| G | Generic |
| G-CSF | Granulocyte Colony Stimulating Factor |
| G6PD | Glucose-6-Phosphate Dehydrogenase |
| GA Derma. | Granuloma Annulare |
| GA Eye | geographic atrophy |
| GAA | Glucosidase Acid Alpha |
| GAAP | Greater Access to Affordable Pharmaceuticals act |
| GABA | Gamma Amino Butyric Acid |
| GACI | Generalized Arterial Calcification of Infancy |
| GAD | Glutamic Acid Decarboxylase |
| GAD | General Anxiety Disorders |
| GAD | Gastro Adhesive Dosage |
| GAG | Glycos Amino Glycan |
| Gal | Galactose |
| GaN | Gallium Nitride |
| GAPI | Genox Antioxidant Profile Index |
| GAX | Growth Arrest Homebox (Gene) |
| GBCA | gadolinium-based contrast agent |
| GBF | Gesellschaft für Biotechnologische Forschung (Germany) |
| GBM | Glio Blastoma Multiforme |
| GBP | Glucose Binding Protein |
| GBS | Group B Streptococcus |
| GC | Gas Chromatography |
| GC | Gastric Cancer |
| GC-C | Guanylate Cyclase-C |
| GC-O | GC Olfactometry |
| GCP | Granulocyte Chemotactic Protein |
| GCS | Gluco Cortico Steroid |
| GCSF | Granulocyte Colony-Stimulating Factor |
| GCTB | Giant Cell Tumor of the Bone |
| GD1 | Gaucher Disease type 1 |
| GDE | Gas Diffusion Electrodes |
| GDF | Growth Differentiation Factor |
| GDI | Gasoline Direct Injection |
| GDM | gestational diabetes mellitus |
| GDNF | Glial cell line-Derived Neurotrophic Factor |
| GE | Genetically Engineered |
| GEJ | Gastro Esophageal Junction |
| GEP | GastroEnteroPancreatic |
| GERD | Gastro Esophageal Reflux Disorder |
| GFAP | Glial Fibrillary Acidic Protein |
| GFD | Gallons per square foot per day |
| GFD | Gallons per square Foot of membrane per Day |
| GFP | Green Fluorescent Protein |
| GGF | Glial Growth Factor |
| GGT | Gamma Glutamyl Transpeptidase |
| GH | Growth Hormone |
| GHD | Growth Hormone Deficiency (in Children) |
| GHG | Green House Gases |
| GHIS | Growth Hormone Insensitivity Syndrome |
| GHRF | Growth Hormone Releasing Factor |
| GHRH | Growth Hormone Releasing Hormone |
| GHTP | Glucan H Type Phosphorylase |
| GI | Gastro Intestinal |
| GILT | Glycosylation Independent Lysosomal Targeting |
| GIOP | Glucocorticoid Induced Osteo Porosis |
| GIP | Gastric Inhibitory Polypeptide |
| GIP | Glucose-dependent Insulinotropic Peptide |
| GIP-R | Glucose-dependent Insulinotropic Peptide-Receptor |
| GIPSA | Grain Inspection, Packers and Stockyards Administration |
| GIST | Gastro Intestinal Stromal Tumor |
| GIT | Gastro Intestinal Tract |
| GITS | Gastro-Intestinal Therapeutic System |
| GK | Gluco Kinase |
| GKA | Gluco Kinase Activator |
| GKRP | Gluco Kinase Regulatory Protein |
| GLA | Gamma Linolenic Acid |
| Glc | Glucose |
| Glc UA | Gluc Uronic Acid |
| GLDH | Glutamate De Hydrogenase |
| GLP | Glucagon Like Peptide |
| GLTP | Glucan L Type Phosphorylase |
| GLU | L-GLUtamyl |
| GLUT | GLUcose Transporter |
| GM | Granulocyte Macrophage |
| GM | Genetically Modified |
| GM-CSF | Granulocyte Macrophage Colony Stimulating Factor |
| GMA | Glycidyl Meth Acrylate |
| GMBS | N-(Gamma-Maleimido Butyryloxy Succinimide |
| GMBT | Gastric Motility Breath Test |
| gMG | generalized Myasthemia Gravis |
| GMO | Genetically Modified Organism |
| GMP | Good Manufacturing Practice (Biopharma., Pharma.) |
| GMP | Glyco Macro Peptides |
| GMP | Guanosine Mono Phosphate |
| GMR | Giant Magneto Resistance |
| GMS | Glycerol Mono Stearate |
| GnRH | Gonadotrophi n-Releasing Hormone receptor |
| GOSPI | Genox Oxidative Stress Profile Index |
| GP | Glyco Protein |
| GP | General Purpose |
| GPC | Gel Permeation Chromatography |
| GPCR | G Protein Coupled Receptor |
| GPI | Glycosyl Phosphatidyl Inositol |
| GPO | group purchasing organization |
| GPP | Generalized Pustular Psoriasis |
| GPRC5D | G Protein-coupled Receptor Class C group 5 member D |
| GPS | Global Positioning System |
| GPTS | 3-Glycidyloxy Propyl Trimethoxy Silane |
| GPTSI | 3-Glycidyloxy Propyl Trimethoxy SI lane |
| GPU | Graphics Processing Unit |
| GPX | Glutathione PeroXidase |
| GR | GRanulated |
| GR | Glucocorticoid Receptor |
| GRAB | Genetically Recombinant Anti Body |
| GRAS | Generally Recognized As Safe |
| GRAS | Generally Regarded As Safe |
| GS | Glutamine Synthase |
| GSH | Glutathione |
| GSK | Glycogen Synthase Kinase |
| GSK | Glaxo Smith Kline |
| GSM | Global Systems for Mobile communications |
| GSNO | Gluthathione S NO (Nitroso) |
| GSPE | Grape Seed Proanthocyanidin Extract |
| GSSM | Gene Site Saturation Mutagenesis |
| GST | Glutathione S Transferase |
| GST | Germanium Sb Telluride |
| GTAC | Gene Therapy Advisory Committee (UK) |
| GTAC | Global Technology Assessment Center |
| GTI | Geno Toxic Impurities |
| GTL | Gas To Liquid (Natural gas to liquid hydrocarbon conversion) |
| GTR | Guided Tissue Regeneration |
| GTT | Glucose Tolerance Test |
| GVG | Gamma Vinyl GABA |
| GVHD | Graft Versus Host Disease |
| GWP | Global Warming Potential |
| GYK-DTPA | glycyl-tyrosyl-(N,-diethylenetriaminepentaacetic acid)-lysine hydrochloride |