A2
Citrulline malate
- Product declaration
- L-Citrulline Malate 2:1: 8 g
- Selected studied range
- 6000 to 8000 mg
- Protocol and duration
- single acute dose, 40 to 60 minutes before training
- Studied context
- Studied for resistance-exercise repetition performance/muscular endurance, cycling performance, muscle-damage recovery, and muscle soreness. A 2021 critical review notes a single acute 8 g dose "may, albeit not consistently, increase muscular endurance-strength performance," with a meta-analysis finding an average 6.4% increase in repetitions with 6-8 g dosed 40-60 minutes pre-exercise, with a stronger trend for lower-body than upper-body exercises.
- Limitations
- The same review states there is "little evidence to advocate its use in the production and maintenance of muscular power, maximal strength, recovery of muscular function, or supporting muscular adaptations," calls cycling-performance effects "scarce," and says claims about reduced muscle soreness lack consistent support. Overall efficacy is called "ambiguous." The review also flags a real-world quality-control problem: commercial products often do not match the citrulline:malate ratio used in the research they cite.
Selected evidence: A critical review of citrulline malate supplementation and exercise performance, 2021 · Open source
A2
Beta-alanine
- Product declaration
- Beta-Alanine: 2 g
- Selected studied range
- 4000 to 6000 mg
- 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
A2
L-theanine
- Product declaration
- L-Theanine: 200 mg
- Selected studied range
- 12 to 400 mg
- Protocol and duration
- per day across trials, with most using 200 mg
- Studied context
- Studied for attention/reaction-time measures and for stress-related relaxation without sedation. A meta-analysis/systematic review of 31 randomized controlled trials (n=1,168) found a single 200 mg dose taken 30-60 minutes before testing significantly improved choice reaction time (SMD = 0.51, 95% CI 0.25-0.77); a subset of 5 RCTs in 148 healthy adults found a dose-dependent effect on rapid visual information processing and recognition visual reaction time.
- Limitations
- The review describing itself as "promising, but not completely conclusive" signals the overall evidence base has not reached firm consensus strength despite the positive reaction-time finding.
Selected evidence: Systematic review and meta-analysis of L-theanine on cognitive performance · Open source
A1
Theobromine
- Product declaration
- Theobromine: 100 mg
- Selected studied range
- No dose range selected
- Protocol and duration
- Not recorded in the selected comparison
- Studied context
- EFSA's Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF), in its 2017 opinion on xanthine alkaloids from the flavoring priority list, treats theobromine as a major metabolite of caffeine. Roughly 11% of an ingested caffeine dose converts systemically to theobromine. And states that because "only limited toxicity data in humans are available" for theobromine directly, its safety assessment leans on the extensive caffeine safety literature (EFSA's 2015 caffeine opinion) rather than an independent human-efficacy dataset for theobromine as a standalone ergogenic ingredient.
- Limitations
- No sports-performance-specific position stand or ISSN evaluation of theobromine as a standalone ergogenic ingredient was located in this research pass. EFSA's own framing acknowledges limited independent human toxicity data on theobromine itself.
Selected evidence: EFSA Flavouring Group Evaluation 49 Revision 1, 2017 · Open source
A4
Huperzine A
- Product declaration
- Huperzia-A (std. min. 1% from Huperzine serrata Root Extract): 100 mcg
- Selected studied range
- No dose range selected
- Protocol and duration
- Not recorded in the selected comparison
- Studied context
- Marketed for memory, alertness, attention, concentration, and focus, and studied preliminarily in Alzheimer's disease populations (it is used as an approved pharmaceutical for this purpose in China). The DoD's Operation Supplement Safety (OPSS) resource, reviewing the evidence base, states plainly: "No reliable scientific evidence supports the use of huperzine A to enhance cognitive performance" in healthy individuals specifically.
- Limitations
- OPSS states no reliable evidence supports cognitive-enhancement use in healthy people; the Alzheimer's Association explicitly recommends against use, especially combined with prescription drugs, citing insufficient safety data and poorly understood long-term effects.
Selected evidence: Operation Supplement Safety, huperzine A · Open source
A2
Caffeine
- Product declaration
- Total caffeine from all declared sources: 300 mg
- Selected studied range
- 140 to 420 mg
- 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