Off-label drugs: what are they?

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Gina Allegretti, MD 

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Gina Allegretti, MD 

last updated: Oct 13, 2021

4 min read

It can be confusing to hear you’re getting an off-label medication. When a healthcare provider prescribes a medication or treatment off-label, it doesn’t mean they’re going rogue. Licensed clinicians are permitted to use their professional judgment to prescribe drugs off-label if they feel it's the best treatment for patients. It might sound like something is prescribed “under the table,” but off-label prescriptions are actually quite common. In some cases, they’re even the best treatment option.


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What does off-label mean?

Before we dig in, let’s define what we mean by off-label. Before prescription drugs are introduced to the general public, they’re tested in clinical trials to make sure that they’re safe. These trials also test to make sure the medication is effective at treating the condition it's being evaluated to treat. Researchers collect scientific evidence and set up guidelines for each new drug, and then the U.S. Food and Drug Administration (FDA) evaluates the data. It’s a complex process that can take years, but once a drug is approved for a given use, it’s considered to be on-label.

During the study phase, researchers may observe a medication is helpful for more than just the intended condition. Although it’s not what the medication was initially approved for, your provider may prescribe it anyway. For example, the drug prazosin is approved to treat high blood pressure but has also been found to be effective for PTSD-related nightmares. This is called off-label prescribing (Koola, 2014). 

The medication terbutaline is most typically prescribed to treat asthma, but clinicians have found it's also effective at stopping uterine contractions during labor. And while the FDA has never granted drug approval for this use, it’s standard practice to use it to stop premature labor.

If you’re given medication off-label, it doesn’t mean it’s illegal, nor are you becoming part of some unknown experiment. There are plenty of good reasons for prescribing off-label that we’ll get into below.

Why use an off-label drug? 

There are so many medications available for seemingly every condition––so why would a healthcare provider prescribe something off-label? Here are some of the most common reasons.  

No known treatment for a disease

New diseases need new solutions, but it takes time to develop and test them. For example, in 2019 COVID-19 was a brand new disease. No previous trials identified effective medications or guidelines on how to manage severe cases. On top of that, it would likely take months or even years to test and get approval for new treatments.

Because of this, healthcare experts turned to other treatments already FDA-approved for treating other similar viruses. Since the therapies were already tested and deemed safe, they made good candidates as off-label drugs to treat COVID (WHO, 2020). Off-label drug prescribing is common when it comes to the treatment of rare diseases for the same reasons. 

When a study can’t be done to evaluate the effectiveness of a medication 

There is much more scientific evidence available about medications for adults than children. 

One reason for that is that it can be difficult to enroll children in clinical trials from an ethical perspective. Consent is an important part of participating in clinical studies and it’s not something children can provide. Our biology is also different at different stages of life (especially during childhood), making the establishment of pediatric guidelines problematic. For these reasons, medications with labeled uses in adults are often used off-label to treat the same conditions in children.

For example, the drug morphine is FDA-approved for pain relief and often administered after surgery. Children also frequently receive this medication for pain, but in kids, the use is typically considered to be off-label since it hasn’t been approved for this age group (Shah, 2007).  

In the case of terbutaline mentioned previously, there’s no ethical way to do a study comparing the effectiveness of a drug that stops preterm labor to a placebo since an ineffective medication might risk the life of the baby, mother, or both. For that reason, healthcare providers will continue to use the drug off-label and it won’t receive FDA approval despite plenty of research demonstrating its effectiveness. 

When other approved treatment methods have failed

Off-label prescribing is very common in cancer treatment. Sometimes people are initially treated with an FDA-approved medication. However, not every medication works for everyone. When this happens, a healthcare provider may use a different medication off-label. 

Off-label prescribing is used in up to one-third of people with metastatic cancer ( cancer that has spread to other areas of the body) and people receiving palliative care, which is care meant to make them more comfortable but will not cure their disease (Saiyed, 2017). One small study found that 34% of cancer patients who received off-label treatments reported clinical benefits (van der Velden, 2019). Cancer is actually many different diseases, and each form has different symptoms and characteristics, so the results of these off-label cancer treatments can vary from person to person. 

Similar treatments have been approved

Off-label prescribing is common in the treatment of mental health conditions. Many mental healthcare professionals prescribe off-label antipsychotic, antidepressant, and attention deficit hyperactivity disorder (ADHD) drugs, though the off-label drugs they prescribe are often in the same drug class as the FDA-approved ones.  

You might think swapping out one drug for another isn’t the best idea, but medications in the same class frequently have similar or even identical effects on the body. These drugs also share similar side effects, so healthcare providers are often comfortable substituting on-label drugs with off-label ones. For example, the selective serotonin reuptake inhibitor (SSRI) escitalopram (brand name Lexapro) is FDA-approved to treat anxiety but is also used off-label to treat eating disorders and obsessive-compulsive disorder (OCD). 

Another drug in this class is citalopram (also known as Celexa), which is often used off-label for anxiety even though it’s not labeled for that purpose (Vijay, 2018). Providers can also take the liberty of choosing an off-label equivalent if it is covered by insurance when the on-label drug isn’t. 

What are the disadvantages of prescribing off-label? 

Proper prescribing of off-label medication relies on the expertise of an experienced healthcare provider who is familiar with the medication and the condition being treated and is aware of any potential complications or interactions that might arise. 

Sometimes, off-label use opens doors for new uses and indications for existing medications. But because the FDA doesn’t regulate this process, healthcare providers must use their best judgment in advising patients on what to take. 

If you’ve been prescribed a medication off-label, you can ask your provider or pharmacist about the reason behind choosing the treatment to better understand your health.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

October 13, 2021

Written by

Gina Allegretti, MD

Fact checked by

Yael Cooperman, MD

About the medical reviewer

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.