Skip to main content

Imprint Code FAQs - For Oral Medications

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Jan 30, 2022.

Need to identify an imprint code? Try the Pill Identifier

What are Imprint Codes?

All approved prescription and over-the-counter solid, oral dosage form medications in the U.S. are required by the Food and Drug Administration (FDA) to have an imprint. This also applies to biological drug products and homeopathic drug products, unless otherwise exempted in the FDA Code of Federal Regulations 206.7. Solid oral dosage forms are defined as capsules, tablets, or similar drug products intended for oral use.

You may need to identify a drug if:

  • you have dropped it or mixed it up in a pill box or case
  • found it in your home or elsewhere
  • you need to double check a medication from the pharmacy that looks different and may be a generic substitution.

Why Do Drugs Have Imprint Codes?

The imprint code, when used in conjunction with the product's size, shape, and color, permits the identification of the drug product, the active ingredient(s), strength, and the manufacturer or distributor of the product.

The purpose of regulating imprinting is to enable identification of the pill ingredients and drug manufacturer by law enforcement officials, health care providers and the patient or caregiver.

  • An imprint is defined as any single letter, number, or combination of letters and numbers, including words, company names, National Drug Code, or a mark, symbol, logo or monogram. The drug manufacturer determines the imprint for specific drug products.
  • Identification of the drug product requires verification of its active ingredients and its dosage strength. Inclusion of a letter or number in the imprint, while not required, is encouraged as a more effective means of identification than a manufacturer's symbol or logo by itself.
  • Homeopathic drug products are required only to bear an imprint that identifies the manufacturer and their homeopathic nature. There are no FDA-approved homeopathic products. Any product being sold in the U.S. that is marked as homeopathic is being marketed without FDA evaluation for safety or effectiveness.

There may be circumstances where two products have the same imprint code. For example, an imprint code might be reused after a drug product has been discontinued. Foreign products may also have the same code as an FDA approved imprint.

What if a Pill or Capsule Does Not Have an Imprint Code?

A solid oral dosage form drug product that does not meet the requirement for imprinting and is not exempt from the requirement may be considered adulterated and misbranded and may be an unapproved new drug as defined by the FDA.

Also, if a pill or capsule does not have an imprint and is not an approved medication it may be:

Do Illegal Drugs, or Other Drugs of Abuse, Have Imprints?

Some illegal drugs, such as Ecstasy, come in tablet formulations of various colors and contain an imprint or design that is appealing to a younger age group, such as a flower, a smiley face, or other common logo.

In addition, other drugs of abuse such as LSD, are often concealed in candy like Sweet Tarts by placing a drop of the drug on the candy. LSD is also commonly placed on sheets of paper imprinted with a design, and then smaller squares of the paper are cut out for illicit trafficking. These imprints, because they are manufactured illegally, are not available for identification in the Pill Identification Wizard.

Prescription medications that are commonly abused, such painkillers, anti-anxiety benzodiazepines, or stimulants can be identified through the Pill Identification Wizard by entering the imprint codes, colors or shapes.

Patients should contact their doctor or pharmacist immediately if they cannot identify their medication.

Popular pill imprint searches

L 484 M 367 LUPIN 500 512
B 7 0 7 022 M 366 R P 5 325
10/325 M523 PLIVA 433 30 M M 365
R 0 3 9 R 180 4H2 R P 10
X ANA X 2 S 90 3 RP 10 325 TEVA 3927
K 56 H 49 377 1 2

Learn More:
Identifying manufacturer imprints and logos


  • Debossed means imprinted with a mark below the dosage form surface.
  • Drug product means a finished dosage form, e.g., a tablet or capsule that contains a drug substance, generally, but not necessarily, in association with one or more other ingredients.
  • Embossed means imprinted with a mark raised above the dosage form surface.
  • Engraved means imprinted with a code that is cut into the dosage form surface after it has been completed.
  • Imprinted means marked with an identification code by means of embossing, debossing, engraving, or printing with ink.
  • Solid oral dosage form means capsules, tablets, or similar drug products intended for oral use.

See also


  1. U.S. Food and Drug Administration. CFR - Code of Federal Regulations Title 21, Subchapter C. Imprinting of Solid Oral Dosage Form Drug Products for Human Use. Revised Sept. 19, 2019. Accessed August 24, 2020 at 
  2. US Food and Drug Administration (FDA). Homeopathic Products. Updated Feb. 11, 2020. Accessed August 24, 2020 at

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.