U.S. Pharmacopeial Convention

Prescription Container Labeling


Medication misuse has resulted in more than one million adverse drug events per year in the United States.  Patients’best source (and often only source) of information regarding the medications they have been prescribed is on the prescription container label Although other written information and oral counseling sometimes may be available, the prescription container label must fulfill the professional obligations of the prescriber and pharmacist.  These obligations include giving the patient the most essential information needed to understand how to safely and appropriately use the medication and to adhere to the prescribed medication regimen.

Inadequate understanding of prescription directions for use and auxiliary information on dispensed containers is widespread.  Studies have found that 46% of patients misunderstood one or more dosage instructions, and 56% misunderstood one or more auxiliary warnings.  The problem of misunderstanding is particularly troublesome in patients with low or marginal literacy and in patients receiving multiple medications that are scheduled for administration using unnecessarily complex, non-standardized time periods.  In one study, patients with low literacy were 34 times more likely to misinterpret prescription medication warning labels.  However, even patients with adequate literacy often misunderstand common prescription directions and warnings.  In addition, there is great variability in the actual auxiliary warning and supplemental instructional information applied by individual practitioners to the same prescription.  The specific evidence to support a given auxiliary statement often is unclear, and patients often ignore such information.  The essential need for, and benefit of, auxiliary label information (both text and icons) in improving patient understanding about safe and appropriate use of their medications vs. explicit simplified language alone require further study.

Lack of universal standards for labeling on dispensed prescription containers is a root cause for patient misunderstanding, non-adherence, and medication errors.  On 18 May 2007 the USP Safe Medication Use Expert Committee established an Advisory Panel to: 1) determine optimal prescription label content and format to promote safe medication use by critically reviewing factors that promote or distract from patient understanding of prescription medication instructions and 2) create universal prescription label standards for format/appearance and content/language.

In November 2009, the Health Literacy and Prescription Container Labeling Advisory Panel presented its recommendations to the Safe Medication Use Expert Committee, which then requested that USP develop patient-centered label standards for the format, appearance, content, and language of prescription medication instructions to promote patient understanding. These recommendations form the basis of this general chapter.

Note:  These standards do not apply when a prescription drug will be administered to a patient by licensed personnel who are acting within his or her scope of practice.

Prescription Container Label Standards to Promote Patient Understanding

Organize the prescription label in a patient-centered manner.  Information shall be organized in a way that best reflects how most patients seek out and understand medication instructions. Prescription container labeling should feature only the most important patient information needed for safe and effective understanding and use.

Emphasize instructions and other information important to patients.  Prominently display information that is critical for patients' safe and effective use of the medicine.  At the top of the label specify the patient's name, drug name (spell out full generic and brand name) and strength, and explicit clear directions for use in simple language.

The prescription directions should follow a standard format so the patient can expect that each element will be in a regimented order each time a prescription is received.

Other less critical but important content (e.g., pharmacy name and phone number, prescriber name, fill date, refill information, expiration date, prescription number, drug quantity, physical description, and evidence-based auxiliary information) should not supersede critical patient information.  Such less critical information should be placed away from dosing instructions (e.g., at the bottom of the label or in another less prominent location) because it distracts patients, which can impair their recognition and understanding.

Simplify language.  Language on the label should be clear, simplified, concise, and familiar and should be used in a standardized manner. Only common terms and sentences should be used.  Do not use unfamiliar words (including Latin terms) or medical jargon.

Use of readability formulas and software is not recommended to simplify short excerpts of text like those on prescription labels. Instead, use simplified, standardized sentences that have been developed to ensure ease of understanding the instructions correctly (by seeking feedback from samples of diverse consumers).

Give explicit instructions.  Instructions for use (i.e., the SIG or signatur) should clearly separate the dose itself from the timing of each dose in order to explicitly convey the number of dosage units to be taken and when (e.g., specific time periods each day such as morning, noon, evening, and bedtime).  Instructions shall include specifics on time periods.  Do not use alphabetic characters for numbers.  For example, write, “Take 2 tablets in the morning and 2 tablets in the evening” rather than “Take two tablets twice daily.”

Whenever available, use standardized directions (e.g., write “Take 1 tablet in the morning and 1 tablet in the evening” if the prescription reads b.i.d.).  Vague instructions based on dosing intervals such as twice daily, 3 times daily, or hourly intervals such as every 12 hours generally should be avoided because such instructions are implicit rather than explicit, they may involve numeracy skills, and patient interpretation may vary from prescriber intent.  Although instructions that use specific hourly times (e.g., 8 a.m. and 10 p.m.) may seem to be more easily understood than implicit vague instructions, recommending dosing by precise hours of the day is less readily understood and may present greater adherence issues due to individual lifestyle patterns, e.g., shift work, than more general time frames such as in the morning, in the evening, after breakfast, with lunch, or at bedtime.  Consistent use of the same terms should help avoid patient confusion.

Ambiguous directions such as “take as directed” should be avoided unless clear and unambiguous supplemental instructions and counseling are provided (e.g., directions for use that will not fit on the prescription container label).  A clear statement referring the patient to such supplemental materials should be included on the container label.

Include purpose for use.  If the purpose of the medication is included on the prescription, it should be included on the prescription container label unless the patient prefers that it not appear.  Always ask patients their preference when prescriptions are submitted for filling.  Confidentiality and FDA approval for intended use (e.g., labeled vs. off-label use) may limit inclusion of the purpose on labels.  Current evidence supports inclusion of purpose-for-use language in clear, simple terms (e.g., for high blood pressure rather than for hypertension).

Limit auxiliary information.  Auxiliary information on the prescription container label should be evidence based in simple explicit language that is minimized to avoid distracting patients with nonessential information.  Most patients, particularly those with low literacy, pay little attention to auxiliary information.  The information should be presented in a standardized manner and should be critical for patient understanding and safe medication use (e.g., warnings and critical administration alerts).  Icons are frequently misunderstood by patients.  In addition, icons that provide abstract imagery for messages that are difficult to visually depict may be ineffective at improving understanding compared with simplified text alone.  Use only icons for which there is adequate evidence, through consumer testing, that they improve patient understanding about correct use.  Evidence-based auxiliary information, both text and icons, should be standardized so that it is applied consistently and does not depend on individual practitioner choice.

Address limited English proficiency.  Whenever possible, the directions for use on a prescription container label should be provided in the patient’s preferred language.  Otherwise there is a risk of misinterpretation of instructions by patients with limited English proficiency, which could lead to medication errors and adverse health outcomes.  Additionally, whenever possible, directions for use should appear in English as well, to facilitate counseling; the drug name shall be in English so that emergency personnel and other intermediaries can have quick access to the information.

Translations of prescription medication labels should be produced using a high-quality translation process.  An example of a high-quality translation process is:

  • Translation by a trained translator who is a native speaker of the target language
  • Review of the translation by a second trained translator and reconciliation of any differences
  • Review of the translation by a pharmacist who is a native speaker of the target language and reconciliation of any differences
  • Testing of comprehension with target audience

If a high-quality translation process cannot be provided, labels should be printed in English and trained interpreter services used whenever possible to ensure patient comprehension.  The use of computer-generated translations should be limited to programs with demonstrated quality because dosage instructions can be inconsistent and potentially hazardous.  Standardized translated instructions and technology advances are needed to ensure the accuracy and safety of prescription container labeling for patients with low English proficiency.

Improve readability.  Labels should be designed and formatted so they are easy to read.  Currently, no strong evidence supports the superiority in legibility of serif vs. sans serif typefaces, so simple uncondensed fonts of either type can be used.

Optimize typography by using:

  • High-contrast print (e.g., black print on white background).
  • Simple, uncondensed familiar fonts with sufficient space within letters and between letters (e.g., Times Roman or Arial).
  • Sentence case (i.e., punctuated like a sentence in English: initial capital followed by lower-case words except proper nouns).
  • Large font size (e.g., minimum 12-point Times Roman or 11-point Arial) for critical information.  Note that point size is not the actual size of the letter, so 2 fonts with the same nominal point size can have different actual letter sizes.  X-height, the height of the lower-case x in typeface, has been used as a more accurate indicator of apparent size than point size.  For example, for a given point size, the x-height and apparent size of Arial are actually bigger than those for Times Roman. Do not use type smaller than 10-point Times Roman or equivalent size of another font. Older adults, in particular, have difficulty reading small print.
  • Adequate white space between lines of text (i.e., 25–30% of the point size).
  • White space to distinguish sections on the label such as directions for use vs. pharmacy information.
  • Horizontal text only.

Other measures can also improve readability:

  • If possible, minimize need to turn the container in order to read lines of text.
  • Never truncate or abbreviate critical information.
  • Highlighting, bolding, and other typographical cues should preserve readability (e.g., high-contrast print and light color for highlighting) and should emphasize patient-centric information or information that facilitates adherence (e.g., refill ordering).
  • Limit the number of colors used for highlighting (e.g., no more than one or two).
  • Use of separate lines to distinguish when each dose should be taken.

Address Visual Impairment

  • Provide alternative access for visually impaired patients (e.g., tactile, auditory, or enhanced visual systems that may employ advanced mechanics or assistivetechnology).