The pharmacological inhibition of fatty acid synthesis using TOFA for acetyl-CoA carboxylase (ACC) and C75 for fatty acid synthase (FAS) was successfully exploited to target glioblastoma multiforme (GBM) metabolism. Despite the minimal impact on normal human astrocytes’ viability, C75 and TOFA had significant deleterious effects on GBM expressed p75NTR, the neurotrophin receptor that regulates GBM invasion, growth and apoptosis. In addition to identifying a “two-way” relationship with the fatty acid synthesis pathway, a key role of p75NTR in the upregulation of many important pathways in GBM, including pentose phosphate pathway, mitochondrial anaplerosis, and glutaminolysis opens the windows for the developments of more drugs targeting GBM’s invasion metabolically. C75 treatment increased the carbon flux from glycogenolysis to fatty acid synthesis. Unexpectedly, the connection between ACC inhibition by TOFA and the upregulation of glutaminolysis in GBM provide advantages for further investigation on drugs targeting both fatty acid synthesis and glutaminolysis.