2 verifications about S-Adenosylmethionine S-Adenosylmethionine ×
“Creatine supplementation reduces S-adenosylmethionine (SAMe) demand by decreasing endogenous creatine synthesis.”
Available evidence supports this mechanism. Creatine supplementation suppresses endogenous creatine synthesis, and that synthesis normally uses SAMe to methylate guanidinoacetate into creatine, so the pathway’s SAMe demand falls. Unchanged blood SAM, SAH, or homocysteine in some trials does not negate this, because those markers do not directly measure pathway flux.
“Creatine supplementation reduces demand for S-adenosylmethionine (SAMe), thereby increasing SAMe availability for neurotransmitter production.”
Creatine likely reduces the body’s need to synthesize as much creatine, lowering one major use of SAMe-derived methyl groups. But the evidence does not show that this spared capacity is actually redirected into neurotransmitter production. Human studies on methylation proxies are mixed, and reviews of creatine’s brain effects describe the neurotransmitter pathway as indirect or unproven.