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Caffeine supplements, compared

12 products we’ve reviewed list caffeine as a key ingredient. Here’s what it does, what the research uses — and how much each product actually contains.

What it is

A stimulant that can improve endurance, strength and power and reduce how hard exercise feels.

What the research uses

Performance studies commonly use about 2–6 mg per kg of body weight before exercise — roughly 210–420 mg for a 70 kg (154 lb) adult. Taking more is unlikely to help further. The FDA cites 400 mg a day as an amount not generally associated with dangerous effects in healthy adults.

Count coffee, energy drinks and other supplements too. Avoid pure powdered caffeine, and talk to a doctor if you are pregnant, have a heart condition or anxiety, or take stimulant medication.

Educational information, not medical advice. Talk to a healthcare professional before starting a supplement, especially if you are pregnant, nursing or take medication.

Every product, dose by dose

ProductCaffeine per servingFormScore
BULK Pre-Workout
Transparent LabsBULK Pre-Workout
Informed Choice
200 mgPurCaf organic caffeinePowder8.5
Pulse Pre-Workout
LegionPulse Pre-Workout
Third-party testedcGMP facility
350 mgPowder8.3
Gorilla Mode Pre-Workout
Gorilla MindGorilla Mode Pre-Workout
Third-party tested
200 mg per scoopCaffeine anhydrousPowder8.2
Legend V4 Pre-Workout
GHOSTLegend V4 Pre-Workout		300 mgNatural caffeinePowder8.2
Pre-Kaged Pre-Workout
KagedPre-Kaged Pre-Workout
Informed Sport
274 mgPurCaf natural caffeinePowder8.1
Loaded Pre
RYSELoaded Pre		300–390 mg (varies by flavor)Caffeine (anhydrous + ZumXR extended-release)Powder7.9
Pre-Workout
Alani NuPre-Workout		200 mgCaffeine (from Coffea arabica bean extract)Powder7.5
Energy & Focus Gum
NeuroGumEnergy & Focus Gum		40 mg per pieceNatural caffeine (from green coffee beans)Chewable7.2
Essential AMIN.O. Energy
Optimum NutritionEssential AMIN.O. Energy
Informed Choice
100 mgCaffeine (from green tea and green coffee bean extracts)Powder7.0
C4 Original Pre-Workout
CellucorC4 Original Pre-Workout		200 mgCaffeine anhydrousPowder6.8
Original Mental Performance Shot
Magic MindOriginal Mental Performance Shot
Third-party tested
55 mgCaffeine (from organic matcha and green tea)Ready to drink5.4
Hardcore
HydroxycutHardcore		265 mg caffeine per servingCaffeine anhydrousCapsule4.6

Amounts are per serving as printed on each label. “Not disclosed” usually means the ingredient sits inside a proprietary blend.

Questions people ask

How much caffeine do studies use?
Performance studies commonly use about 2–6 mg per kg of body weight before exercise — roughly 210–420 mg for a 70 kg (154 lb) adult. Taking more is unlikely to help further. The FDA cites 400 mg a day as an amount not generally associated with dangerous effects in healthy adults.
Which caffeine supplement scores highest?
In our reviews, Transparent Labs BULK Pre-Workout scores highest at 8.5/10, followed by Legion Pulse Pre-Workout (8.3) and Gorilla Mind Gorilla Mode Pre-Workout (8.2). Scores weigh efficacy, quality, value, experience and transparency — not just the dose.
How much caffeine is in these products?
It varies by product and serving size — for example Transparent Labs BULK Pre-Workout (200 mg), Legion Pulse Pre-Workout (350 mg), Gorilla Mind Gorilla Mode Pre-Workout (200 mg per scoop). The table above lists the amount per serving for every product we've reviewed.

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