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  1. Frequently Asked Questions on Popular Topics

Generic Drugs: Questions & Answers

Spanish Language version - Medicamentos Genéricos: Preguntas y Respuestas (PDF - 213 KB)Generic Brands Same Quality and Performance

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What are generic drugs?

A generic drug is a medication created to be the same as an already marketed brand-name drug in dosage form, safety, strength, route of administration, quality, performance characteristics, and intended use. These similarities help to demonstrate bioequivalence, which means that a generic medicine works in the same way and provides the same clinical benefit as the brand-name medicine. In other words, you can take a generic medicine as an equal substitute for its brand-name counterpart.

Additional Resource

Generic Drug Facts
At-a-glance information on generic medicines, including why they may look different or cost less than brand-name medicines.

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How does FDA ensure generic medicines work the same as brand-name medicines?

Any generic medicine must perform the same in the body as the brand-name medicine. It must be the same as a brand-name medicine in dosage,  form and route of administration, safety, effectiveness, strength, and labeling (with certain limited exceptions).  It must also meet the same high standards of quality and manufacturing as the brand-name product, and it must be and quality, taken and used in the same way as well. This standard applies to all generic medicines.

Generic medicines use the same active ingredients as brand-name medicines and work the same way, so they have the same risks and benefits as the brand-name medicines. The FDA Generic Drugs Program conducts a rigorous review to ensure generic medicines meet these standards, in addition to conducting inspections of manufacturing plants and monitoring drug safety after the generic medicine has been approved and brought to market.

A generic drug may have certain minor differences from the brand-name product, such as different inactive ingredients. 

It is important to note that there will always be a slight, but not medically significant, level of expected variability—just as there is for one batch of brand-name medicine compared with the next batch of brand-name product. This variability can and does occur during manufacturing, for both brand-name and generic medicines. When a medicine, generic or brand-name, is mass produced, very small variations in purity, size, strength, and other parameters are permitted. FDA limits how much variability is acceptable.

For example, a very large research study1 comparing generics with brand-name medicines, found that there were very small differences (approximately 3.5%) in absorption into the body between generic and brand-name medicines. Some generics were absorbed slightly more, some slightly less. This amount of difference is expected and clinically acceptable, whether for one batch of brand-name medicine tested against another batch of the same brand, or for a generic tested against a brand-name medicine. 

Additional Resource

Research study: Clinical equivalence of generic and brand-name drugs used in cardiovascular disease
A study of 38 published clinical trials showed no evidence that brand-name heart medicines worked any better than generic heart medicines.

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Why does a generic drug look different from the brand drug?

Trademark laws in the United States do not allow a generic drug to look exactly like other drugs already on the market. Generic medicines and brand-name medicines share the same active ingredient, but other characteristics, such as colors and flavorings, that do not affect the performance, safety, or effectiveness of the generic medicine, may be different.

Additional Resource

The importance of the physical characteristics of generic drugs
Read a discussion of FDA’s guidance recommending that generic applicants design and develop generic drugs with a similar size and shape to the brand name product. 

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Why do generic medicines often cost less than the brand-name medicines?

Generic drugs are approved only after a rigorous review by FDA and after a set period of time that the brand product has been on the market exclusively. This is because new drugs, like other new products, are usually protected by patents that prohibit others from making and selling copies of the same drug.  

Generic drugs tend to cost less than their brand-name counterparts because generic drug applicants do not have to repeat animal and clinical (human) studies that were required of the brand-name medicines to demonstrate safety and effectiveness. This abbreviated pathway is why the application is called an “abbreviated new drug application.” 

The reduction in upfront research costs means that, although generic medicines have the same therapeutic effect as their branded counterparts, they are typically sold at substantial discounts, an estimated 80 to 85% less, compared with the price of the brand-name medicine. According to the IMS Health Institute, generic drugs saved the U.S. healthcare system nearly $2.2 trillion from 2009 to 20192.

When multiple generic companies are approved to market a single product, more competition exists in the marketplace, which typically results in lower prices for patients.
Bringing more drug competition to the market and addressing the high cost of medicines is one of FDA’s top priorities. In 2017, FDA announced the Drug Competition Action Plan (DCAP) to further encourage robust and timely market competition for generic drugs and help bring greater efficiency and transparency to the generic drug review process, without sacrificing the scientific rigor underlying our generic drug program.



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What standards must generic medicines meet to receive FDA approval?

Drug companies must submit an abbreviated new drug application (ANDA) to FDA for approval to market a generic drug that is the same as (or bioequivalent to) the brand product. FDA reviews the application to ensure drug companies have demonstrated that the generic medicine can be substituted for the brand-name medicine that it copies.

An ANDA must show the generic medicine is equivalent to the brand in the following ways:

  • The active ingredient is the same as that of the brand-name drug/innovator drug.
    • An active ingredient in a medicine is the component that makes it pharmaceutically active — effective against the illness or condition it is treating.
    • Generic drug companies must provide scientific evidence that shows that their active ingredient is the same as that of the brand-name medicine they copy, and FDA must review that evidence.
  • The generic medicine is the same strength.
  • The medicine is the same type of product (such as a tablet or an injectable).
  • The medicine has the same route of administration (such as oral or topical).
  • It has the same use indications.
  • The inactive ingredients of the medicine are acceptable.
    • Some differences, which must be shown to have no effect on how the medicine functions, are allowed between the generic and the brand-name product.
    • Generic drug companies must submit evidence that all the ingredients used in their products are acceptable, and FDA must review that evidence.
  • It lasts for at least the same amount of time.
    • Most medicines break down, or deteriorate, over time.
    • Generic drug companies must do months-long "stability tests" to show that their products last for at least the same amount of time as the brand-name product.
  • It is manufactured under the same strict standards as the brand-name medicine.
    • It meets the same batch requirements for identity, strength, purity, and quality.
    • The manufacturer is capable of making the medicine correctly and consistently.
      • Generic drug manufacturers must explain how they intend to manufacture the medicine and must provide evidence that each step of the manufacturing process will produce the same result each time. FDA scientists review those procedures, and FDA inspectors go to the generic drug manufacturer's facility to verify that the manufacturer is capable of making the medicine consistently and to check that the information the manufacturer has submitted to FDA is accurate.
      • Often, different companies are involved (such as one company manufacturing the active ingredient and another company manufacturing the finished medicine). Generic drug manufacturers must produce batches of the medicines they want to market and provide information about the manufacturing of those batches for FDA to review.
  • The container in which the medicine will be shipped and sold is appropriate.
  • The label is the same as the brand-name medicine's label.
    • The drug information label for the generic medicine should be the same as the brand-name label. One exception is if the brand-name drug is approved for more than one use and that use is protected by patents or exclusivities. A generic medicine can omit the protected use from its labeling and only be approved for a use that is not protected by patents or exclusivities, so long as that removal does not take away information needed for safe use. Labels for generic medicines can also contain certain changes when the drug is manufactured by a different company, such as a different lot number or company name.
  • Relevant patents or exclusivities are addressed.
    • As an incentive to develop new medicines, drug companies are awarded patents and exclusivities that may delay FDA approval of applications for generic medicines. FDA must comply with the delays in approval that the patents and exclusivities impose.

The ANDA process does not, however, require the drug applicant to repeat costly animal and clinical (human studies) on ingredients or dosage forms already approved for safety and effectiveness. This allows generic medicines to be brought to market more quickly and at lower cost, allowing for increased access to medications by the public.

Additional Resources

What Is the Approval Process for Generic Drugs?
Detailed information on the critical factors the FDA reviews to make sure a generic medicine is as safe and effective as the brand-name drug.

The Generic Drug Approval Process, CDER Conversation
An interview on how FDA reviews generic medicines with Ted Sherwood, Director, Office of Regulatory Operations, Office of Generic Drugs, Center for Drug Evaluation and Research.

What Makes a Generic the Same as a Brand-Name Drug?
Download a high-resolution, printable PDF of this infographic (PDF - 431 KB).

What makes a generic the same as a brand name drug?

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Is a generic of my brand-name medicine available?

In addition to asking your local pharmacist for assistance, there are three ways to find out if there is a generic of your brand-name medicine available:

  • Use Drugs@FDA, a catalog of FDA-approved drug products, including their drug labeling.
    • First, search by brand name.
    • Second, select the brand name product and note which products are listed under the section labeled “Therapeutic Equivalents for ...”
    • Products that include an ANDA (not NDA) number next to the name are generic products.
  • Use the online version of the Orange Book.  
    • First, search by proprietary or brand name. Note the active ingredient name.
    • Second, search again by the active ingredient name.
    • Scroll right to find the dosage form (for example: tablet) and strength.
    • Next, scroll right to the TE Code column. If the TE column contains a code beginning with “A,” FDA has approved generic equivalents.
    • Finally, look at the column “Appl No.” If the letter “A” appears before the number, that product is an FDA-approved generic for the brand-name drug.  
    • For very recent approvals, consult First Generic Drug Approvals.


If you are unable to locate a generic of your brand-name medicine, it may be that the brand-name medicine is still within the period of time when it has exclusive rights to the marketplace, which allows drug companies to recoup their costs for the initial research and marketing of the brand-name or innovator drug. It is only after both patent and other periods of exclusivity are resolved that FDA can approve a generic of the brand-name medicine.

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How Does FDA monitor side effects or safety issues with generic medicines?

FDA takes several actions to ensure safety and quality before and after a new or generic medicine is approved. When a generic drug application is submitted, FDA conducts a thorough examination of the data submitted by the applicant and evaluates information obtained by FDA investigators while inspecting the related testing and manufacturing facilities to ensure that every generic drug is safe, effective, high quality, and substitutable to the brand name drug.

FDA staff continually monitors all approved drug products, including generics, to make certain the medicines at all levels of the supply chain, from active pharmaceutical ingredients (APIs) to products being sold to consumers, are safe, effective, and high quality.

FDA also monitors and investigates reports of negative patient side effects or other reactions. The investigations may lead to changes in how a product (brand-name and generic) is used or manufactured, and FDA will make recommendations to health care professionals and the public if the need arises.

MedWatch is the FDA’s medical product safety reporting program. Health professionals, patients and consumers can use MedWatch to voluntarily report a serious adverse event, product quality problem, product use/medication error, or therapeutic inequivalence/failure that is suspected to be associated with the use of an FDA-regulated drug, biologic, medical device, dietary supplement or cosmetic.

Additional Resource

Postmarketing Surveillance of Generic Drugs

Download a high-resolution, printable PDF of this infographic (PDF - 282 KB)

Postmarketing Surveillance


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Where can I find more information about generic medicines?

Contact your doctor, pharmacist, or other health care provider for information on generic medicines. For more information, you can also:


1Davit et al. Comparing generic and innovator drugs: a review of 12 years of bioequivalence data from the United States Food and Drug Administration. Ann Pharmacother. 2009;43(10):1583-97.

2Association for Accessible Medicines. 2020 Generic Drug & Biosimilars Access & Savings in the U.S. Report. Available from: https://accessiblemeds.org/sites/default/files/2020-09/AAM-2020-Generics-Biosimilars-Access-Savings-Report-US-Web.pdf. Available from: http://www.imshealth.com/en/thought-leadership/quintilesims-institute/reports

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