About active and inactive medicine ingredients

Learn about what is, and what is not an active ingredient in prescription medicines.

What active ingredients are

Active ingredients are the chemical compounds in medicines that have an effect on the body. Essentially, they are the ingredients within your medicine that make the medicine work. A ‘brand name’ is the name given to a medicine by the company that makes it. 

There are many medicines that have the same active ingredients, but are made by different companies and have different brand names.

Prescribing and dispensing medicines by their active ingredient(s) means these ingredients are easier to identify on prescriptions and medicine labels. 

What inactive ingredients are

As well as the active ingredient, the medicine you take may have other ingredients. These are known as ‘inactive’ ingredients, or excipients. Medicine manufacturers may need to add other things when they make the medicine to:

  • fill out the product dose if the amount of active ingredient is very small
  • keep the active ingredient from changing, so it works for longer
  • help your body to better absorb the active ingredient
  • bind or hold tablets and other dose forms together
  • change the taste to make it easier to take or give (such as for young children)
  • coat the tablet or capsule to make it easier to swallow.

Some examples of ‘inactive’ ingredients are things like lactose, gluten, sugar, preservatives and dyes. For most people, these inactive ingredients won’t affect their choice of medicine.

However, some people may not be able to take certain ingredients due to requirements of their faith or health (such as allergies). 

Talk to your health professional to help you choose a brand that is best suited to your health needs.

Know what’s in your medicines

Knowing what the active ingredient is in a medicine is an important part of being safe when you take your medicines. 

For most situations, it is best practice to prescribe medicines using the active ingredient name. Active ingredient prescribing can reduce the risk of medication errors occurring. It will also make it easier for you to talk to your health professional about your choices for different medicines that have the same active ingredient, including whether there is a cheaper option available. 

Listing by active ingredients on your prescription and medicine labels will make it easier for you to check:

  • you are not taking the same active ingredient in other medicines. This will lower your chance of taking more than one medicine with that active ingredient by mistake.
  • you are not taking something you have had an adverse reaction to or may be allergic to 
  • the medicine is safe to take with your other medicines
  • brands containing the same active ingredient when you visit other countries.
Date last updated:

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