Adverse Events

{
  "as_of": "2026-10-21T09:00:00Z",
  "caveat": "FAERS report counts: reports are unverified and may be duplicated, a reaction in a report does not mean the drug caused it, and counts cannot estimate how often a reaction occurs. Not medical advice.",
  "data_through": "2026-07-30",
  "drug": "semaglutide",
  "modified": true,
  "reactions": [
    {
      "count": 10674,
      "share": 0.146,
      "term": "nausea"
    },
    {
      "count": 7325,
      "share": 0.1,
      "term": "off label use"
    },
    {
      "count": 6964,
      "share": 0.095,
      "term": "vomiting"
    },
    {
      "count": 6462,
      "share": 0.089,
      "term": "diarrhoea"
    },
    {
      "count": 4905,
      "share": 0.067,
      "term": "decreased appetite"
    }
  ],
  "serious_reports": 36179,
  "serious_share": 0.496,
  "source": {
    "citation": "Data provided by the U.S. Food and Drug Administration (https://open.fda.gov). Normalized by x402 Atlas; not the agency's verbatim record.",
    "name": "openFDA (U.S. Food and Drug Administration)",
    "url": "https://open.fda.gov"
  },
  "total_reports": 72971
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://fda-drugs.use.x402atlas.com/adverse-events?drug=semaglutide&limit=5'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://fda-drugs.use.x402atlas.com/adverse-events?drug=semaglutide&limit=5' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Ffda-drugs.use.x402atlas.com%2Fadverse-events
const res = await pay("https://fda-drugs.use.x402atlas.com/adverse-events?drug=semaglutide&limit=5");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://fda-drugs.use.x402atlas.com/adverse-events?drug=semaglutide&limit=5")
    print(res.status_code, res.text)