REMS Requirements: Risk Evaluation and Mitigation Strategies Explained
A Risk Evaluation and Mitigation Strategy (REMS) is a drug safety program that FDA can require under Section 505-1 of the FD&C Act (added by FDAAA 2007) when it determines that a REMS is necessary to ensure that the benefits of a drug outweigh its risks. REMS can include one or more elements: a Medication Guide or Patient Package Insert, a Communication Plan for healthcare providers, and Elements to Assure Safe Use (ETASU) such as prescriber certification, pharmacy certification, or patient registries. All REMS require periodic assessment reports to FDA.
Key Takeaways
Key Takeaways
- REMS are FDA-mandated safety programs established under FDAAA 2007, required when labeling alone cannot adequately manage a drug's serious risks.
- Three REMS elements exist: Medication Guide/Patient Package Insert, Communication Plan, and Elements to Assure Safe Use (ETASU) such as prescriber/pharmacy certification.
- Approximately 60-70 drugs have active REMS programs as of 2026; failure to comply results in misbranding under Section 502(y)/(z) of the FD&C Act.
- The CREATES Act (2019) provides a remedy when REMS are used as barriers to generic drug access.
What Is a REMS?
A REMS is a strategy that goes beyond professional labeling to manage a known or potential serious risk associated with a drug product. REMS are not voluntary — when FDA determines that a REMS is necessary, the applicant must develop and implement the REMS as a condition of approval (for new applications) or as a post-marketing requirement (for already-approved products).
REMS occupy a specific position in FDA's risk management toolkit: they are more restrictive than labeling changes alone but less restrictive than withdrawing the product from the market. The goal is to allow patients to access drugs with serious risks when those risks can be managed through specific mitigation measures.
Statutory Authority
REMS authority comes from Section 505-1 of the FD&C Act, as added by the FDA Amendments Act of 2007 (FDAAA). Key provisions:
| Section | Authority |
|---|---|
| 505-1(a) | FDA may require a REMS if necessary to ensure benefits outweigh risks |
| 505-1(e) | Elements of a REMS (Medication Guide, Communication Plan) |
| 505-1(f) | Elements to Assure Safe Use (ETASU) |
| 505-1(g) | REMS assessment requirements |
| 505-1(h) | Modification and termination of REMS |
| 505(o)(4) | Authority to require labeling changes (related but distinct) |
When FDA Requires a REMS
FDA can require a REMS in three circumstances:
- As a condition of approval for a new NDA, BLA, or ANDA. FDA determines during the review process that a REMS is necessary. The applicant must develop and submit the REMS before approval.
- Post-approval for an already-marketed drug. FDA determines based on new safety information that a REMS is necessary. FDA can require an approved application holder to submit a proposed REMS.
- As a condition of ANDA approval. If the Reference Listed Drug (RLD) has a REMS, the ANDA applicant must either adopt the same REMS (shared REMS) or develop an alternative REMS that FDA determines is equally effective.
Criteria for Requiring a REMS
FDA considers the following factors when determining whether a REMS is necessary (Section 505-1(a)):
| Factor | Considerations |
|---|---|
| Seriousness of the known or potential risk | Severity and reversibility of the adverse event |
| Size of the population likely to use the drug | Number of patients exposed to the risk |
| Expected benefit of the drug | Therapeutic benefit relative to available alternatives |
| Seriousness of the disease or condition | Whether the drug treats a serious or life-threatening condition |
| Expected or actual duration of treatment | Chronic use increases cumulative risk exposure |
| Whether the drug is a new molecular entity | Novel drugs may have less characterized risk profiles |
Elements of a REMS
Overview of REMS Elements
A REMS can include one or more of the following elements, in order of increasing restrictiveness:
| Element | Description | Restrictiveness |
|---|---|---|
| Medication Guide | Patient-directed labeling distributed at every dispensing | Least restrictive |
| Patient Package Insert | Information sheet included in the drug packaging | Low |
| Communication Plan | Outreach to healthcare providers about the drug's risks | Moderate |
| Elements to Assure Safe Use (ETASU) | Active restrictions on prescribing, dispensing, or use | Most restrictive |
| Implementation System | Infrastructure to support ETASU | Required with ETASU |
A REMS is not required to include all elements. Many REMS consist only of a Medication Guide. The most restrictive REMS include ETASU with multiple components.
Medication Guide
Regulatory basis: 21 CFR Part 208 and Section 505-1(e)(2)
A Medication Guide is FDA-approved patient labeling that must be distributed with each dispensing of the drug product. Medication Guides are required when FDA determines that patient labeling could help prevent serious adverse effects, that the drug has serious risks relative to benefits and patient adherence is critical, or that the drug has important limitations on safe use.
Requirements:
- Must be written in language understandable to patients
- Must be distributed by the pharmacist to the patient at every dispensing
- Must be in the specific format prescribed by 21 CFR 208.24
- Must be updated when labeling changes are made to the prescribing information
Medication Guide content (21 CFR 208.24):
| Section | Content |
|---|---|
| Header | Drug name, "Medication Guide" header |
| What is the most important information | Most serious risks |
| What is [drug name]? | Description of the drug and its uses |
| Who should not take [drug name]? | Contraindications in patient language |
| How should I take [drug name]? | Dosing instructions |
| What should I avoid? | Drug interactions, activities to avoid |
| What are the possible side effects? | Common and serious side effects |
| How should I store [drug name]? | Storage conditions |
| General information | Additional safety information |
Patient Package Insert
A Patient Package Insert (PPI) is an FDA-approved document included inside the product packaging. Unlike a Medication Guide (which is distributed by the pharmacist), a PPI is physically included with the drug product.
PPIs are currently required for only a few product categories (e.g., oral contraceptives under 21 CFR 310.501, estrogen-containing products under 21 CFR 310.515). However, REMS can include a PPI as an element under Section 505-1(e)(2).
Communication Plan
Regulatory basis: Section 505-1(e)(3)
A Communication Plan is a REMS element that uses specific outreach to healthcare providers to inform them about the drug's serious risks. Communications plans may include:
| Communication Type | Description |
|---|---|
| Dear Healthcare Provider (DHCP) letters | Letters sent to prescribers describing specific risks |
| Professional society outreach | Presentations or materials distributed through medical societies |
| Continuing education programs | FDA-approved CME/CE programs about the drug's risks |
| Informational websites | FDA-approved websites with provider-directed safety information |
| Training materials | Materials that educate prescribers on safe prescribing practices |
Key requirements:
- All Communication Plan materials must be approved by FDA before distribution
- The applicant must track distribution and effectiveness of communications
- Communication Plan content must be consistent with the approved labeling
- Communications cannot be promotional in nature
Elements to Assure Safe Use (ETASU)
Regulatory basis: Section 505-1(f)
ETASU are the most restrictive REMS elements. They impose conditions on how the drug is prescribed, dispensed, and used. ETASU can only be required when FDA determines that the REMS with Medication Guide and/or Communication Plan alone would be insufficient.
Section 505-1(f)(3) specifies the types of ETASU that FDA may require:
| ETASU Type | Description | Example |
|---|---|---|
| Prescriber certification | Healthcare providers must complete training and be certified before prescribing | iPLEDGE (isotretinoin): prescribers must enroll and complete training |
| Pharmacy certification | Pharmacies must be certified and follow specific dispensing procedures | Clozapine REMS: pharmacies must verify patient monitoring |
| Patient enrollment/registry | Patients must be enrolled in a registry before receiving the drug | THALOMID REMS (thalidomide): mandatory pregnancy registry |
| Dispensing restrictions | Drug can only be dispensed in certain healthcare settings | Certain cell and gene therapies: only at certified treatment centers |
| Monitoring requirements | Specific tests or monitoring must be performed before/during treatment | Clozapine REMS: mandatory ANC monitoring before dispensing |
| Quantity limits | Restrictions on the quantity prescribed or dispensed | iPLEDGE: 30-day supply maximum |
| Documentation requirements | Evidence of safe-use conditions before dispensing | Pregnancy testing requirements before dispensing teratogenic drugs |
Statutory limitation on ETASU: Section 505-1(f)(2) states that ETASU shall not be unduly burdensome on patient access to the drug, particularly for patients with serious or life-threatening diseases. ETASU must be commensurate with the specific serious risk and must not be designed to restrict access beyond what is necessary for safety.
Implementation System
When a REMS includes ETASU, the applicant must also have an implementation system — the operational infrastructure to support the ETASU. This typically includes:
| Component | Purpose |
|---|---|
| Database/registry system | Track enrolled prescribers, pharmacies, and patients |
| Verification system | Confirm safe-use conditions are met before dispensing |
| Call center | Support healthcare providers and patients with REMS questions |
| Training platform | Deliver prescriber and pharmacy certification training |
| Compliance monitoring | Track adherence to REMS requirements |
| Reporting system | Generate data for REMS assessment reports |
REMS Assessment Schedule
Mandatory Assessment Reporting
Section 505-1(g) requires applicants to submit REMS assessment reports to FDA on a specified schedule. The assessment evaluates whether the REMS is meeting its goals.
Default assessment schedule (per Section 505-1(g)(2)):
| Timing | Assessment Due |
|---|---|
| 18 months after approval | First assessment |
| 3 years after approval | Second assessment |
| 7 years after approval | Third assessment |
| As specified by FDA | Additional assessments |
FDA may require a different schedule based on the specific REMS. Many REMS specify more frequent assessments, particularly in the first few years:
| Alternative Schedule | When Used |
|---|---|
| Every 6 months for first 2 years | High-risk drugs requiring close monitoring |
| Annually | Drugs with moderate risk requiring regular evaluation |
| At FDA's request | When new safety information emerges |
REMS Assessment Content
A REMS assessment report must include:
| Section | Content |
|---|---|
| REMS goals | Restatement of the safety goals the REMS is designed to achieve |
| Assessment metrics | Quantitative measures of REMS performance |
| Survey results | Knowledge, attitude, and behavior surveys of prescribers and/or patients |
| Adverse event data | Rates of the specific adverse events the REMS addresses, compared to baseline |
| ETASU compliance data | Prescriber certification rates, pharmacy certification rates, patient enrollment numbers (if applicable) |
| Implementation system performance | System uptime, call center metrics, processing times |
| Proposed REMS modifications | If the assessment identifies the need for changes |
| Overall assessment | Whether the REMS is meeting its goals |
Metrics for REMS Effectiveness
FDA evaluates REMS effectiveness using metrics tailored to the specific REMS goals:
| REMS Goal | Assessment Metrics |
|---|---|
| Prevent use in contraindicated patients | Rate of use in contraindicated populations, survey of prescriber knowledge |
| Ensure monitoring before treatment | Rate of required testing before dispensing, pharmacy compliance rates |
| Prevent fetal exposure (teratogenic drugs) | Pregnancy rates among patients, compliance with pregnancy testing requirements |
| Ensure prescribers understand risks | Prescriber knowledge and behavior surveys |
| Prevent off-label use for unsafe purposes | Prescription patterns, indications captured in registries |
Shared REMS
The Shared REMS Requirement
Section 505-1(i)(1) of the FD&C Act requires that ANDA and 505(b)(2) applicants whose RLD has a REMS with ETASU use a single, shared system with the NDA holder. This prevents the creation of multiple duplicative REMS programs for the same drug.
Key principles of shared REMS:
| Principle | Description |
|---|---|
| Single system | One REMS program covers both the innovator and generic products |
| Shared ETASU | The same ETASU elements apply to all versions of the product |
| Cost sharing | Costs of the REMS program are shared among all applicants on commercially reasonable terms |
| Equal access | Generic manufacturers must have access to the shared REMS on the same terms as the innovator |
The REMS as a Barrier to Generic Entry
The shared REMS requirement has been a contentious issue. In some cases, innovator companies have been accused of using REMS programs to block generic competition by refusing to provide samples needed for bioequivalence testing or by refusing to engage in shared REMS negotiations.
The Creating and Restoring Equal Access to Equivalent Samples (CREATES) Act, signed into law in December 2019 as part of the Further Consolidated Appropriations Act, 2020, provides a legal remedy. Under CREATES, a generic applicant can bring a federal court action against an innovator that refuses to sell samples needed for testing or that fails to negotiate a shared REMS in good faith.
Shared REMS vs. Individual REMS
| Feature | Shared REMS | Individual REMS |
|---|---|---|
| When used | Multiple applicants for same active ingredient with ETASU | Single applicant with unique REMS |
| System | One system for all products | Independent system |
| Cost | Shared among applicants | Borne by single applicant |
| Modification | Requires agreement or FDA order | Applicant proposes, FDA approves |
| Example | Clozapine REMS (shared across all clozapine manufacturers) | Product-specific programs |
REMS Modification
When REMS Modification Occurs
REMS are not static. They may be modified when:
| Trigger | Initiator | Process |
|---|---|---|
| New safety data changes risk profile | Applicant or FDA | Applicant proposes modification; FDA reviews |
| REMS assessment shows goals not met | FDA or applicant | REMS elements strengthened |
| REMS assessment shows goals are met and elements can be reduced | Applicant | Applicant proposes modification; FDA reviews |
| REMS is unduly burdensome | Applicant | Applicant proposes modification; FDA evaluates |
| FDA determines REMS is no longer necessary | FDA | REMS terminated |
| Generic entry requires shared REMS | ANDA applicant | Shared REMS negotiated |
Modification Process
Under Section 505-1(h), REMS modifications follow this process:
- Applicant-initiated modification: The applicant submits a proposed REMS modification to FDA as a supplement. The modification may add, remove, or change REMS elements. FDA reviews and approves or requests changes.
- FDA-initiated modification: FDA can require modifications if it determines the current REMS is insufficient. FDA communicates the required changes, and the applicant submits a proposed modified REMS.
- Timeline: FDA has 180 days to act on a REMS modification submission.
Reducing or Eliminating REMS
An applicant can request that FDA reduce or eliminate REMS requirements if data show the REMS goals are being met and the safety risk is adequately managed through other means (e.g., labeling alone).
FDA considers:
- Accumulated safety data showing the risk is lower than initially assessed
- Effectiveness of labeling in communicating the risk
- Whether ETASU can be replaced by less restrictive elements
- Burden on patient access
- Duration since approval and amount of real-world experience
Notable REMS Programs
iPLEDGE (Isotretinoin)
| Feature | Details |
|---|---|
| Drug | Isotretinoin (all brands) |
| Primary risk | Severe teratogenicity (birth defects) |
| REMS type | Shared REMS with ETASU |
| Key ETASU elements | Prescriber certification, pharmacy certification, patient enrollment, pregnancy prevention program, pregnancy testing before each dispensing, 30-day dispensing limit, 7-day prescription window |
| Assessment | Regular assessments including pregnancy rate monitoring |
Clozapine REMS
| Feature | Details |
|---|---|
| Drug | Clozapine (all manufacturers) |
| Primary risk | Severe neutropenia (potentially fatal agranulocytosis) |
| REMS type | Shared REMS with ETASU |
| Key ETASU elements | Prescriber certification, pharmacy certification, patient enrollment, mandatory Absolute Neutrophil Count (ANC) monitoring before dispensing, no dispensing without current ANC |
| Assessment | ANC monitoring compliance, neutropenia rates |
THALOMID REMS (Thalidomide)
| Feature | Details |
|---|---|
| Drug | Thalidomide (Thalomid) |
| Primary risk | Severe teratogenicity |
| REMS type | REMS with ETASU |
| Key ETASU elements | Prescriber certification, pharmacy certification, patient enrollment, pregnancy prevention program, mandatory pregnancy testing, restricted distribution |
| Historical context | Thalidomide disaster of the 1960s drove the most restrictive REMS elements |
Opioid Analgesics REMS
| Feature | Details |
|---|---|
| Drugs | Extended-release and long-acting opioid analgesics |
| Primary risk | Addiction, abuse, misuse, overdose, death |
| REMS type | Shared REMS with Communication Plan |
| Key elements | Prescriber training (CE-accredited), patient counseling guide, Medication Guide |
| Note | This REMS does not include ETASU (no prescriber certification requirement) — FDA determined that ETASU would unduly burden patient access to pain management |
Transmucosal Immediate-Release Fentanyl (TIRF) REMS
| Feature | Details |
|---|---|
| Drugs | Transmucosal fentanyl products (Actiq, Fentora, etc.) |
| Primary risk | Fatal respiratory depression, particularly in opioid-non-tolerant patients |
| REMS type | Shared REMS with ETASU |
| Key ETASU elements | Prescriber enrollment (must attest understanding of risks), pharmacy enrollment, patient-prescriber agreement, outpatient pharmacies must verify prescriber enrollment before dispensing |
REMS and eCTD Submissions
Filing REMS Documents
REMS documents are submitted within the eCTD framework:
| REMS Document | eCTD Location | Submission Type |
|---|---|---|
| REMS document (the REMS itself) | Module 1.14.1 | Part of original application or supplement |
| Medication Guide | Module 1.14.1 | With labeling supplement |
| REMS assessment report | Module 1.14.1 | As specified in REMS timetable |
| Communication Plan materials | Module 1.14.1 | With supplement |
| ETASU documentation | Module 1.14.1 | With supplement |
| Proposed REMS modifications | Module 1.14.1 | As supplement |
Supplement Types for REMS Changes
| REMS Action | Supplement Type |
|---|---|
| Initial REMS (with new application) | Part of original NDA/BLA |
| REMS modification (adding ETASU) | PAS |
| REMS modification (reducing elements) | PAS or CBE-30 depending on change |
| Medication Guide update (safety) | CBE-0 |
| Communication Plan material update | CBE-30 or PAS |
| REMS assessment report | Not a supplement; separate submission type |
REMS Compliance Monitoring
FDA Oversight
FDA monitors REMS compliance through:
| Mechanism | Description |
|---|---|
| REMS assessment reviews | FDA reviews each assessment report and may request additional information |
| GMP inspections | FDA inspectors may evaluate REMS implementation during manufacturing inspections |
| Compliance programs | FDA's Office of Compliance monitors REMS adherence |
| REMS website | FDA maintains a public list of all approved REMS at www.fda.gov/drugs/rems |
| Signal detection | FDA monitors adverse event data related to REMS-managed risks |
Consequences of REMS Non-Compliance
| Violation | Consequence |
|---|---|
| Failure to implement required REMS | Misbranding; product is deemed misbranded under Section 502(y)/(z) |
| Failure to submit REMS assessment | Warning Letter; potential enforcement action |
| Distributing product without required REMS elements | Misbranding action; potential injunction |
| Prescribing outside REMS requirements | Prescriber may be decertified from the REMS program |
| Pharmacy dispensing without REMS verification | Pharmacy may be decertified; potential Board of Pharmacy action |
Key Regulatory References
| Reference | Description |
|---|---|
| Section 505-1, FD&C Act (FDAAA 2007) | REMS statutory authority |
| Section 505(o)(4), FD&C Act | Related labeling change authority |
| 21 CFR Part 208 | Medication Guide requirements |
| FDAAA 2007 (Public Law 110-85) | FDA Amendments Act establishing REMS |
| CREATES Act (2019) | Remedy for REMS-related barriers to generic access |
| FDA Guidance: Format and Content of Proposed REMS (Sep 2009) | REMS submission guidance |
| FDA Guidance: REMS Assessment Planning and Reporting (Oct 2019) | Assessment report content and process |
| FDA Guidance: Medication Guides (Nov 2011) | Medication Guide development and distribution |
| FDA Guidance: Communication Plan REMS Element (Nov 2014) | Communication Plan content |
| FDA REMS Website | www.fda.gov/drugs/rems — current list of all approved REMS |
References
As of 2026, approximately 60-70 drugs have active REMS programs. This number changes as new REMS are approved and existing REMS are terminated. FDA maintains a current list on its REMS website. The number is relatively small compared to the total number of approved drugs, reflecting that REMS are reserved for products with specific, serious risks that cannot be managed through labeling alone.