| Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase Deficiency (Fatty Acid Elongation in Mitochondria) |  | Disease | NADH / Palmitic Acid |
| Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase Deficiency (LCHAD) |  | Disease | NADH / Palmitic Acid |
| Long-term potentiation |  | Physiological | Glutamic acid / Calcium |
| Lonoctocog Alfa Action Pathway |  | Drug Action | Calcium / Lonoctocog alfa |
| Loperamide Action Pathway |  | Drug Action | ATP / Loperamide / Calcium / Magnesium cation / Cyclic adenosine monophosphate / Acetylcholine / Pyrophosphoric acid |
| Loperamide Metabolism |  | Metabolic | Loperamide / Mesoheme |
| Lopinavir Action Pathway |  | Drug Action | Magnesium cation / Lopinavir |
| Loratadine H1 Antihistamine Smooth Muscle Relaxation Action Pathway |  | Drug Action | Loratadine / Calcium / Magnesium cation |
| Loratadine H1-Antihistamine Action |  | Drug Action | Loratadine / Calcium |
| Loratadine H1-Antihistamine Blood Vessel Constriction Action Pathway |  | Drug Action | Arginine / Citrulline / Sapropterin / Nitric Oxide / Loratadine / Calcium / Magnesium cation / Mesoheme / Flavin adenine dinucleotide / Flavin mononucleotide |
| Loratadine H1-Antihistamine Immune Response Action Pathway |  | Drug Action | Doxylamine / Calcium |
| Lorazepam Action Pathway |  | Drug Action | Pyridoxal phosphate / Glutamic acid / ATP / Lorazepam / Calcium / Magnesium cation / Cyclic adenosine monophosphate / gamma-Aminobutyric acid / Pyrophosphoric acid |
| Lormetazepam Action Pathway |  | Drug Action | Pyridoxal phosphate / Glutamic acid / ATP / Calcium / Magnesium cation / Cyclic adenosine monophosphate / gamma-Aminobutyric acid / Pyrophosphoric acid |
| Lornoxicam Action Pathway |  | Drug Action | Glutamic acid / Glutathione / Dinoprostone / Calcium / Magnesium cation / Zinc / Prostaglandin D2 / Mesoheme / Prostaglandin G2 / Arachidonic Acid / Lornoxicam |
| Lornoxicam NSAID Action Pathway |  | Drug Action | Glutathione / Dinoprostone / Calcium / Mesoheme / Prostaglandin G2 / Arachidonic Acid / Lornoxicam |
| Lorpiprazole Serotonin antagonist Action Pathway |  | Drug Action | Pyridoxal phosphate / Tryptophan / Sapropterin / Calcium / Iron / Oxitriptan / Lorpiprazole |
| Losartan Action Pathway |  | Drug Action | Losartan / Potassium cation / Zinc |
| Losartan Angiotensin blocker Action Pathway |  | Drug Action | Glutamic acid / Losartan / Zinc |
| Loteprednol etabonate Action Pathway |  | Drug Action | Glutathione / Dinoprostone / Calcium / Prostaglandin D2 / Mesoheme / Prostaglandin G2 / Arachidonic Acid / Loteprednol etabonate |
| Lovastatin Action Pathway |  | Drug Action | Cholecalciferol / ATP / Lovastatin / Magnesium cation / Iron / Dimethylallyl Diphosphate / Formic acid / Geranyl Diphosphate / Mesoheme / Flavin adenine dinucleotide / Palmitic Acid / Pyrophosphoric acid / Cholesterol / ISOPENTENYL PYROPHOSPHATE / Farnesyl diphosphate |
| Lovastatin Action Pathway (New) |  | Drug Action | Lovastatin / Calcium / Zinc / Cholesterol |
| Lovastatin Predicted Metabolism Pathway |  | Metabolic | Lovastatin / Mesoheme |
| Loxapine Dopamine Antagonist Action Pathway |  | Drug Action | Pyridoxal phosphate / Tyrosine / Sapropterin / Loxapine / Dopamine / Levodopa / Calcium / Iron |
| Loxapine Predicted Metabolism Pathway |  | Metabolic | Loxapine / Mesoheme |
| Loxoprofen Action Pathway |  | Drug Action | Glutathione / Dinoprostone / Calcium / Mesoheme / Prostaglandin G2 / Arachidonic Acid |