Product Image

C4 Ultimate Orange Mango

Nutrabolt
4.7
★ ★ ★ ★ ★
(347 ratings)
Huperzine 50 mcg
Caffeine 300 mg
Alpha-GPC 200 mg
Product Image
Score59
A broadly dosed pre-workout with meaningful performance and focus ingredients. The citrulline-matrix composition and active Alpha-GPC yield are not fully clear is the key trade-off alongside a costly serving.
How scoring works
Quantity:326 Gram(s) • (20 servings)
Goals:
Energy
Muscle Gain
Productivity Boost
Metabolism Boost
Weight Loss
Mental Focus
Cognitive Support
Brain Health

Score 59

A broadly dosed pre-workout with meaningful performance and focus ingredients. The citrulline-matrix composition and active Alpha-GPC yield are not fully clear is the key trade-off alongside a costly serving.
How scoring works

Also available as

1 option
320 servings • Icy Blue Razz Caffeine 300 mg, Huperzine 50 mcg +1 more • 320 Gram(s) • 20 servings $39.99 ($1.99 per serving)
$39.99($1.99 per serving)
iHerb
$ 39.99
Report prices

Analysis

A six-gram citrulline matrix, CarnoSyn beta-alanine, two creatine forms, taurine, tyrosine, and 300 mg caffeine covers pump, training capacity, and energy in one serving. An unspecified-yield 200 mg AlphaSize plus 50 mcg Huperzine A supports focus adds a cognitive component, though stimulant effects will drive much of the immediate experience.

The formula fits energy, fitness, muscle, and productivity goals better than broad brain health. Strong dosing may suit experienced pre-workout users but can be excessive for stimulant-sensitive people.

Most important actives have stated amounts, supporting direct comparison. The citrulline-matrix composition and active Alpha-GPC yield are not fully clear remains the main transparency problem, while a costly serving weakens practical value.

Who is it for
  • Experienced adults seeking a high-stimulant pre-workout
  • Users wanting pump, training, and focus support together
  • People who can avoid other caffeine sources
Best for
  • Workout energy
  • Training performance
  • Short-term mental focus

Pros

  • Covers several performance pathways
  • An unspecified-yield 200 mg AlphaSize plus 50 mcg Huperzine A supports focus
  • Discloses the main stimulant amount

Cons

  • The citrulline-matrix composition and active Alpha-GPC yield are not fully clear
  • a costly serving
  • Not suited to caffeine-sensitive users

Warnings

  • Caffeine, theacrine, and rauwolfia together create a strong caffeine can cause jitteriness, rapid heartbeat, anxiety, or sleep disruption, especially with other stimulants.
  • Beta-alanine commonly causes harmless tingling, while the stimulant load may be harder to tolerate.
  • Rauwolfia can raise heart rate and blood pressure and should not be combined with stimulant or blood-pressure medicines without review.

Nutrient quality

69 High impact

Substantial performance ingredients create strong acute workout and focus support. An aggressive stimulant stack, modest cognitive doses, and a partly hidden pump matrix reduce balance.

.

Ingredient transparency

59 Moderate impact

Most major active totals are disclosed and several branded forms are identified. The hidden pump matrix, incomplete usage guidance, and absent flavor-system details limit transparency.

.

Customer satisfaction

65 High impact

The supplied aggregate satisfaction signal is favorable and has some support from its response volume. Specific experience details are absent, so complaint patterns and purpose fit cannot be confirmed.

.

Value for money

39 Lower impact

The core performance formula provides real functional value. Premium serving positioning and uneven dose depth make the product less competitive.

.
Report analysis

Goals

Energy
Energy
Impact
Highest effect
A Goal FitA Strength of SupportA- CoverageB+ Formula Quality
Caffeine · 300 mgCreatine · 1 Gram(s)

Caffeine, beta-alanine, citrulline, creatine, taurine, and tyrosine provide strong acute workout-energy and performance support. Most key amounts are clearly disclosed and reach meaningful levels.

The high stimulant load may cause insomnia, anxiety, elevated heart rate, or blood pressure effects. Rauwolfia and multiple cognitive stimulants make the formula unsuitable for stimulant-sensitive users.

Study evidence
Caffeine Supportive 68 studies
Creatine Supportive 49 studies
Muscle Gain
Muscle Gain
Impact
Highest effect
A- Goal FitB Strength of SupportA- CoverageB- Formula Quality
Creatine · 1 Gram(s)Caffeine · 300 mgBeta-Alanine · 3.2 Gram(s)

Citrulline, beta-alanine, and two creatine forms provide strong training-volume, fatigue-buffering, and power support. Beta-alanine is well dosed, while the combined creatine amount is below the usual daily amount used for muscle and strength gains.

The six-gram pump blend does not separate citrulline from its matrix components, and several focus ingredients are modestly dosed. The 300 mg caffeine amount plus theacrine and rauwolfia can raise heart rate, anxiety, or sleep disruption in stimulant-sensitive users.

Study evidence
Caffeine Supportive 31 studies
Creatine Supportive 136 studies
Taurine Not classified

No linked studies yet.

Productivity Boost
Productivity Boost
Impact
Highest effect
A- Goal FitB+ Strength of SupportA- CoverageC+ Formula Quality
Creatine · 1 Gram(s)Huperzine · 50 mcgAlpha-GPC · 200 mgCaffeine · 300 mg

The stimulant-centered stack offers strong acute alertness with added tyrosine, alpha-GPC, and huperzine A for cognitive support. Several performance ingredients broaden the formula but contribute less directly to desk-based productivity.

Key active amounts are disclosed, although the citrulline matrix remains blended and some cognitive actives are modestly dosed. The high caffeine load combined with theacrine and rauwolfia may cause jitters, rapid heartbeat, higher blood pressure, anxiety, or sleep disruption.

Study evidence
Alpha-GPC Supportive 2 studies
Caffeine Supportive 108 studies
Huperzine No effect 1 study
Metabolism Boost
Metabolism Boost
Impact
Highest effect
A- Goal FitB+ Strength of SupportB CoverageC+ Formula Quality
Creatine · 1 Gram(s)Caffeine · 300 mg

Caffeine directly increases short-term energy expenditure and fat mobilization. The strong amount is likely to be noticeable but does not create a lasting change in baseline metabolism.

The caffeine dose and companion stimulants are clearly disclosed. Combining caffeine, theacrine, and rauwolfia may increase jitteriness, rapid heartbeat, or sleep disruption.

Study evidence
Caffeine Disputed 40 studies
Weight Loss
Weight Loss
Impact
Highest effect
A- Goal FitA- Strength of SupportB- CoverageB- Formula Quality
Creatine · 1 Gram(s)Caffeine · 300 mg

Caffeine can increase thermogenesis and training output, while creatine may help preserve performance during a calorie deficit. Citrulline and beta-alanine add substantial workout-focused support.

The formula stacks 300 mg caffeine with theacrine and Rauwolfia, which can increase jitters, rapid heartbeat, or sleep disruption. Creatine totals 2 g, below common daily loading-free targets, and the product has no satiety ingredient.

Study evidence
Caffeine Disputed 14 studies
Creatine No effect 27 studies
Mental Focus
Mental Focus
Impact
High effect
A- Goal FitB+ Strength of SupportB CoverageD+ Formula Quality
Alpha-GPC · 200 mgCreatine · 1 Gram(s)Caffeine · 300 mgHuperzine · 50 mcg

Caffeine, N-acetyl-L-tyrosine, Alpha-GPC, and huperzine A provide a strong acute-focus framework. Alertness, catecholamine support, and cholinergic signaling are all represented.

The stimulant load is aggressive, while active Alpha-GPC yield and tyrosine depth are modest. Caffeine combined with theacrine and rauwolfia may increase jitters, rapid heartbeat, and sleep disruption, especially for stimulant-sensitive users.

Study evidence
Alpha-GPC Supportive 1 study
Caffeine Supportive 128 studies
Huperzine Not classified

No linked studies yet.

Ingredients

IngredientAmount per serving
Calories
5 Calorie(s)
Total Carbohydrates
1 Gram(s)
C4 Super Citrulline Pump Matrix
6 Gram(s)
CarnoSyn (Beta-Alanine)
 3.2 Gram(s)
Creatine Hydrochloride
1 Gram(s)
Creatine Nitrate (NO3-T)
 1 Gram(s)
Taurine
1 Gram(s)
N-Acetyl-L-Tyrosine
400 mg
Caffeine Anhydrous
300 mg
AlphaSize
200 mg
Theacrine
62.5 mg
Rauwolfia vomitoria root extract
1 mg
Huperzine A (Toothed Clubmoss extract)
 50 mcg
Adults 18–50 Women
Report overview
Huperzine (Toothed Clubmoss extract) · 50 mcg OverallScore77
B- Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyB- Value

The powder discloses 50 mcg Huperzine A from toothed clubmoss extract, meeting the effective range. Mixing a microgram alkaloid into a large scoop may reduce dose consistency, and no cycling guidance is supplied. Alpha-GPC adds cognitive value, while 300 mg caffeine and rauwolfia may be too stimulating for sensitive users.

View ingredientView products
Caffeine · 300 mg OverallScore69
B Active Ingredient Quality & BioavailabilityA Dose, Safety & Label TransparencyF Value

Caffeine anhydrous provides a well-defined source, but the formula has no sustained-release technology. The strong caffeine dose is clearly stated, and theacrine plus rauwolfia are also disclosed with exact amounts. Combining these stimulants may increase jitters, rapid heartbeat, or sleep disruption, while the very high serving cost offers poor economic efficiency.

View ingredientView products
Alpha-GPC · 200 mg OverallScore50
C+ Active Ingredient Quality & BioavailabilityF Dose, Safety & Label TransparencyD- Value

AlphaSize provides a branded, quality-controlled source, but the single listed amount does not clarify active yield. Assuming half active material leaves the dose below the range for acute cognitive support. The loose powder offers little moisture protection, while 300 mg caffeine plus rauwolfia adds a substantial stimulant load that may not suit stimulant-sensitive users.

View ingredientView products
Loading alternative details
77 Performance

Pulse Fruit Punch

Legion
<p>A deeper performance formula combines citrulline malate, beta-alanine, betaine, Alpha-GPC, theanine, and caffeine at disclosed amounts. It provides stronger pump, endurance, and focus coverage than the original, although the high caffeine amount may not suit stimulant-sensitive users.</p>
79 Performance

High-Performance Pre-Workout Pineapple Strawberry

Pre JYM
<p>A broad, fully disclosed formula adds citrulline malate, creatine HCl, beta-alanine, betaine, taurine, branched-chain amino acids, tyrosine, Alpha-GPC, caffeine, and huperzine. It covers more aspects of workout performance and focus than the original, though its caffeine amount remains high.</p>
72 Performance

Genius Consciousness Watermelon

The Genius Brand
<p>A focused cognitive blend supplies Alpha-GPC, acetyl-L-carnitine, lion’s mane, tyrosine, phosphatidylserine, caffeine, and methyliberine. It is a better choice when mental focus is the priority, but it does not replace the original’s pump or muscular-performance ingredients.</p>
75 Budget

Hydroxycut Hardcore Super Elite

MuscleTech
<p>A much lower serving cost comes with caffeine, choline, green coffee extract, alpha-lipoic acid, and huperzine for energy and metabolism support. It lacks the original-style citrulline, beta-alanine, and creatine foundation, so it is a better budget fit when stimulation matters more than complete workout support.</p>
72 Budget

Seventh Gear Your Mom's Lemonade

Axe & Sledge Supplements
<p>A lower serving cost retains beta-alanine, betaine, creatine, Alpha-GPC, huperzine, and several stimulant forms. The performance ingredients are modestly dosed, but the formula keeps useful energy and focus coverage while improving cost efficiency.</p>
80 Budget

High-Performance Pre-Workout Rainbow Sherbet

Pre JYM
<p>The lower serving cost includes disclosed citrulline malate, creatine HCl, beta-alanine, betaine, taurine, amino acids, tyrosine, Alpha-GPC, caffeine, and huperzine. That broad formula supports training, energy, and focus without giving up the main functions of the original.</p>
78 Value

High-Performance Pre-Workout Tangerine

Pre JYM
<p>A lower serving cost buys a fully disclosed mix of citrulline malate, creatine HCl, beta-alanine, betaine, taurine, amino acids, tyrosine, Alpha-GPC, caffeine, and huperzine. The broad training and focus coverage makes it a stronger value than the original, with high caffeine as the main caution.</p>
66 Value

Bucked Up Pre-Workout 'Merica Rocket Pop

DAS Labs
<p>A lower serving cost still provides citrulline malate, beta-alanine, caffeine, Alpha-GPC, and taurine in a disclosed formula. Citrulline supports its value for pump-focused training, while the lighter beta-alanine and Alpha-GPC amounts are meaningful trade-offs.</p>
66 Value

Pre-Workout Blood Raz

Bucked Up
<p>A more economical serving retains citrulline malate, beta-alanine, caffeine, Alpha-GPC, and taurine for pump, energy, and focus. The formula is less comprehensive than the strongest candidates, but its disclosed core ingredients make it a practical value alternative to the original.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Effect of Caffeine on Golf Performance and Fatigue during a Competitive Tournament.
    Mumford PW; Tribby AC; Poole CN; Dalbo VJ; Scanlan AT; Moon JR; Roberts MD; Young KC · Medicine and science in sports and exercise · 2016
    Randomized trial12 participantsEnergy forCaffeine
  2. Differential cognitive effects of energy drink ingredients: caffeine, taurine, and glucose.
    Giles GE; Mahoney CR; Brunyé TT; Gardony AL; Taylor HA; Kanarek RB · Pharmacology, biochemistry, and behavior · 2013
    Randomized trial48 participantsEnergy forCaffeine
  3. Caffeine administration at night during extended wakefulness effectively mitigates performance impairment but not subjective assessments of fatigue and sleepiness.
    Paech GM; Banks S; Pajcin M; Grant C; Johnson K; Kamimori GH; Vedova CB · Pharmacology, biochemistry, and behavior · 2017
    Randomized trial24 participantsEnergy forCaffeine
  4. No effects of caffeine on cycling to exhaustion and perceptual responses in non-caffeine-restricted subjects.
    Weippert M; Behrens M; Schlegel M; Schröder T; Tillmann M; Rühe N; Römer R; Mau-Möller A; Bruhn S · Journal of the International Society of Sports Nutrition · 2025
    Randomized trial56 participantsEnergy Fitness forCaffeine
  5. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features.
    Juliano LM; Griffiths RR · Psychopharmacology · 2005
    Systematic review66 studies pooledEnergy forCaffeine
  6. Effect of caffeine ingestion on cycling performance: a systematic review and meta-analysis.
    Wu J; Xu K; Yin M; Ding X; Wang T; Zhang Q; Wu X; Xiao N · Frontiers in nutrition · 2026
    Meta-analysis226 participants20 studies pooledFitness forCaffeine
  7. Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.
    Wang Z; Qiu B; Gao J; Del Coso J · Nutrients · 2023
    Meta-analysis254 participants21 studies pooledFitness forCaffeine
  8. Acute Effects of Caffeine Supplementation on Physical Performance, Physiological Responses, Perceived Exertion, and Technical-Tactical Skills in Combat Sports: A Systematic Review and Meta-Analysis.
    Delleli S; Ouergui I; Messaoudi H; Trabelsi K; Ammar A; Glenn JM; Chtourou H · Nutrients · 2022
    Meta-analysis26 studies pooledFitness forCaffeine
  9. Caffeine, CYP1A2 Genotype, and Endurance Performance in Athletes.
    Guest N; Corey P; Vescovi J; El-Sohemy A · Medicine and science in sports and exercise · 2019
    Randomized trial101 participantsFitness forCaffeine
  10. Activity of Choline Alphoscerate on Adult-Onset Cognitive Dysfunctions: A Systematic Review and Meta-Analysis.
    Sagaro GG; Traini E; Amenta F · Journal of Alzheimer's disease : JAD · 2023
    Meta-analysis8 studies pooledCognitive Support Brain Health forAlpha-GPC
  11. Comparative study of choline alfoscerate as a combination therapy with donepezil: A mixed double-blind randomized controlled and open-label observation trial.
    Lee W; Kim M · Medicine · 2024
    Randomized trial119 participantsCognitive Support Brain Health forAlpha-GPC
  12. Effect of Choline Alfoscerate on the Progression From Mild Cognitive Impairment to Dementia: Distributed Network Analysis of a Multicenter Korean Database Using a Common Data Model.
    Pyun JM; Lee I; Lee K; Kim MH; Park C; Yang HJ · Dementia and neurocognitive disorders · 2024
    Cohort study3,062 participantsCognitive Support forAlpha-GPC
  13. Huperzine a in the treatment of Alzheimer's disease and vascular dementia: a meta-analysis.
    Xing SH; Zhu CX; Zhang R; An L · Evidence-based complementary and alternative medicine : eCAM · 2014
    Meta-analysis825 participants10 studies pooledCognitive Support Brain Health forHuperzine
  14. Adjunctive huperzine A for cognitive deficits in schizophrenia: a systematic review and meta-analysis.
    Zheng W; Xiang YQ; Li XB; Ungvari GS; Chiu HF; Sun F; D'Arcy C; Meng X; Xiang YT · Human psychopharmacology · 2017
    Meta-analysis1,117 participants12 studies pooledCognitive Support forHuperzine
  15. Huperzine A associated with improved early postoperative cognitive function after neurosurgery under general anesthesia: a randomized clinical trial.
    Zhang Z; Shen Y; Li J; Tang Y; Zhou P; Ying T; Mo R; Ru Z; Zhao G; Zhu J; Li S; Zhao H · International journal of surgery (London, England) · 2026
    Randomized trial123 participantsCognitive Support Brain Health forHuperzine
  16. Huperzine A for vascular dementia.
    Hao Z; Liu M; Liu Z; Lv D · The Cochrane database of systematic reviews · 2009
    Systematic review14 participants1 studies pooledCognitive Support forHuperzine
  17. A phase II trial of huperzine A in mild to moderate Alzheimer disease.
    Rafii MS; Walsh S; Little JT; Behan K; Reynolds B; Ward C; Jin S; Thomas R; Aisen PS; Alzheimer's Disease Cooperative Study · Neurology · 2011
    Randomized trial210 participantsCognitive Support forHuperzine
  18. Effects of choline alfoscerate on cognitive function and quality of life in type 2 diabetes: A double-blind, randomized, placebo-controlled trial.
    Sohn M; Park YH; Lim S · Diabetes, obesity & metabolism · 2025
    Randomized trial36 participantsBrain Health Cognitive Support forAlpha-GPC
  19. Acute Alpha-Glycerylphosphorylcholine Supplementation Enhances Cognitive Performance in Healthy Men.
    Kerksick CM · Nutrients · 2024
    Randomized trial20 participantsBrain Health Mental Focus Productivity Boost forAlpha-GPC
  20. Cognitive improvement in mild to moderate Alzheimer's dementia after treatment with the acetylcholine precursor choline alfoscerate: a multicenter, double-blind, randomized, placebo-controlled trial.
    De Jesus Moreno Moreno M · Clinical therapeutics · 2003
    Randomized trial261 participantsBrain Health forAlpha-GPC
  21. Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial.
    Rae C; Digney AL; McEwan SR; Bates TC · Proceedings. Biological sciences · 2003
    Randomized trial45 participantsBrain Health forCreatine
  22. Creatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG.
    Hersch SM; Gevorkian S; Marder K; Moskowitz C; Feigin A; Cox M; Como P; Zimmerman C; Lin M; Zhang L; Ulug AM; Beal MF; Matson W; Bogdanov M; Ebbel E; Zaleta A; Kaneko Y; Jenkins B; Hevelone N; Zhang H; Yu H; Schoenfeld D; Ferrante R; Rosas HD · Neurology · 2006
    Randomized trial64 participantsBrain Health forCreatine
  23. Creatine supplementation and cognitive performance in elderly individuals.
    McMorris T; Mielcarz G; Harris RC; Swain JP; Howard A · Neuropsychology, development, and cognition. Section B, Aging, neuropsychology and cognition · 2008
    Randomized trial32 participantsBrain Health forCreatine
  24. Effects of high-load, velocity-intentional variable resistance training combined with creatine supplementation on neuroplasticity, oxidative stress, inflammation, physical function, cognitive performance and quality of life in older adults: A randomized, double-blind, placebo-controlled trial.
    Fernandez-Garrido J; Martin EG; Saez-Berlanga A; Gargallo-Bayo P; Gene-Morales J; Alix-Fages C; Jiménez-Martínez P; Caballero O; Salvador-Palmer R; Colado JC · Experimental gerontology · 2026
    Randomized trial103 participantsBrain Health forCreatine
  25. Single-Dose Creatine Reduces Sleep Deprivation-Induced Deterioration in Cognitive Performance.
    Gordji-Nejad A; Matusch A; Hengstler L; Beer S; Kroll T; Klein S; Elmenhorst D; Bauer A; Drzezga A · Nutrients · 2026
    Randomized trial29 participantsBrain Health forCreatine
  26. [Clinical efficacy and safety of huperzine Alpha in treatment of mild to moderate Alzheimer disease, a placebo-controlled, double-blind, randomized trial].
    Zhang Z; Wang X; Chen Q; Shu L; Wang J; Shan G · Zhonghua yi xue za zhi · 2002
    Randomized trial202 participantsBrain Health Cognitive Support forHuperzine
  27. Treatment with Huperzine A improves cognition in vascular dementia patients.
    Xu ZQ; Liang XM; Juan-Wu; Zhang YF; Zhu CX; Jiang XJ · Cell biochemistry and biophysics · 2012
    Randomized trial78 participantsBrain Health forHuperzine
  28. Huperzine-A response to cognitive impairment and task switching deficits in patients with Alzheimer's disease.
    Gul A; Bakht J; Mehmood F · Journal of the Chinese Medical Association : JCMA · 2019
    Randomized trial100 participantsBrain Health forHuperzine
  29. [Gliatilin in the Treatment of Cognitive Impairments Not Reaching the Level of Dementia: Meta-Analysis and Systematic Review].
    Voznyuk IA; Nepomnyashchiy IS; Kutkova AK; Tokareva DV; Prokhorova MV; Ovdiienko OA; Shusharina NN · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova · 2025
    Meta-analysis10 studies pooledCognitive Support forAlpha-GPC
  30. Vertical Association Between Dietary Total Choline and L-alpha-glycerylphosphorylcholine and the Cognitive Function in Chinese Adults Aged over 55, Result from China Health and Nutrition Survey 1997-2018.
    Guan F; Jia X; Huang F; Zhang J; Wei Y; Li L; Bai J; Wang H · Nutrients · 2024
    Cohort study7,659 participantsCognitive Support forAlpha-GPC
  31. [Drug evaluation of huperzine A in the treatment of senile memory disorders].
    Zhang RW; Tang XC; Han YY; Sang GW; Zhang YD; Ma YX; Zhang CL; Yang RM · Zhongguo yao li xue bao = Acta pharmacologica Sinica · 1992
    Randomized trial56 participantsCognitive Support forHuperzine
  32. Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine.
    Haskell CF; Kennedy DO; Wesnes KA; Scholey AB · Psychopharmacology · 2005
    Randomized trial48 participantsEnergy forCaffeine
  33. Caffeine-containing energy drink improves physical performance of elite rugby players during a simulated match.
    Del Coso J; Ramírez JA; Muñoz G; Portillo J; Gonzalez-Millán C; Muñoz V; Barbero-Álvarez JC; Muñoz-Guerra J · Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme · 2016
    Randomized trial26 participantsEnergy forCaffeine
  34. Does Single or Combined Caffeine and Taurine Supplementation Improve Athletic and Cognitive Performance without Affecting Fatigue Level in Elite Boxers? A Double-Blind, Placebo-Controlled Study.
    Ozan M; Buzdagli Y; Eyipinar CD; Baygutalp NK; Yüce N; Oget F; Kan E; Baygutalp F · Nutrients · 2022
    Randomized trial20 participantsEnergy forCaffeine
  35. Trait Energy and Fatigue Modify the Effects of Caffeine on Mood, Cognitive and Fine-Motor Task Performance: A Post-Hoc Study.
    Fuller DT; Smith ML; Boolani A · Nutrients · 2021
    Randomized trialEnergy forCaffeine
  36. Synergistic effects of creatine, carbs, protein on repeated sprint performance.
    Wang Y; Wei H; Cheng X; Chen Z · Scientific reports · 2026
    Randomized trial60 participantsEnergy forCreatine
  37. The Effects of Creatine Monohydrate Supplementation on Recovery from Eccentric Exercise-Induced Muscle Damage: A Double-Blind, Randomized, Placebo-Controlled Trial Considering Sex and Age Differences.
    Yamaguchi S; Inami T; Nishioka T; Morito A; Ishiyama K; Murayama M · Nutrients · 2025
    Randomized trial40 participantsEnergy forCreatine
  38. The Effect of Prior Creatine Intake for 28 Days on Accelerated Recovery from Exercise-Induced Muscle Damage: A Double-Blind, Randomized, Placebo-Controlled Trial.
    Yamaguchi S; Inami T; Ishida H; Morito A; Yamada S; Nagata N; Murayama M · Nutrients · 2024
    Randomized trial20 participantsEnergy forCreatine
  39. Creatine supplementation attenuates the rate of fatigue development during intermittent isometric exercise performed above end-test torque.
    Abdalla LHP; Broxterman RM; Greco CC; Denadai BS · Experimental physiology · 2021
    Randomized trial16 participantsEnergy forCreatine
  40. The effect of continuous low dose creatine supplementation on force, power, and total work.
    Burke DG; Silver S; Holt LE; Smith Palmer T; Culligan CJ; Chilibeck PD · International journal of sport nutrition and exercise metabolism · 2000
    Randomized trial41 participantsEnergy forCreatine
  41. Acute Effects of Caffeine Supplementation on Movement Velocity in Resistance Exercise: A Systematic Review and Meta-analysis.
    Raya-González J; Rendo-Urteaga T; Domínguez R; Castillo D; Rodríguez-Fernández A; Grgic J · Sports medicine (Auckland, N.Z.) · 2021
    Meta-analysis12 studies pooledFitness forCaffeine
  42. Sex Differences in the Ergogenic Response of Acute Caffeine Intake on Muscular Strength, Power and Endurance Performance in Resistance-Trained Individuals: A Randomized Controlled Trial.
    Montalvo-Alonso JJ; Ferragut C; Del Val-Manzano M; Valadés D; Roberts J; Pérez-López A · Nutrients · 2024
    Randomized trial76 participantsFitness forCaffeine
  43. Can I Have My Coffee and Drink It? A Systematic Review and Meta-analysis to Determine Whether Habitual Caffeine Consumption Affects the Ergogenic Effect of Caffeine.
    Carvalho A; Marticorena FM; Grecco BH; Barreto G; Saunders B · Sports medicine (Auckland, N.Z.) · 2022
    Meta-analysis60 studies pooledFitness forCaffeine
  44. Creatine in combination with resistance training and improvement in muscle strength: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusFitness forCreatine
  45. Effect of creatine and weight training on muscle creatine and performance in vegetarians.
    Burke DG; Chilibeck PD; Parise G; Candow DG; Mahoney D; Tarnopolsky M · Medicine and science in sports and exercise · 2004
    Randomized trial42 participantsFitness forCreatine
  46. Long-term creatine intake is beneficial to muscle performance during resistance training.
    Vandenberghe K; Goris M; Van Hecke P; Van Leemputte M; Vangerven L; Hespel P · Journal of applied physiology (Bethesda, Md. : 1985) · 1998
    Randomized trial19 participantsFitness forCreatine
  47. Effects of Combined Versus Single Supplementation of Creatine, Beta-Alanine, and L-Citrulline During Short Sprint Interval Training on Basketball Players' Performance: A Double-Blind Randomized Placebo-Controlled Trial.
    Li M; Sheykhlouvand M · International journal of sports physiology and performance · 2025
    Randomized trial48 participantsFitness forCreatine
  48. The Additive Effects of Creatine Supplementation and Exercise Training in an Aging Population: A Systematic Review of Randomized Controlled Trials.
    Stares A; Bains M · Journal of geriatric physical therapy (2001) · 2021
    Systematic review17 studies pooledFitness forCreatine
  49. Taurine supplementation enhances anaerobic power in elite speed skaters: A double-blind, randomized, placebo-controlled, crossover study.
    Buzdağlı Y; Eyipınar CD; Öget F; Şıktar E; Forbes SC; Tekin A · Biology of sport · 2023
    Randomized trial30 participantsFitness forTaurine
  50. The effect of acute taurine ingestion on 3-km running performance in trained middle-distance runners.
    Balshaw TG; Bampouras TM; Barry TJ; Sparks SA · Amino acids · 2013
    Randomized trial8 participantsFitness forTaurine
  51. Effects of different doses of taurine supplementation on repeated-sprint performance after exhaustive exercise in a high temperature and humidity environment.
    Cheng X; Lin Y; Li Z · Frontiers in nutrition · 2026
    Randomized trial16 participantsFitness forTaurine
  52. Oral taurine improves critical power and severe-intensity exercise tolerance.
    Waldron M; Patterson SD; Jeffries O · Amino acids · 2020
    Randomized trial12 participantsFitness forTaurine
  53. Acute taurine supplementation enhances thermoregulation and endurance cycling performance in the heat.
    Page LK; Jeffries O; Waldron M · European journal of sport science · 2019
    Randomized trial11 participantsFitness forTaurine
  54. Effects of modafinil and caffeine on night-time vigilance of air force crewmembers: A randomized controlled trial.
    Wingelaar-Jagt YQ; Bottenheft C; Riedel WJ; Ramaekers JG · Journal of psychopharmacology (Oxford, England) · 2023
    Randomized trial32 participantsMental Focus forCaffeine
  55. Acute effects of caffeine on attention: a comparison of non-consumers and withdrawn consumers.
    Smith AP; Christopher G; Sutherland D · Journal of psychopharmacology (Oxford, England) · 2013
    Randomized trial70 participantsMental Focus forCaffeine
  56. Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation.
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    Randomized trial32 participantsWeight Loss forCreatine