Outwork Caffeine-Free Pre-Workout
vs Pump Serum
Ingredient & Score Comparison
Last updated: Feb 2026
PwrRanks Verdict
Score Comparison
Objective scores based on ingredient dosing — 0 to 1 scale
Pump Serum's formula has 10g L-Citrulline and 4g Glycerol, which contribute to a higher pump score.
Pump Serum's formula has 3g L-Tyrosine, which contributes to a higher focus score.
Pump Serum delivers more performance per dollar than Outwork Caffeine-Free Pre-Workout — based on how both products compare to the broader pre-workout market.
Ingredient Comparison
Outwork Caffeine-Free vs Pump Serum — dosing per serving
| Ingredient | Objective | Outwork Caffeine-Free | Pump Serum |
|---|---|---|---|
| L-Citrulline | Pump | 6g | 10g |
| Taurine | Pump | 4g | 3g |
| Glycerol | Pump | — | 4g |
| Betaine Anhydrous | Pump | — | 3g |
| Arginine Nitrate | Pump | — | 3g |
| Agmatine | Pump | — | 1.5g |
| Casein Hydrolysate | Pump | — | 254mg |
| L-Tyrosine | Focus | — | 3g |
| Rhodiola Extract | Focus | 300mg | — |
| Beta-Alanine | - | 3.2g | 6.4g |
| Malic Acid | - | 1g | — |
| Calcium | - | 175mg | — |
| Black Pepper Extract | - | — | 10mg |
Who Should Buy Each
Matching products to training goals and stim tolerance
Choose Outwork Caffeine-Free If…
- No strong differentiators for this product in this comparison.
Choose Pump Serum If…
- ✓You enjoy hydration-based pump ingredients that give a swollen and full look during training
Frequently Asked Questions
Common questions about these two pre-workouts
Both are low-stim or stimulant-free (0mcg or less per serving).
More Comparisons
How PwrRanks Scores Pre-Workouts
Our methodology
PwrRanks scores every pre-workout by analyzing its ingredient label algorithmically. We generate four objective scores — Energy, Pump, Focus, and Value — that reflect what's in the tub, not how the product is marketed. Value scores are calculated using live pricing data to reflect real cost-per-serving at time of comparison.