In short: the medicine dissolves fast and goes to work instantly, neutralizing acid on contact. Because the medicines in Alka-Seltzer effervescents are in solution prior to ingestion, they do not require time to dissolve in the stomach like similar active ingredients taken in a tablet form.

Why does Alka-Seltzer work so well?

01 INTRODUCTION. When too much acid builds up in your stomach, you can get heartburn. Alka-Seltzer is a "buffer" which neutralizes stomach acid and temporarily keeps it from becoming too acidic.

What symptoms does Alka-Seltzer treat?

This combination medication is used to temporarily treat cough, stuffy nose, body aches, and other symptoms (e.g., fever, headache, sore throat) caused by the common cold, flu, or other breathing illnesses (e.g., sinusitis, bronchitis).