Pharmacology is the study of the action of drugs on a biologic system. It incorporates components of medicine and biology, and how they interact with each other.

Drugs can refer to many different substances, and are defined as any substance (man-made, naturally occurring or endogenous molecules) that exerts an effect on a cell, tissue, or organ within the body.

Pharmacology deals with the origin of drugs, their characteristics, and their effects, such as biologic, chemical or therapeutic, on a living system.

Pharmacology is distinct from pharmacy. Pharmacology refers to the science of the discovery and characterization of substances that have an effect on the body.

On the other hand, pharmacy refers to the health services that use the concepts of pharmacology to improve health outcomes in a clinical setting.

Medical pharmacology laboratory. Image Copyright: Zarya Maxim Alexandrovich / Shutterstock


Traditionally, the actions of pharmaceutical substances – usually from natural sources or plant extracts, such as morphine and quinine – were poorly understood and explained in general terms, without deep knowledge of their actions on the body.

Clinical pharmacology dates back to the Middle Ages, and William Withering (1741-1799) was one of the primary founders of this field of study. However, it was not until halfway through the 19th century that it progressed further as a scientific discipline. This was largely due to the advancements in biomedical science at that time.

Throughout the 19th and 20th century, the field of pharmacology as a biological science continued to develop and its discoveries began to be applied in a therapeutic setting.

Today, pharmacologists use a variety of techniques, including genetics, molecular biology and chemistry, to explain and manipulate the pharmacological action of substances for health purposes. This has helped to bring about great advances in the field of medicine over the past century.

It has brought in a deeper understanding of how medications can be effectively used to manage various health conditions and diseases.

Pharmacology Topics

Pharmacology is a broad field, and its study includes a number of different topics. These include:

Pharmacodynamics and Pharmacokinetics

Pharmacodynamics and pharmacokinetics are the two principal areas of pharmacology. Pharmacodynamics focuses on the effect that a drug can exert on the biology of the body. Pharmacokinetics focuses rather on how the body affects the drug, in terms of its absorption, metabolism, distribution and elimination.

Pharmacodynamics is based on studying how pharmaceutical substances affect the receptors in the body, and on how these effects can be beneficial for certain purposes.

Pharmacokinetics studies how the body reacts when pharmaceutical substances are introduced into the bodily systems. This is split up into four main topics: absorption of the drug, distribution around the body, metabolism into other substances and excretion from the body (referred to as ADME).


There are many different sub-disciplines or specializations under the umbrella of pharmacology. These include:

A pharmacologist may specialize in any one of these sub-disciplines to conduct deeper research into a specific area of pharmacology.


Further Reading

Written by

Yolanda Smith

Yolanda graduated with a Bachelor of Pharmacy at the University of South Australia and has experience working in both Australia and Italy. She is passionate about how medicine, diet and lifestyle affect our health and enjoys helping people understand this. In her spare time she loves to explore the world and learn about new cultures and languages.

Last updated Dec 30, 2022


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