Library.

“After proteases finish digesting food in the duodenum, they move with chyme into the mid and distal small intestine and begin digesting themselves and other enzymes into amino acids.”

The evidence supports that pancreatic proteases continue moving with chyme beyond the duodenum and may be degraded during transit. But the claim misstates both timing and mechanism: protein digestion is not simply finished in the duodenum, and free amino acids are produced mainly through brush-border and intracellular peptidases, not primarily by proteases digesting themselves and other enzymes.

“Under normal conditions, only a very small fraction of dietary amino acids in the small-intestinal lumen are diverted by other substances or are consumed by colonic bacteria before being absorbed, so amino-acid loss is very low.”

Most dietary amino acids are absorbed in the small intestine under normal, healthy conditions, so losses before absorption are generally low. Human studies and reviews commonly report ileal amino-acid digestibility above 90%, often above 95%. The wording is somewhat broad because digestibility differs by protein source and some proteinaceous material still reaches the colon, but that does not overturn the main conclusion for typical diets.

“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 improves brain fog in humans.”

Creatine may help some cognitive functions linked to what people call brain fog, but the evidence does not directly show that it generally improves “brain fog” in humans. Most studies measured objective cognitive tasks, not the symptom itself, and positive effects are most apparent in specific settings such as sleep deprivation, older adults, or other higher-demand conditions. The broad, unqualified wording goes beyond the evidence.

“Creatine supplementation increases the body's ability to regenerate methyl groups, thereby supporting methylation processes.”

Evidence shows creatine supplementation lowers the body’s need to use methyl groups for creatine synthesis, leaving more S-adenosyl-methionine available. No study demonstrates that it boosts the enzymes or pathways that regenerate methyl groups. The claim’s wording shifts from “spares methyl groups” (supported) to “increases regeneration ability” (unsupported), so the assertion is directionally related but overstated.