OpenFDA API

Base URL

https://api.fda.gov

Auth

Optional free API key (40 req/min without, 240 req/min with). Register at https://open.fda.gov/apis/authentication/ Pass as: ?api_key=YOUR_KEY

Key Endpoints

Query Parameters

• search — query using OpenFDA syntax
• count — count unique values for a field
• limit — results per request (max 1000)
• skip — pagination offset (max 25000)

Search Syntax

• Field search: field:"value"
• AND: field1:value1+AND+field2:value2
• OR: field1:value1+OR+field2:value2
• Date range: field:[20230101+TO+20231231]
• Wildcards: field:aspir*
• OpenFDA harmonized fields use openfda. prefix

Example Calls

# Adverse events for aspirin
/drug/event.json?search=patient.drug.openfda.brand_name:"aspirin"&limit=5

# Top adverse reactions for a drug
/drug/event.json?search=patient.drug.openfda.generic_name:"metformin"&count=patient.reaction.reactionmeddrapt.exact

# Drug labels by generic name
/drug/label.json?search=openfda.generic_name:"ibuprofen"&limit=3

# Drug recalls in date range
/drug/enforcement.json?search=report_date:[20230101+TO+20231231]&limit=10

# Serious adverse events only
/drug/event.json?search=patient.drug.openfda.brand_name:"warfarin"+AND+serious:1&limit=10

Rate Limits