In human and veterinary drugs, Orion's customers in Finland include doctors, hospitals and clinics, pharmacies and their personnel as well as consumers. In other countries, Orion's customers typically include specialists of narrower medical fields, purchasing organisations of hospitals, and pharmacies.

Customer work with doctors is interactive and is characterised by supply of complementary educational information on drugs and their approval-based applicability. In its communications concerning medicinal products Orion adheres to the strict ethical guidelines and procedures for marketing and sales in the pharmaceuticals business.

Orion's customers also include other pharmaceutical companies for which Orion acts as a contract manufacturer or  which buy  active pharmaceutical ingredients or contract research and manufacturing services from Fermion.

Customers for diagnostic products include hospitals, health centres, laboratories, clinics, other pharmaceutical companies and food, process and mechanical engineering industries. Also some other diagnostics companies are Orion's customers,  Orion Diagnostica serving as a contract manufacturer of diagnostic products.