The FDA drug approval process has a lot of steps, and for a good reason—it’s designed to protect public health. The Food and Drug Administration (FDA) oversees the testing and marketing of all human drugs in the United States. Before a drug can hit your medicine cabinet, the FDA must evaluate new drugs’ benefits and risks.

The FDA approval process timeline can take years (with some exceptions, which we’ll discuss later). During that time, drugs are researched, tested, and reviewed multiple times to provide doctors and patients with the information they need to use new medications safely.

Here’s a high-level overview of the FDA drug approval process in the United States.

What Is the FDA Drug Approval Process?

The drug approval process begins with the drug manufacturer or sponsor. A “sponsor” is the person or entity responsible for marketing a new drug. They work with the FDA’s Center for Drug Evaluation and Research (CDER)to submit a drug for review.

However, getting to that step takes a lot of time, research, and paperwork. Once a drug has been developed and screened for toxicity in animal trials, it’s ready for clinical trials: research studies that test how well a medicine works in people.

FDA clinical trials consist of four phases: 1

  • Phase one: An initial trial to determine drug safety.
  • Phase two: A slightly larger trial that is designed to determine drug effectiveness.
  • Phase three: Large-scale clinical trial consisting of thousands of participants.
  • Phase four: Monitoring stage to identify any safety concerns after approval.

This process only applies to prescription drugs. The process is different for over-the-counter, medications, and there’s no formal approval for dietary and herbal supplements.2

The Four Phases of Drug Approval

The FDA phases are designed to help ensure that a new medication is safe and does what it claims to do.

Phase One

During the development process, a drug is tested in animal trials to gather basic information on safety and efficacy. Once it enters phase one, the drug is officially tested in humans.

Phase one trials are generally pretty small, consisting of 20 to 80 participants. In this phase, the goal is to determine side effects and how long it takes the body to break down the drug.

Phase Two

This phase determines the drug’s effectiveness in people with a particular disease or condition. Phase Two consists of hundreds of participants. These trials tend to compare the drug against another treatment, such as a placebo or a different drug.

In 2021, Compass Pathways completed phase two clinical trials for COMP360, a psilocybin formulation for use in people with treatment-resistant depression.

Phase Three

Phase three is a large-scale controlled trial consisting of thousands of patients. This phase studies the drug in various populations, with different dosages and drug combinations, to gather more info about safety and effectiveness.

The Multidisciplinary Association for Psychedelic Studies (MAPS) is currently conducting phase three trials to investigate MDMA-assisted psychotherapy for PTSD.

MDMA, which has breakthrough therapy status, is expected to be the first FDA-approved psychedelics medication. Drugs with breakthrough status are eligible for accelerated approval and priority FDA review, among other features.3

Phase Four

Unlike the other phases, phase four begins after a drug is FDA-approved.

Although clinical trials can provide valuable evidence, it’s impossible to predict all of a drug’s effects. So, the FDA has systems in place to monitor the safety of drugs once they hit the market.

For example, the FDA requires that sponsors submit periodic safety updates. Additionally, physicians and consumers can report adverse reactions through the FDA’s MedWatch system.

Risks are added to the drug’s labeling and public education when identified. In some cases, the FDA will limit the use of a drug. And in rare cases, the drug is pulled from the market.

What Is a New Drug Application (NDA)?

A drug manufacturer or sponsor submits a new drug application (NDA) to formally ask the FDA to approve a drug for marketing in the United States. The NDA includes all animal and human research, manufacturing data, and information about how the drug behaves in the body.

After receiving an NDA, the FDA has 60 days to file the application for review. Then, an FDA review team evaluates the research and makes the final call. The standard review process takes about 10 months.

Important Facts About FDA Drug Approval

What happens after the final drug approval?

Once a drug is FDA-approved, it can be sold and marketed in the United States. Because clinical trials can’t predict all of a drug’s potential adverse effects, the FDA continues to monitor drug safety after it hits the market.

You can search for FDA-approved drugs through the Drugs@FDA website.

Who is on the FDA advisory board?

An advisory committee is a group of outside experts who provide independent opinions and recommendations as the FDA reviews a drug application. The exact people in a committee can vary; members are selected because of their expertise and knowledge.

Advisory committee members can include:

  • Scientific experts, such as researchers, medical faculty, and chemists
  • A consumer representative who represents the consumer perspective on issues and actions before the advisory committee
  • An industry representative who acts on behalf of the regulated industry at committee meetings
  • An FDA patient representative who provides critical advice to the agency

What are accelerated approvals?

Accelerated approval allows a drug to be approved faster because it fills an unmet medical need. Rather than waiting for results from a clinical trial, the FDA can base the approval on a different measure of effectiveness, such as a blood test.

Accelerated approval doesn’t mean the research stops once the drug hits the market. Companies are required to continue studying the drug to confirm initial results. The FDA can withdraw the approval if the evidence doesn’t match up.

Does the FDA keep monitoring after approval?

Even after giving approval, the FDA continues to monitor drugs in case negative reactions occur that didn’t appear during clinical trials.

When are Emergency Use Authorizations (EUA) granted?

An emergency use authorization (EUA) speeds up the availability of drugs during a public health emergency. The EUA process is similar to full FDA approval, only faster. The drug manufacturer or sponsor still has to conduct research and clinical trials.

For example, the FDA granted EUAs to two COVID-19 vaccines to expedite their distribution to the public. Compared to the EUA, the full FDA approval requires more data about the drug maker’s processes and facilities, including inspections of manufacturing plants.

Final Thoughts

The FDA drug approval process applies to any prescription drug intended to diagnose, cure, treat, or prevent disease. The FDA hasn’t formally approved any psychedelic drugs as of this writing.

For now, clinical trials are investigating the safety and efficacy of psychedelic medicines. These trials will provide important information to help ensure that people in the near future can use FDA-approved psychedelics safely.


  1. Development & Approval Process | Drugs | FDA. Accessed September 14, 2022.
  2. How are drugs approved for use in the United States? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development. Accessed September 14, 2022.
  3. Fast Track | FDA. Accessed September 14, 2022.