Positron Emission Tomography Image Guided Drug Delivery: Current Status and Future Perspectives Molecular Pharmaceutics Follow for more info on how to optimize your health. Semax and Dihexa are not interchangeable and treating them like they are is where most people get confused. Semax is about Drug Absorption and Bioavailability Basicmedical Key Oral bioavailability of ivacaftor DDDT Dove Medical Press Follow for more info on how to optimize your health. Dihexa gets misunderstood because people expect it to feel like stimulation. That's not what it's about. This is about adaptation, not activation.