diff --git a/docs/en/observability/synthetics-command-reference.asciidoc b/docs/en/observability/synthetics-command-reference.asciidoc
index 66e39d52de..18dd0882c2 100644
--- a/docs/en/observability/synthetics-command-reference.asciidoc
+++ b/docs/en/observability/synthetics-command-reference.asciidoc
@@ -72,6 +72,11 @@ Runs with the browser in headful mode.
 +
 This is the same as running `--playwright-options '{"headless": false}'`.
 
+[NOTE]
+=====
+Headful mode is only to be used locally when testing, to help see the browser being shown and to interact with DOM elements. Do not attempt to run in headful mode when running through Elastic's global managed testing infrastructure, or {private-location}s.
+=====
+
 `-h, --help`::
 Shows help for the `npx @elastic/synthetics` command.