Cellucor C4 Original

Protocol and duration

per day in divided doses, for at least 2 to 4 weeks, not as a single pre-workout dose

Studied context

Studied for high-intensity exercise capacity in the 60-240 second range via elevation of muscle carnosine, which acts as an intracellular pH buffer against acidosis. ISSN 2015 position stand: greatest performance benefits in "open end-point" tasks/time trials lasting 1-4 minutes; some benefit noted in aerobic exercise up to roughly 25 minutes; attenuation of neuromuscular fatigue, particularly noted in older adults.

Limitations

Strength/resistance-training outcomes remain mixed; training volume may increase without a clear strength gain. Tasks under 60 seconds do not show benefit. Endurance benefit beyond about 25 minutes is not established. Long-term safety data beyond roughly a year, and effects in special/tactical populations, are flagged as needing more research.

Selected evidence: ISSN position stand on beta-alanine, 2015 · Open source

Protocol and duration

per day, in the studies NIH ODS summarizes

Studied context

Studied as a nitric-oxide pathway precursor (converted to arginine via the urea cycle) for aerobic exercise performance measures such as oxygen-uptake (VO2) kinetics, blood lactate, and rate of perceived exertion, and for acute resistance-exercise performance and muscle oxygenation. NIH ODS describes evidence for enhancing performance as limited, with few studies and conflicting results.

Limitations

A 2022 systematic review/meta-analysis found no significant benefit for endurance-performance outcomes specifically. A single 8 g acute dose did not enhance isometric force production, muscle endurance, or muscle-oxygenation parameters in one resistance-exercise study. NIH ODS characterizes overall performance-enhancement evidence as limited.

Selected evidence: NIH ODS, Dietary Supplements for Exercise and Athletic Performance · Open source

Protocol and duration

per day across the studies NIH ODS reviewed

Studied context

Plain L-arginine has been studied for exercise-related vasodilation, blood flow, and exercise metabolites, per NIH ODS. The branded ingredient Nitrosigine (inositol-stabilized arginine silicate) has been studied in a series of company-funded and academic trials for acute and sustained plasma arginine elevation, exercise-induced muscle damage markers (serum creatine kinase), perceived energy, and post-exercise cognitive performance. A randomized double-blind study (PMC5133120) reported cognitive-test-score changes (including RBANS measures) in healthy physically active adults.

Limitations

NIH ODS states plain arginine supplementation shows "little to no effect on vasodilation, blood flow, or exercise metabolites" and "little to no enhancement of athletic performance" overall. A notably weak evidence verdict for the free amino acid form. For Nitrosigine specifically, this research pass relied on the trademark holder's own technical page and holder-affiliated trial write-ups (A3-level sourcing); no independent NIH/FDA/EFSA evaluation of Nitrosigine's efficacy claims was located.

Selected evidence: NIH ODS, Dietary Supplements for Exercise and Athletic Performance · Open source

Protocol and duration

Not recorded in the selected comparison

Studied context

PeptiPump is described (per Nuritas, the trademark holder, and secondary trade coverage) as a network of peptides identified within lentil-protein hydrolysate using Nuritas's "Magnifier AI" discovery platform, selected for angiotensin-converting-enzyme (ACE) inhibitory activity, with a proposed mechanism of preserving bradykinin and reducing ADMA to support nitric-oxide-pathway vasodilation and muscle blood flow. It has been incorporated into Nutrabolt/Cellucor's C4 pre-workout line.

Limitations

This is the thinnest evidence base found in this entire research set. A trade-press ingredient explainer (PricePlow) explicitly states: "As of March 2024, there are still no peer-reviewed, journal-published research on PeptiPump itself... While a published clinical trial on PeptiPump was not available at the time of writing, one is registered." All mechanistic claims (ACE inhibition, bradykinin preservation, ADMA reduction, mTOR pathway activity) are described as predictions from Nuritas's AI platform and extrapolations from general ACE-inhibitory-peptide literature (citing unrelated studies such as Hata et al. 1996 and Barbosa et al. 2006), not findings from a human trial of PeptiPump itself.

Selected evidence: Trade-press ingredient explainer · Open source

Protocol and duration

per day over 28 days, in the one controlled trial located

Studied context

A 2016 randomized, placebo-controlled study (Galvan et al., Journal of the International Society of Sports Nutrition) studied creatine nitrate for acute hemodynamic/blood-marker safety and for chronic effects on training performance (bench press lifting volume, power output) compared with creatine monohydrate and placebo.

Limitations

The same study found that only creatine monohydrate produced sustained increases in intramuscular creatine concentration through day 28; the high-dose creatine-nitrate group's initial increase "abated" by the end of the study. The evidence base for creatine nitrate is far smaller and shorter-duration than for monohydrate; long-term safety data comparable to monohydrate's multi-year record does not exist.

Selected evidence: Galvan et al., dose dependent creatine nitrate supplementation, 2016 · Open source

Protocol and duration

2 to 6 mg per kg body mass, 15 to 60 minutes before exercise, shown here for a 70 kg adult

Studied context

Studied for endurance-type aerobic exercise (moderate to large ergogenic effect, most consistent evidence category per ISSN 2021), muscular endurance and movement velocity in resistance exercise (small to moderate effects), sprinting/jumping/throwing (2-7% improvements), and cognitive attention/vigilance under fatigue. NIH ODS notes it "might enhance performance in endurance-type activities... And intermittent, long-duration activities."

Limitations

Minimal effective dose remains unclear. Repeated-sprint performance benefit is inconsistent and the ISSN position stand says this "requires further research." Effects of habitual/chronic caffeine use on the ergogenic response are described as equivocal.

Selected evidence: ISSN position stand on caffeine and exercise performance, 2021, with NIH ODS · Open source