why am I being denied WebMD access

Might be a cookies, extensions, or plug-ins issue.

Open a Finder window. From the Finder menu bar click Go > Go to Folder

Type or copy paste the following

~/Library/Caches/com.apple.Safari/Cache.db

Click Go then move the Cache.db file to the Trash.

Quit and relaunch Safari to test.

If that didn't help, from the Safari menu bar click Safari > Preferences then select the Extensions tab. Turn that OFF, quit and relaunch Safari to test.

If that helped, turn one extension on then quit and relaunch Safari to test until you find the incompatible extension then click uninstall.

If it's not an extensions issue, try troubleshooting third party plug-ins.

Back to Safari > Preferences. This time select the Security tab. Deselect: Allow plug-ins. Quit and relaunch Safari to test.

If that made a difference, instructions for troubleshooting plugins here.

Ok... check your Firewall settings.

Open System Preferences > Security & Privacy > Firewall

Aside from that, net monitoring apps such as Little Snitch can prevent access to websites.

Try another browser as a test.

Firefox