Chemical substances that have a calming effect are known as?

Chemical substances that have a calming effect are known as anxiolytics or sedatives. These substances can help reduce anxiety, promote relaxation, and induce sleep. Common examples include benzodiazepines, certain antidepressants, and natural substances like valerian root. They work by affecting neurotransmitter systems in the brain, particularly those involving gamma-aminobutyric acid (GABA).