Why is Suxiao Jiuxin Pill taken sublingually during an angina attack?

You can look in the mirror, stick out your tongue, and then use your tongue to reach the tip of your nose - see? There are blood vessels in very shallow places under the tongue. The pills will quickly enter the blood when held under the tongue, so that they can be used for first aid. If swallowed, it will be absorbed through the gastrointestinal tract and then into the bloodstream too slowly.