Off-label prescription drug use is legal and very common in the United States. You may have heard of this practice before. You may have even been prescribed a drug for off-label use, perhaps without knowing it. But like many people, you may not fully understand what off-label drug use means. Read on to learn about what off-label drug use is, why it occurs, and what to ask your doctor about it.

To help you understand what off-label use means, let’s start by explaining what FDA approval and drug labels are.

The FDA controls which drugs can be sold in the United States. Before a drug can be marketed and sold to treat a certain condition, the FDA has to approve it. When the FDA approves a drug, it works with the manufacturer to create a label for that drug. This drug label includes both the label on the drug package and a detailed report called the package insert. This report includes key information, such as:

  • recommended dosage for the drug, or how much and how often the drug should be taken
  • drug route, or how the drug is taken, such as a tablet taken by mouth
  • age ranges of people that the drug is recommended to treat
  • side effects that the drug could cause

The label also includes details about warnings and other important usage information. Doctors use the label information to help them decide how to prescribe the drug.

Off-label drug use means that a drug that has been approved by the FDA for one purpose is used for a different purpose that has not been approved. The lack of approval is not because the FDA has refused to provide it. Rather, it’s because the FDA has not been asked to evaluate the drug for that particular purpose. That means that purpose is not included in the drug label, and the FDA doesn’t provide any guidance for that usage of the drug.

However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing, approval, and marketing of drugs. But they do not regulate how doctors use drugs to treat their patients. So, your doctor can prescribe a drug however they think is best for your care.

If your doctor decides to use a drug off-label, that means they’re prescribing the drug in one or more of the following ways.

For a condition that has not been reviewed or approved by the FDA

For instance, aripiprazole (Abilify) is approved to treat schizophrenia, but doctors sometimes prescribe it off-label to treat dementia.

In a dosage or by a route that has not been reviewed or approved by the FDA

For instance, long-acting morphine tablets are not approved for rectal use. However, they are sometimes given that way to hospice patients who can’t swallow tablets.

In a patient population that has not been reviewed or approved by the FDA

For instance, polyethylene glycol 3350 (Miralax) is not approved for use in children. However, your child’s doctor may decide to prescribe it for your child.

Another example of a drug commonly prescribed for off-label use is dexamethasone. It’s approved for many uses, such as treating allergic reactions and reducing inflammation or swelling. It’s not approved to prevent nausea from chemotherapy. Still, it’s been widely used off-label for that purpose for many years.

Some off-label uses work so well they’re used as a first-line treatment. This means they’re the main treatment used for a condition. One example is tricyclic antidepressants. These drugs are approved to treat depression. However, these drugs are also now a first-line treatment for neuropathic pain (a type of chronic nerve pain), even though the FDA has not approved this use.

Perhaps the main benefit of off-label drug use is that it provides access to a wider range of drugs. A doctor has more drug options for their patients this way than if they only prescribed drugs for approved uses. Increased drug access can benefit people with many conditions, from migraines to HIV.

Specific reasons why a doctor might use a drug off-label include:

New uses

Doctors and researchers may have found a new use for an older drug, but the maker of the drug has not requested FDA approval for that use.

Limited usage

A drug maker may not have requested FDA approval for use of the drug in a certain population, such as children.

Lack of appropriate approved choices

This may be the case in several situations. For example, approved drugs may not work to treat someone’s life-threatening condition. The person’s doctor may think that an off-label use of a drug offers a higher chance of benefit. In other cases, an approved drug may not be the best choice for a certain person. For instance, the drug may cause serious side effects or an allergic reaction for that person. As a result, the doctor may choose another drug that’s in the same class as the approved drug and use it off label for the same purpose.

Yes, studies show that it is very common in the United States. For one 2006 study, researchers reviewed off-label drug use by office-based doctors in 2001. The study results showed that 21 percent of prescriptions were for off-label uses. The study also showed that off-label use was even more common for certain types of drugs, such as drugs used to treat seizures.

Another study from 2008 showed that off-label use is much more common in cancer care than in other types of care. The study found that 81 percent of surveyed cancer doctors reported prescribing drugs off-label.

Off-label drug use is also more common for patient groups that are not often included in clinical trials. These groups include children, pregnant women, and psychiatric patients. These people are not often studied in clinical trials because they may have a higher risk of side effects than most other groups.

Because there are no FDA-approved instructions for prescribing drugs for off-label uses, doctors may do their own research on how best to use a drug off-label. For instance, they may consult with other doctors who have used the drug. Or they may follow any guidelines that are available. These guidelines may come from medical researchers who run their own clinical trials to test a drug for an off-label use. These researchers may publish their results in peer-reviewed medical journals. Also, some health organizations or professional societies may provide treatment guidelines for off-label use. Your doctor may follow any of these guidelines when prescribing a drug for off-label use.

They may or they may not. Your doctor may prescribe an off-label drug that works so well and is so commonly used that it has become an accepted method of treatment. As a result, your doctor may not see a reason to mention it. Your doctor is not required by law to tell you about any off-label drugs they prescribe for you.

In some cases, though, your doctor may think it’s important to discuss the off-label use of a drug. For instance, if you have a rare cancer that has only a few approved drug treatment options, you doctor may know of an off-label drug use that could help you. If there’s not much published research on that use, your doctor may want to talk to you about it. They may want you to know that there could be unknown risks of using the drug for that purpose.

The process starts with the drug manufacturer, not the FDA. If the maker of a drug wants the FDA to approve a drug for a new use, the maker must conduct new testing for that use. This testing can take years and be extremely costly. Also, the FDA must thoroughly review all of the testing results. In short, the drug approval process is lengthy and complex. Drug companies won’t always pursue FDA approval of a drug for a new use because of the hurdles.

If your doctor prescribes a drug for you for an off-label use, you should feel free to ask any questions you may have. You have a right to be involved in any decisions about your care. Examples of questions you may ask include:

  • Is this drug approved to treat my condition?
  • Why did you prescribe an off-label use of this drug?
  • Are there other approved drugs available that can do the same thing?
  • Does research support the use of this drug for this purpose?
  • Will my health insurance cover this drug for off-label use?
  • Do you know what side effects I may have from this drug?
  • Have you ever given this drug for this off-label purpose? If so, what kind of results did those people have?


What should I know about side effects from off-label drug use?

Anonymous patient


A 2015 study showed that in general, off-label drug use causes more adverse drug reactions (ADRs) than approved drug use. Most ADRs are mild effects, but some are serious. The study also found that if research supports the off-label use, that use likely has the same risk of ADRs as an approved use. Ask your doctor any questions you have about side effects from an off-label drug use. Be sure to ask if any research supports that use. If there’s been no research on a certain use, you may not know what side effects to expect.

Sue Bliss, RPh, MBA
Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.