Is "Oral GLP-1" a Substitute for Injections? 3% Weight Loss in 8 Weeks, Examining the Popular "Postbiotics"

"Slimming Injections" Have Significantly Changed the Norms of Obesity Treatment.

With the introduction of semaglutide, known as the active ingredient in Wegovy and Ozempic, and tirzepatide used in Mounjaro, obesity is now widely recognized not merely as an issue of "weak willpower" but as a condition that can be treated by regulating appetite and metabolism through hormones.

At the center of this is GLP-1.

It is one of the hormones secreted from the intestines when eating, which signals the brain to feel full and works to suppress appetite. GLP-1 receptor agonists have achieved significant weight loss effects by utilizing this mechanism as a powerful and long-lasting pharmaceutical.

However, a new approach aiming for the next step is emerging.

Instead of stimulating GLP-1 receptors with drugs,the idea is to increase the GLP-1 secreted from one's own intestines.

The supplement called "resM GLP-1 Postbiotic" is gaining attention as a candidate for this approach.

In August 2026, the UK Daily Mail reported extensively on this supplement, suggesting it might offer weight loss effects similar to Wegovy or Mounjaro for about £1.50 a day.

It's inexpensive, comes in capsule form instead of injections, and studies have confirmed weight loss and increased GLP-1 levels.

Hearing this, one might hope, "Could this mean expensive slimming injections are no longer necessary?"

However, a closer look at the research reveals that while the results are intriguing, there is still a significant gap before concluding it is "equivalent to Wegovy or Mounjaro."

What Exactly Are "Postbiotics"?

The core of this supplement is a heat-treated strain of lactic acid bacteria called Lactiplantibacillus plantarum RSB11.

Generally, when people hear "probiotics," they imagine live lactic acid bacteria or bifidobacteria.

In contrast, postbiotics utilize the bacteria themselves, which have been heat-treated or otherwise processed, or components derived from them.

The researched resM includes this heat-treated L. plantarum RSB11, along with vitamin D3, vitamin B12, chromium, mulberry leaf extract, and fenugreek seed extract.

So, it's not as simple as "drinking a certain lactic acid bacteria will make you lose weight."

It's important to note that it is being tested as a product combining multiple components.

8-Week Clinical Trial Involving 80 Participants

The study involved 80 adults classified as overweight or obese.

Participants were randomly divided into two groups, with one group taking resM and the other taking a placebo with a similar appearance daily, and changes were observed over approximately 8 weeks.

The study was a randomized, double-blind, placebo-controlled trial.

As a supplement study, it was designed to be more reliable than simply "surveying users."

And indeed, the results were eye-catching.

In the group that took resM, there was an average weight loss of about 2.6 kg, approximately 3.0% of the initial body weight.

In contrast, the placebo group saw an average weight gain of about 0.5 kg, approximately 0.6%.

Researchers also investigated "strong cravings for food."

In the resM group, scores on questionnaires evaluating food cravings decreased.

Particularly noteworthy this time was the active GLP-1.

The study reported that the blood levels of active GLP-1 significantly increased, approximately doubling in the resM group.

Not only weight but also indicators related to the "desire to eat" and GLP-1 both changed.

This has led to expectations for a new weight loss method that can be called "oral GLP-1."

Why Are Gut Bacteria Related to "Appetite"?

The human gut is not merely a digestive tract.

It contains a vast number of bacteria, and their metabolites are found to be related to immunity, blood sugar, inflammation, and even the brain and appetite.

GLP-1 is also part of this.

When food enters the intestines, hormones like GLP-1 are released from cells in the intestinal tract.

Research is being conducted on how gut bacteria and the metabolites they produce might influence this mechanism.

Thus, the current idea is

"to directly stimulate GLP-1 receptors with drugs"

rather than

"to utilize the gut environment to promote one's own GLP-1 secretion."

There is a significant difference here.

"Even if GLP-1 Doubles," It Doesn't Mean It's Half of Wegovy

When this type of research becomes a topic on social media, numbers alone tend to take on a life of their own.

For example, seeing the result "GLP-1 doubled," some might think, "Doesn't that mean it's the same as GLP-1 drugs?"

However, such a comparison cannot be made.

Wegovy's semaglutide is not a drug that increases the GLP-1 produced by humans.

It is a pharmaceutical designed to administer molecules with similar effects to GLP-1, stimulating GLP-1 receptors for an extended period.

In contrast, what was measured this time was the blood concentration of active GLP-1 produced within the human body.

While the figure "GLP-1 doubled" is intriguing, it cannot be concluded from this alone that "the same efficacy as Wegovy can be obtained."

The strength of the effect, duration, and movement within the body are all different.

So, Can It Really Lead to Weight Loss Comparable to Wegovy?

Here, it is necessary to separate the headline of the original article from the actual scientific data.

In the representative STEP 1 trial that examined 2.4 mg of semaglutide, the active ingredient in Wegovy, 1,961 people were followed for 68 weeks.

As a result, the average weight loss rate in the semaglutide group was 14.9%.

Furthermore, in the SURMOUNT-1 trial conducted on tirzepatide, used in Mounjaro, 2,539 people were followed for 72 weeks.

Depending on the dosage, an average weight loss of about 15-21% was reported.

In contrast, resM involved 80 people, with about a 3% reduction over 8 weeks.

There is no need to dismiss the 3% figure as small.

If an average of 2.6 kg was lost in just about two months, there is enough value to pursue further research.

However, directly comparing an 8-week trial with 80 participants to pharmaceutical trials that tracked thousands of people for over a year and concluding "it leads to similar weight loss" is unreasonable.

Will weight loss continue after 8 weeks?

What about six months later?

What about a year later?

Will the weight return if intake is stopped?

These are unknown at this point.

Research on "L. plantarum and Weight Loss" Has Existed Before

The current results are not entirely unprecedented.

The relationship between Lactiplantibacillus plantarum and obesity or body fat has been studied before.

For example, in a randomized trial with about 100 people using another strain, LMT1-48, weight loss and changes in abdominal visceral fat were observed after 12 weeks in the intake group.

Another study using L. plantarum IMC 510 also investigated effects on weight, BMI, waist circumference, blood sugar, and gut bacteria in overweight and obese individuals.

Furthermore, in Japan, a randomized trial with about 100 people using yogurt containing heat-treated L. plantarum OLL2712 reported effects on abdominal fat accumulation.

In other words,

there is a certain accumulation in the research field of "utilizing components derived from lactic acid bacteria to influence metabolism."

However, with lactic acid bacteria, the "strain" is very important.

It does not mean that buying a commercial supplement labeled L. plantarum will yield the same effect as this study.

"Can I Just Buy the Same Bacteria at a Health Food Store?" Reader Comments Respond

The Daily Mail article received numerous comments.

Among them, some focused on the Lactiplantibacillus plantarum used in the study, with reactions suggesting it could be purchased at health food stores.

On the other hand, more prominent were voices questioning the independence of the research.

Some readers pointed out that "the research is supported by a supplement company" and did not take the results at face value.

Additionally, the traditional opinion that "ultimately, diet and exercise are fundamental" garnered strong support.

These reactions symbolize the current diet market.

Consumers no longer unconditionally jump at promotional phrases like "lose weight just by taking it" or "natural, so it's safe."

Especially with more people experiencing significant weight loss through GLP-1 drugs, the focus has shifted to "how long and to what extent can it be maintained" rather than just "a few kilograms lost."

The Repeated Concern on SNS: "Food Noise Returned"

Regarding resM itself, it is difficult to say that a large independent user community or a plethora of SNS reviews have formed at this point.

However, looking at communities of GLP-1 drug users on platforms like Reddit reveals why new supplements attract attention.

The term "food noise" frequently appears.

Literally translated, it means "food noise."

It refers to a state where, even when not hungry, one keeps thinking about what to eat next, can't get food off their mind, or continues to have urges to snack.

Among those using GLP-1 drugs, some report that this food noise significantly decreased.

However, posts also appear where, after stopping the medication, people complain that "the feeling of hunger returned," "I started thinking about food all the time," and "I can't suppress my appetite like before."

In 2026, a user posted on Reddit's GLP-1 drug discontinuation weight maintenance community about their anxiety after abruptly stopping the medication due to insurance issues, experiencing a return of strong hunger and food cravings, and beginning to gain weight in a short period.

In the comments, methods to enhance satiety using dietary fiber and ways to review meal content were also discussed as alternatives to medication.

This does not prove the effectiveness of resM.

However, it is clear that there is a strong demand for **"ways to control appetite other than continuing GLP-1 drugs indefinitely."**

The Realistic Issue of "Continuing Expensive Medication for Life"

While GLP-1 drugs are achieving significant results, there are issues separate from their effectiveness.

The cost.

Depending on the country and insurance system, the burden varies greatly, but posts on social media frequently mention the end of insurance coverage, high out-of-pocket costs, and the difficulty of paying over a long period.

That's why a supplement that costs "a few hundred yen a day" and "doesn't require injections" appears attractive.

Even if the weight loss effect is weaker than pharmaceuticals,

it could be meaningful for

"people who don't need medication,"

"people who are resistant to injections,"

"people who want to maintain weight after stopping GLP-1 drugs."

In the future, it might become an option to "fill the gap between medications" rather than a "replacement for medication."

However, this is a hypothesis that should be verified through future research and is not an established use at this stage.

Caution Needed with the Term "No Side Effects"

In this study, no serious adverse events were reported, and blood tests to examine safety did not indicate major issues.

This is a positive aspect.

On the other hand, Wegovy and tirzepatide are relatively well-known for gastrointestinal symptoms such as nausea, diarrhea, and vomiting.

Therefore, the point that "no major side effects were confirmed with the supplement" is indeed attractive.

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