Raft forming Alginates for Acid Reflux: A Complete Guide With Dosages
blog detail banner

Acid Reflux

Raft-Forming Alginates: Nature’s Fastest Antacids

Jul 21, 2017

When heartburn strikes, the only thing a sufferer is looking for is to cool the burning sensation and get relief. Conventional medications such as PPIs come with their own share of side effects, such as robbing nutrients from the body, and in some cases increasing the risk of an early death . Given the potential risks associated with conventional medications, more and more people are looking at natural alternatives to deal with acid reflux. Raft-forming alginates are one such remedy against symptoms of acid reflux.

How Do Raft-forming Alginates Work Against Acid Reflux?

Alginic acid (algin or alginate) is a polysaccharide compound that is present in brown seaweed (algae). When this compound reacts with water, it forms a viscous gum. Alginate finds use in many industries, including food and printing as well as in manufacturing medical aids and in dentistry.

When used as an antacid, it produces a physical barrier over the stomach contents, which prevents the flow of reflux back into the esophagus. Interestingly, raft-forming alginates act within seconds and provide instant relief from heartburn.

What Does Research Say About Raft-forming Alginates?

In a study that compared the efficacies of an alginate-antacid preparation and a non-raft forming antacid preparation, it was found that alginate preparation formed a mass (raft) close to the esophago-gastric junction (the part where the esophagus ends and the stomach begins). This mass was able to significantly suppress post-prandial (after a meal) reflux compared to a non-raft forming antacid preparation.

In another study, volunteers with symptomatic GERD and hiatal hernias were assigned to two groupsexc. One group was given an alginate-antacid preparation and the other group was given a non-raft forming antacid. After a standard meal, it was found that the group that received the alginate-antacid preparation showed a significant reduction in reflux episodes. Also, the time to acid reflux increased significantly in this group (63 minutes) as compared to the group that received a conventional antacid (14 minutes). This means that alginate-antacid preparation slowed down the occurrence of acid reflux.

Mechanism of Action of Raft-forming Alginates Against Acid Reflux

Raft-forming alginates when consumed precipitate into a low-density viscous gel as soon as they come in contact with gastric acid. An acid pocket forms on top of ingested food; this is the same acid that refluxes into the esophagus after meals. This acid pocket contains an unbuffered (un-neutralized) pool of acid. Alginates form a gel-like raft atop this acid pocket and form a physical barrier that stops the acid from this pocket to reflux back into the esophagus.

The exact location of the raft can be determined by a technique called scintigraphy, which utilizes a radioactive (not harmful to the human body) tracer attached to the raft-forming alginate-antacid preparation. This preparation is given to a volunteer. And, by using a detector called “scintillation counter,” the exact location of the tracer (which has been trapped in the raft-forming alginate) can be determined by the counter.

The refluxate that damages the esophagus contains non-gastric acid components like pepsin and bile acids. And, yet all conventional medications act only by neutralizing the gastric acidity. There is no effective strategy to counter the damaging effects of pepsin and bile acids on the esophagus. Except for raft-forming alginates. A study concluded that raft-forming alginates are effective in inhibiting pepsin activity . They can also remove multiple bile acids from the refluxate. The study concluded that the “raft” was capable of neutralizing many such reflux aggressors.

Natural Sources of Raft-forming Alginates

Raft forming alginates for Acid Reflux

Raft forming alginates for Acid Reflux

Commercially, alginate is derived from algae like Macrocystis pyrifera (giant kelp) and Ascophyllum nodosum. Raft-forming alginate-antacid preparations have been available since the last 45 years. Gaviscon® is an example of such a preparation. Alginate is available as a chewable tablet or as a liquid preparation.

How Much Of Raft-Forming Alginates Help In Acid Reflux?
2-4 tablets chewed 4 times a day or 2-4 teaspoonful of liquid taken 4 times a day after meals and at bedtime. Follow it with a glass of water.

Are Raft-Forming Alginates Safe?

A clinical study done to assess the safety of raft-forming alginate-antacid preparation in pregnant women shows it to be safe and effective in treating heartburn. No side effects have been reported so far. However, just like any antacid preparation, it is better to use them intermittently to relieve symptoms. You should always focus on treating the problem of acid reflux at its root.

Raft-forming Alginates – Final Verdict

The physical barrier produced by the alginates remains intact for several hours on end, providing long-term relief from acid reflux. Studies suggest that it is safe for pregnant women. It can be safely assumed that it is safe (in recommended dosages) for the general population as well. To conclude, raft-forming alginates provide an effective alternative to conventional antacids that either stop acid production/secretion or neutralize gastric acidity.

Jitendra Rathod
Jitendra is a microbiologist and a passionate student of the human body. He is a firm believer in the power of alternative and holistic medicine. He believes nature holds the key to restore us back to health and balance.


Post-prandial reflux suppression by a raft-forming alginate (Gaviscon Advance) compared to a simple antacid documented by magnetic resonance imaging and pH-impedance monitoring: mechanistic assessment in healthy volunteers and randomised, controlled, double-blind study in reflux patients

An Alginate-Antacid Formulation Localizes to the Acid Pocket to Reduce Acid Reflux in Patients With Gastroesophageal Reflux Disease

Assessment of the Safety and Efficacy of a Raft-Forming Alginate Reflux Suppressant (Liquid Gaviscon) for the Treatment of Heartburn during Pregnancy