# FDA FAERS Drug Adverse Events Lookup

> FDA FAERS Drug Adverse Events Lookup is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the top adverse reactions reported for a drug from the FDA FAERS database via openFDA, ranked by report count

## Facts

- Endpoint: GET https://agent402.tools/api/drug-adverse-events
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fda-faers-drug-adverse-events-lookup-258df516
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IJIF_4K6DTGB1CXRypKkD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fda-faers-drug-adverse-events-lookup-258df516
```

Example prompt: Pull the top 10 adverse reactions reported for metformin from the FDA FAERS database so I can see its real-world safety signal.

## When to prefer this

Use this endpoint when you need real-world post-market adverse event data from the FDA FAERS database without requiring an API key. Prefer this over general drug information APIs when the user specifically wants ranked safety signals or pharmacovigilance data from actual patient reports, not curated side-effect lists from drug labels.

## Known failure modes

- Drug name not found in openFDA — returns empty results or 404
- Invalid limit value (outside 1-25 range) — may return error or default
- FDA openFDA API downtime causing upstream failure
- Misspelled or brand-name-only drug not matching generic name in FAERS
- Rate limiting or timeout from upstream FDA API

## How this service works

Top reported adverse reactions for a drug from the FDA FAERS database (openFDA), ranked by report count - a fast read on a drug's real-world safety signal. Live FDA data, no key. ?drug=aspirin&limit=10

## Output

A ranked list of adverse reactions reported for the queried drug in the FDA FAERS system, ordered by report count. Each entry includes the reaction name and the number of times it was reported, giving a fast read on the drug's real-world safety profile.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "drug"
     ],
     "properties": {
      "drug": {
       "type": "string",
       "description": "Drug/medicinal product name"
      },
      "limit": {
       "type": "number",
       "description": "How many top reactions, 1-25 (default 10)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "drug",
      "count",
      "topReactions",
      "source"
     ],
     "properties": {
      "drug": {
       "type": "string"
      },
      "count": {
       "type": "integer"
      },
      "source": {
       "type": "string"
      },
      "topReactions": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "reports": {
          "type": "integer"
         },
         "reaction": {
          "type": "string"
         }
        }
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "drug": "aspirin",
  "count": 2,
  "source": "api.fda.gov (openFDA FAERS, public domain)",
  "topReactions": [
   {
    "reports": 4211,
    "reaction": "NAUSEA"
   },
   {
    "reports": 3987,
    "reaction": "DYSPNOEA"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fda-faers-drug-adverse-events-lookup-258df516/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)