Head to head · Pre-Workout
Cellucor C4 Original Pre-Workout vs Transparent Labs BULK Pre-Workout
Transparent Labs scores higher overall (8.5 vs 6.8 out of 10), mainly on efficacy, quality & purity, value and transparency. Cellucor still leads on experience.
Updated September 2026 from our full reviews · How we score
America's best-known budget pre-workout: 200 mg caffeine and great flavors, but beta-alanine, citrulline and creatine all sit below research doses.
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A fully transparent, Informed Choice-certified pre-workout with 8 g citrulline malate, 4 g beta-alanine and a moderate 200 mg of natural caffeine.
We may earn a commission when you buy through these links — it never affects our scores. How we make money
We may earn a commission when you buy through these links — it never affects our scores. How we make money
The short answer
Choose Cellucor if…
- Beginners wanting a moderate stimulant pre-workout
- Budget-conscious lifters
- People who value flavor variety
- You care most about experience
- You want the lower cost per serving ($1.17)
Choose Transparent Labs if…
- Daily training with moderate caffeine
- Label-readers who want clinical doses
- Athletes who want a certified product
- You care most about efficacy, quality & purity, value, transparency
Side by side
| C4 Original Pre-Workout | BULK Pre-Workout | |
|---|---|---|
| Our score | 6.8 / 10 | 8.5 / 10 |
| Efficacy (30%) | 6.0 | 8.8 |
| Quality & Purity (25%) | 7.0 | 9.0 |
| Value (20%) | 7.4 | 8.0 |
| Experience (15%) | 8.0 | 7.4 |
| Transparency (10%) | 5.5 | 9.4 |
| Form | Powder | Powder |
| Serving | 1 scoop30 servings per container | 1 full scoop30 servings per container |
| Price per serving | $1.17 | $1.67 |
| Testing & certifications | None verified | Informed Choice |
| Dietary | Sugar-free | — |
| Key ingredients |
|
|
| Flavors | 7 (Icy Blue Razz, Watermelon, Rainbow Blast…) | 8 (Blue Raspberry, Black Cherry, Strawberry Kiwi…) |
| Creator video reviews | 4 | 5 |
Pros and cons
C4 Original Pre-Workout
- 200 mg caffeine per scoop is a meaningful, well-studied dose
- Zero sugar, and Cellucor says the core flavors use no artificial colors
- About $1.17 per serving at list price ($34.99 for 30), less with Cellucor's subscription discount
- Many flavors, including licensed Jolly Rancher, Popsicle and Hawaiian Punch versions
- Uses branded ingredients (CarnoSyn beta-alanine, Velox, NO3-T creatine nitrate)
- Beta-alanine (2 g), citrulline + arginine (about 2.4 g combined) and creatine nitrate (1 g) are all below clinically studied doses
- 4.5 g proprietary blend hides the individual citrulline and arginine amounts
- C4 Original is not third-party certified (only the C4 Sport line is NSF Certified for Sport)
- Old 150 mg and new 200 mg formulas are sold side by side, which makes comparing listings confusing
BULK Pre-Workout
- Clinical doses of citrulline malate (8 g), beta-alanine (4 g) and betaine (2.5 g)
- Moderate 200 mg natural caffeine paired with 200 mg L-theanine
- Informed Choice certified (per the brand) with published third-party COAs
- No artificial sweeteners, colors or preservatives
- Wide flavor range (13 flavors on the brand site)
- Stevia-sweetened flavors are divisive; several reviewers call it hard to drink
- About $1.67 per serving, more than mass-market pre-workouts
- Boron and zinc "testosterone support" has weak evidence in healthy lifters
- Amazon listing carries a California Prop 65 warning for lead
Our verdicts
C4 Original Pre-Workout
C4 Original is a sensible pick if you mainly want a caffeine boost in a flavor you will enjoy at roughly $1 a serving. Beyond the caffeine, its key ingredients are under-dosed or hidden in a proprietary blend, so it will not match fully dosed pre-workouts for pumps or endurance. Drug-tested athletes should choose the NSF-certified C4 Sport instead.
Full review
BULK Pre-Workout
BULK is one of the best-formulated and most trustworthy pre-workouts available: clinical doses, published test results and a moderate caffeine load that suits daily training. The stevia-sweetened flavors are its main weakness, so expect a stronger, less candy-like taste than mainstream brands.
Full review