Power Output

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect power output

Grade	Level of Evidence [show legend]
	Robust research conducted with repeated double-blind clinical trials
	Multiple studies where at least two are double-blind and placebo controlled
	Single double-blind study or multiple cohort studies
	Uncontrolled or observational studies only

Level of Evidence ? The amount of high quality evidence. The more evidence, the more we can trust the results.	Outcome	Magnitude of effect ? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.	Consistency of research results ? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.	Notes
	Creatine	Strong	Very High See all 66 studies	Creatine is the reference compound for power improvement, with numbers from one meta-analysis to assess potency being "Able to increase a 12% improvement in strength to 20% and able to increase a 12% increase in power to 26% following a training regiment using creatine monohydrate".
	HMB	-	Moderate See all 12 studies	Limited evidence supports the increase in power output, which may be due to chance; more often than not, there is no significant influence
	Sodium Bicarbonate	-	Moderate See all 28 studies	Although technically an increase in average power output may occur during exercise associated with the 'burn' (metabolic acidosis) to the degree of 1-2%, saying this is an inherent or reliable increase in power would be misleading; it is an attenuation of the decrease in power that acidosis is able to induce
	Caffeine
	Beta-Alanine
	Chromium
	Colostrum
	Dehydroepiandrosterone
	L-Carnitine
	Trimethylglycine
	Whey Protein
	Alpha-GPC
	Ashwagandha
	Spirulina
	Alcohol
	Clenbuterol
	Resveratrol
	Terminalia arjuna
	Theaflavins
	Ursolic Acid
	Velvet Antler
	Alanylglutamine
	Anatabine
	Arachidonic acid
	Arginine
	Astaxanthin
	Branched Chain Amino Acids
	D-Aspartic Acid
	Ecdysteroids
	Ephedrine
	Gamma Oryzanol
	Glutamine
	Kaempferia parviflora
	Leucic Acid
	Leucine
	Marijuana
	N-Acetylcysteine
	Nitrate
	Pyruvate
	Rhodiola Rosea
	Tribulus terrestris
	Vitamin D
	Yohimbine
	Eurycoma Longifolia Jack
	Vitamin C

All comparative evidence is now gathered in our ​A-to-Z Supplement Reference.

The evidence for each separate supplement is still freely available ​here.

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