The Science of Herbs & How They Work

Pharmacognosy and Pharmacokinetics of Herbs

When I first began my herbal medicine journey, I was much like everyone else. I began doing research online, googling things like “herbs for headaches”, and thinking I knew a lot about herbs simply from my own online research. When you try to implement these findings into your daily life, however, you may find that just knowing that one herb can be used for a certain symptom, yet you don’t understand why it works, causes more confusion than healing. When we don’t understand how herbs and their botanical compounds work, we do ourselves a disservice. 

There are many herbs that can support one symptom that your body is having, but which one is the best? How exactly does the chemical makeup of herbs interact with the human body? What are the properties of these plant chemicals? This is where we start learning about pharmacognosy, and it is an integral part of holistic learning.

The American Society of Pharmacognosy defines pharmacognosy as “the study of the physical, chemical, biochemical, and biological properties of drugs, drug substances, or potential drugs, or potential drug substances of natural origin, as well as the search for new drugs from natural sources.”

Broken down into an easier to understand definition—pharmacognosy defines and teaches us about the physical, chemical, and other properties and actions of herbs and plants, and how they work. Chemical groups and families within herb substances have actions that can be generalized. There are some botanical components you should know about when it comes to the chemical actions of herbs and how they work with the human body. Knowing how herbs work will help you choose the best options that are needed for an ailment, disease, or symptom. It especially helps you when studying a new plant in the wild. 

While generalized definitions of these chemicals and actions make it easy, we should never confine these herbs only to these generalized actions. As you dive further into your herbal education in this book, you'll understand more confidently how they work together, not just independently, as well.

Once you feel confident in knowing the pharmacognosy aspect of herbs, from there you may be better able to understand pharmacokinetics. Pharmacokinetics (sometimes abbreviated PK) is a branch of pharmacology dedicated to determining the fate of substances administered to a living organism. It is the branch of pharmacology concerned with the movement of drugs or substances within the body—absorption, distribution, metabolism, and excretion. Essentially, how does this herb or remedy work in the body most efficiently, and what does the body do with the herb or remedy once it has been distributed and metabolised? Are all herbs excreted immediately, or are some reabsorbed? Let’s find out. 

Let’s pull pharmacognosy and pharmacokinetics together. First, let's look at the chemical compounds of herbs—pharmacognosy.