Alterations in signalling via muscarinic receptors play an important role in a variety of neurological, psychiatric and internal diseases, e.g. Alzheimer's disease, schizophrenia, asthma and syndrome of overactive bladder. Muscarinic receptors contribute to the development of addiction and modulate analgesia, immunity, thermoregulation, and other processes. Muscarinic receptors are thus an important but difficult pharmacotherapeutic target. The lecture will give an overview of 25 years of research of unique prototypical functionally selective agonist xanomeline.