Peptest – A Reliable Test for LPR?


Peptest is a pepsin test that allows for detection of pepsin in the mouth. It is quite a simple test where you test the saliva in your mouth for pepsin. Someone who has LPR (Laryngopharyngeal Reflux) will likely have pepsin in their saliva so it’s a somewhat reliable way to test if you have LPR.

What is Pepsin and Why Do We Need to Test for it?

The first thing I want to talk about in this article is pepsin. It’s important to cover because that’s what peptest tests for.

If you didn’t know pepsin is a digestive enzyme produced in the stomach that is used to help break down and digest proteins in the stomach. The thing is when someone with LPR has problems this is usually caused by the effects of pepsin. The reason is because the pepsin basically tries to digest the throat etc when it refluxes up. This means the throat can be inflamed and irritated because of this pepsin.

As you might have imagined often when someone has these symptoms in the throat because of the pepsin this means the pepsin will often make its way into the mouth even in very small amounts and this is where peptest comes in.

Diagnosing LPR with Peptest

Peptest is really a very simple test to perform and get access to in the first place. It’s just a matter of ordering the test kit where you can easily do it from home. 

Once you have ordered the test kit it will be sent to your address. Once it has arrived basically all you do is add salvia to the tube at different points. Once you have done this you will then send the tubes which will be tested by RD Biomed. After a couple of days the salvia will be tested and the results will be sent to you. If your result is positive you will be provided the concentration of pepsin which you can then learn from. 

The important thing to mention is usually only someone who has LPR will have pepsin in their salvia so it’s a relatively useful LPR test from that point of view. Because people who don’t have that kind of acid reflux won’t have the pepsin present in their salvia.

Alternatives Ways to Test for LPR

There are multiple ways to test for LPR some of which are much more reliable than others. The best singular test for LPR is arguably a test called Restech pH study or sometimes called Dx-pH. This test is where they put a fine tube up your nose and down your throat and esophagus and leave it there typically for 24 hours. 

During that 24 hours it measures the acid levels of the esophagus and up into the throat and larynx area. This test may seem very similar to a typical pH monitoring test but the important thing to mention that this test uses a different sensor which is much better at detecting gaseous acid reflux which is the primary cause of LPR. Now let me talk about the standard pH monitoring tests which a lot of doctors may typically send you for.

With the common pH monitoring test it functions the same was that the Restech pH study does. The main difference is the sensor it uses it made for detecting liquid reflux which is typical for GERD patients but not LPR patients. That means for people with LPR this test can be highly inaccurate and really is not a good way to test for LPR at all – this is because LPR is primarily gaseous reflux and the probe used for this test is not very sensitive to that.

There are other ways which can be helpful for detecting the cause of the problem but usually are not used for actual diagnosis of having the problem. As an example we have the endoscopy which can be useful at detecting the root cause of LPR such as a loose LES or malfunctioning UES for example but for actually diagnosing LPR it’s of no use. For more information on causes check out my complete guide to LPR.

One final way to help diagnose LPR is by doing a test called the RSI test which stands for reflux symptom index. This isn’t a traditional medical test but instead a test based on your symptoms which you can easily take on my website here – RSI test. It’s based on your symptoms and based on your score is quite a reliable measure for diagnosing if you have LPR.

Before You Do the Peptest

Stopping Gaviscon (etc)

There are a couple of important things worth mentioning before you do the peptest. You should stop any raft foaming antacid – this is usually things like Gaviscon. Medications for example PPIs like omeprazole and H2As like ranitidine can be taken as normal because they won’t affect the pepsin.

Stopping Alkaline Water

The second thing worth mentioning is to stop drinking alkaline water. There has been studies which show that drinking alkaline water which a pH over 8 basically deactivates the pepsin in the throat. So if you are drinking it that could affect the test results. You can read more about alkaline waters effect on LPR here.

Pros & Cons of Peptest


  • Cheaper and more affordable than other tests
  • Can easily be done from home
  • Easy for anyone to do
  • Not uncomfortable to do unlike other tests
  • Somewhat good indication of LPR


  • Not recognised/understood by most doctors
  • Not a definitive diagnosis
  • Somewhat hard to understand results

Frequently Asked Questions

Does Peptest Work?

Peptest is a relatively effective way for helping to diagnose LPR though for traditional acid reflux like GERD it is not the optimal testing option.

What is a Pep Test?

A pep test is a pepsin test which where you simply put your salvia in a test tube and then it’s sent to the lab to be tested for pepsin. Having pepsin present in your saliva is a good indicator that you might have LPR which is sometimes called silent reflux.

Is Pepsin Found in Saliva?

Typically for the normal person pepsin will not be found in your saliva. Therefore someone who has pepsin present in their saliva shows a higher likelihood of that person having LPR.

How Do You Know if You Have LPR?

Usually people who have LPR have symptoms primarily around the larynx and throat area, though it is not limited to that. Symptoms can also be had in the ears and sinuses etc. The easiest way to know if you have LPR is based on these symptoms. If you take the RSI (reflux symptom index) test and score over a certain score this is a quick and easy way to know if you have LPR. You can find the RSI test here.

What To Avoid if You Have LPR?

When it comes to diet there are a host of things you will likely want to avoid. The first obvious things are the triggers foods/drinks such as alcohol, spicy food, chocolate etc – for a more complete list check out – LPR foods to avoid. Ideally it’s best to avoid foods and drinks with a pH of less than 5 to see the best results. For getting started check out this – LPR Diet and also for a complete and in depth diet for people with LPR check out the Wipeout Diet.

Related Posts – 

LPR Treatment

LPR Symptoms

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