A deficiency in vitamin B12 can lead to fatigue, weakness, and even permanent nerve damage
doi:10.1021/jf052400h
The GlyNAC combination (glycine + NAC) showed multi-system improvements in a 16-week RCT in older adults, including corrected glutathione deficiency, reduced oxidative stress, improved mitochondrial function, and enhanced physical performance
In our study, the relative risk of symptomatic cholelithiasis was 1.6, 1.4, and 0.9 in liraglutide, Semaglutide, and dulaglutide versus control group, with the number needed to harm of 3.14, 5.56, and 16.6, respectively
With caffeine, its usually due to having too much caffeine, which is considered anything over 400 mg per day (though amounts can vary depending on individual factors)