Berry Extract, Sausage Tree Extract, Juglans Whole Fruit Extract (Walnut), Flavouring, Anti-caking agent (Aerosil®, Sipernat®), Maltodextrin, Sweetener (Sucralose).
NET WT. 390g. No artificial; colours.
Warnings
HIGH CAFFEINE CONTENT. Please consult your physician prior to use (especially if you have a medical condition). Not recommended for anyone under the age of 18. Do not take this product if you are pregnant or breast feeding. If you are taking any medication consult your doctor before taking this product. Do not exceed the suggested use. Keep out of the reach of children. This product is not intended to diagnose, treat, cure, or prevent any disease or illness. Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.
Note: Due to the hygroscopic (absorbs moisture from the air) nature of the active ingredients, and our commitment to never use unnecessary fillers or preservatives, a degree of clumping may be observed in this product. This is perfectly normal, not affecting its effectiveness in any way and will dissolve normally in water as designed. It is advised to keep the product in a dry environment away from humidity and heat. During hot periods, storing in colder temperatures such as a fridge will help to offset this.
Allergens
For allergens please see the ingredients listed in bold. Contains nuts. Manufactured in a facility that processes celery/celeriac, crustaceans, fish, milk, mustard, peanuts, soya, gluten, egg, lupin, molluscs, nuts, sesame and sulphur dioxide.
Delivery
All UK orders are shipped using a 1-2 working day service.
Free Tracked 24 shipping is available on all orders over £25, for orders under £25 shipping is charged at £4.99
Orders placed before 1pm on weekdays are shipped the same day.
Orders placed at weekends and bank holidays will be processed on the next working day.
Europe - Please allow 5 - 10 business days for delivery. Orders under 150 EUR - including shipping costs - will not incur any customs or VAT charges.
Rest of the World - Please allow 7 - 14 business days for delivery.
DHL EXPRESS WORLDWIDE - 1 - 3 business days.
All orders are shipped tracked - a tracking link will be provided in your shipping confirmation email.
Additional Charges
Customers may incur VAT charges and Customs Duty specific to their country. The buyer assumes responsibility for any importation costs. If customs and duty fees imposed by your country are not paid, we cannot accept responsibility for the items. It is essential to familiarize yourself with your country's regulations regarding the importation of goods. If an item is confiscated due to regulations, we are not liable, and any resulting charges will be the customer's responsibility. For information regarding return shipping costs, please refer to our Refund Policy.
PUMP Stimulant Free Pre-Workout
30 Servings£34.99
Maximum pump. Zero stimulants.
Beast Pharm PUMP is built around 8g of pure L-Citrulline per serving, the premium form of citrulline for maximum nitric oxide production and one of the highest doses in any pre-workout on the market.† Alongside Betaine Anhydrous, Taurine, Epicatechin, CellFlo6™, Pine Bark Extract, and AstraGin® for absorption.
No caffeine. No crash. No compromise on the pump.
Most stim-free pre-workouts are just underdosed citrulline and a prayer. PUMP is the real thing: built for evening training, stimulant-free days, or anyone who knows the pump is driven by blood flow, not caffeine.
Developed and approved by Eddie Hall, World's Strongest Man.
†L-Citrulline at 8g per serving supports nitric oxide production and blood flow to working muscles.
Directions
Mix 1 scoop (15g) with 250ml to 350ml ofwater.
Consume approximately 20-30 minutes prior to workout.
Do not consume more one serving in any 24 hour period.
Ingredients
L-Citrulline, Betaine Anhydrous, Taurine, Epicatechin, Green Tea Leaf Extract (Camellia sinesis) (as CellFlo6™), Pine Bark Extract, Astragalus membranaceus Extract (root) & Panax notoginseng Extract (root) (as AstraGin®), Flavouring, Citric Acid, Anti-caking agent (Aerosil®, Sipernat®), Sweetener (Sucralose).
NET WT. 450g. No artificial colours.
Warnings
Please consult your physician prior to use (especially if you have a medical condition). Not recommended for anyone under the age of 18. Do not take this product if you are pregnant or breast feeding. If you are taking any medication consult your doctor before taking this product. Do not exceed the suggested use. Keep out of the reach of children. This product is not intended to diagnose, treat, cure, or prevent any disease or illness. Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.
Allergens
Manufactured in a facility that processes celery/celeriac, crustaceans, fish, milk, mustard, peanuts, soya, gluten, egg, lupin, molluscs, nuts, sesame and sulphur dioxide.
Delivery
All UK orders are shipped using a 1-2 working day service.
Free Tracked 24 shipping is available on all orders over £25, for orders under £25 shipping is charged at £4.99
Orders placed before 1pm on weekdays are shipped the same day.
Orders placed at weekends and bank holidays will be processed on the next working day.
Europe - Please allow 5 - 10 business days for delivery. Orders under 150 EUR - including shipping costs - will not incur any customs or VAT charges.
Rest of the World - Please allow 7 - 14 business days for delivery.
DHL EXPRESS WORLDWIDE - 1 - 3 business days.
All orders are shipped tracked - a tracking link will be provided in your shipping confirmation email.
Additional Charges
Customers may incur VAT charges and Customs Duty specific to their country. The buyer assumes responsibility for any importation costs. If customs and duty fees imposed by your country are not paid, we cannot accept responsibility for the items. It is essential to familiarize yourself with your country's regulations regarding the importation of goods. If an item is confiscated due to regulations, we are not liable, and any resulting charges will be the customer's responsibility. For information regarding return shipping costs, please refer to our Refund Policy.
References
- Guest, N. S., VanDusseldorp, T. A., Nelson, M. T., Grgic, J., Schoenfeld, B. J., Jenkins, N. D. M., Arent, S. M., Antonio, J., Stout, J. R., Trexler, E. T., Smith-Ryan, A. E., Goldstein, E. R., Kalman, D. S., & 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. https://doi.org/10.1186/s12970-020-00383-4
This article is for informational purposes and is not medical advice. Consult a healthcare professional before starting any new supplement, particularly if you have an existing health condition, are pregnant or breastfeeding, are under 18, or are sensitive to stimulants.