Taking a generic drug is not like buying a store-brand soap. With soap, you might notice a difference. It may smell different. You may need to use more than the brand-name product. That is not true with generic drugs. Generic drugs are like brand-name drugs.

When companies make a brand-name drug, they get a patent. A patent stops other drug companies from making and selling the same drug before the patent runs out. When the patent on a brand-name drug expires, other drug companies can make a generic version. 

After getting approval from the U.S. Food and Drug Administration (FDA),  the generic drug is made and sold under the active ingredient’s name.

Check out these common myths and facts about generic drugs:

What Is Bioequivalence?

Generics don’t have to repeat the long clinical studies used to make the brand-name drug. The safety and value of the brand-name product has already been proven with research and many years of patient use.
Instead, companies that want to make a generic must show the FDA that it is a “bioequivalent” to the brand drug. That means:

• It is made in the same way.
• It is made with the same ingredients.
• It acts the same in the body.

How It Works

The FDA considers several factors before it allows a company to make and sell a generic drug.

1. There must be an FDA-approved brand-name drug the generic can copy.
2. The generic must have the same ingredients at the same strength.
3. It must come in the same form, like a tablet or liquid. It must be taken the same way — swallowed or given as a shot.
4. The drug company must show that the generic is bioequivalent to the brand-name.
5. The generic's labeling must be the same.
6. The drug company must prove the generic's chemistry, show how it’s made and uphold quality controls.
7. Ingredients and the finished product must meet purity standards.
8. The generic must be stable. It can’t change over time or in normal conditions.
9. The company must follow federal rules for good manufacturing. It must allow FDA inspections.
10. Before the FDA approves a generic drug, it often checks the manufacturing site to make sure the company can meet its promises and produce a steady supply.

Now that you know the care and safety that goes into making generic drugs, you can take yours with peace of mind.

Source: A Primer on Generic Drugs and Bioequivalence,  U.S. Food & Drug Administration, 2021.

Originally published 5/11/2016; Revised 2021, 2022