The effect of cocktail or “pre-workout” supplements containing L-arginine nitrate and caffeine are equivocal with anaerobic performance. The purpose of this study was to compare anaerobic performance and blood flow of pre-workout supplement containing L-arginine-nitrate and caffeine-to-caffeine and placebo. In a randomized, double-blind study, 12 resistance-trained males (caffeine users) completed three trials. Biodex concentric-concentric elbow-flexion and extension (5-sets, 10-repetitions). Ultrasound measured brachial blood flow (M-Vel, V- r2 and V-C). Statistical analyses revealed a significant difference in total dynamic work PRE-PLA (P<0.0001) and CAF-to-PLA (P<0.0001) but not PRE-to-CAF (P=0.9581). Furthermore, a significant difference V- r2 PRE-to-CAF (P=0.0391) and PLA-to-CAF (P=0.0070) and M-Vel PRE-to-CAF (P=0.0281). Conclusion, PRE did not differ CAF in strength measures other than a difference in M-Vel. PRE compared to PLA were not statically different in blood flow. The study illustrated no improvement beyond individual ingredient. This research may be useful for future cocktail supplement and Nitric Oxide research.