IV fluids bypass the digestive system and allow for full absorption of essential vitamins, nutrients, amino acids, and herbs administered directly into the bloodstream
What we do know is that adding protein to a mixed meal increases GLP-1, and a specific amino acid seems to increase GLP-1 the most (based on a rat study): phenylalanine
Aside from cytosolic amino acid sensors, intra-lysosomal amino acid sensing coincided with the identification of SLC38A9, a lysosomal transmembrane protein likely belonging to arginine transporters and an integral part of mTORC1 activation via Ragulator-RAG GTPases (Jung et al., 2015
By taking them together, you are providing the fuel (Vitamin D3) and the infrastructure (Glutathione) at the same time
Because it has a long half-life of about five days, the drug stays active in your system throughout the entire week regardless of whether you inject it in morning, afternoon, or evening