Yes. The placebo effect is a real, measurable psychobiological response in which expectations, care rituals, and brain–body pathways can improve symptoms even when the treatment itself is inert. Research links placebos to changes such as endorphin and dopamine release and activity in brain regions involved in pain and emotion; they are most often helpful for brain-modulated symptoms like pain, stress-related insomnia, and some treatment side effects, not for curing disease or changing lab markers such as cholesterol.
Source: Harvard Health — The power of the placebo effect