ProbioSlim Review: Will Probiotics Help You Lose Weight?

ProbioSlim Review: Will Probiotics Help You Lose Weight?

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ProbioSlim is a weight loss supplement sold by a brand called Force Factor. The brand describes this supplement as containing "advanced weight management ingredients" as well as a trademarked compound called LactoSpore that can improve gut health.

But does ProbioSlim contain research-backed ingredients for weight loss or are these just marketing claims? Is LactoSpore actually proven to optimize gut health and reduce gastrointestinal distress? Does ProbioSlim contain any questionable additives? And how do real users rate and describe the effects of ProbioSlim?

In this article we’ll answer all of these questions and more as we analyze the ingredients in ProbioSlim based on medical studies to give our take on whether the supplement is likely to be effective for weight loss and digestive support or if it's a waste of money.

We'll also review their gummy formulation, document which retailer sells ProbioSlim for the cheapest price, and feature real, unsponsored ProbioSlim user reviews. We will explain why the manufacturer has been sued three times in recent years.

ProbioSlim Ingredient Analysis

ProbioSlim ingredients list

The ingredients in ProbioSlim are shown above.

LactoSpore is a patented version of probiotic strain Bacillus coagulans MTCC 5856.

A clinical trial published in the Journal of Chiropractic Medicine tested whether LactoSpore caused weight loss in overweight individuals.

The trial participants lost an impressive 8.6 pounds over the course of the three-week trial, but they were eating a significantly reduced-calorie diet, which alone can cause weight loss.

This is a very poorly-designed trial in our opinion. The way to prove whether LactoSpore causes weight loss would be to have two trial groups consuming the exact same diet, with one of them taking LactoSpore and the other taking placebo pills. This would isolate the effects of LactoSpore. 

Green tea extract is effective for short-term weight loss, as we documented in our analysis of Lipozene ingredients.

Papaya extract was shown in a 2019 medical review to be effective for weight loss, but the doses used in the clinical trials were higher than the dose of all ingredients in ProbioSlim combined.

While ProbioSlim has some potentially effective ingredients, it also has a few questionable ingredients.

Titanium dioxide is a colorant that was banned in the European Union (E.U.) for use as a food additive due to toxicity concerns.

And while green tea extract may be effective for short-term weight loss, it also may cause liver injury according to Health Canada. This is especially concerning in regard to supplements like ProbioSlim where the dose of green tea extract is not published.

Overall we consider ProbioSlim potentially effective for weight loss. We consider it likely effective for gut health given that probiotics are well-established in clinical research to improve the gut microbiome.

But how do real users rate it? We'll review in the next section.

Real People Try ProbioSlim

ProbioSlim is sold on Amazon, which is a better resource for honest customer reviews than a brand's website in our opinion.

The supplement has been reviewed over 5,000 times with an average review rating of 4.1 out of 5 stars. 

The top positive review from a verified purchaser comes from a user named "M.S. Grebinowski" who claims it caused weight loss:

"I switched to this probiotic because it stated it would help to shed some weight. Since I'm diabetic, I didn't want to use harsh diet pills and can't afford expensive diet plans. These helped me lose 30 lbs. before my surgery, and I'm keeping it off."

The top negative review from a verified purchaser is written by a user named "Cody" who claims it caused side effects:

"Made me too jittery would not recommend."

A video from YouTube creator "Magnolia's World" is one of the few unsponsored reviews of ProbioSlim we could find:

ProbioSlim Gummies Ingredient Analysis

ProbioSlim Gummies ingredients

ProbioSlim also comes in an apple cider vinegar gummies version which we consider to have a worse formulation than the original. 

LactoSpore is included at a much lower dose, and the "Super Fruit" blend dosages are comically low.

The dose of each "Super Fruit" ingredient is 100 micrograms (mcg). According to the USDA, one single grape has a dose of 4.9 grams (g), which equals 4,900,000 mcg.

This means that one single grape has a dose 49,000 times higher than the "Super Fruit" ingredients in ProbioSlim gummies. 

Apple cider vinegar (ACV) is included at a dose of 500 mg. As we documented in our review of keto gummies, the effective dose of ACV for weight loss appears to be around 15,000 mg according to clinical studies, or 30x the amount in this supplement.

ProbioSlim Apple Cider Vinegar Gummies contain more questionable additive ingredients than the capsule formulation.

Added sugar can contribute to obesity and cardiovascular disease when consumed in excess according to medical research, and it seems illogical to include added sugar in a weight loss formulation.

Citric acid can cause whole-body inflammation when it's manufactured from a fungus, which is the case over 90% of the time in food processing according to a medical review published in the Toxicology Reports journal.

Natural flavor is a broad categorical term that fails to describe the specific flavoring agents used. Without this information, we cannot assess the safety of this ingredient.

Where to Get the Best Price

ProbioSlim is sold at a variety of online retailers. Here's a price breakdown at the time of updating this article:

Target: $13.77 (link)

Walmart: $11.21 (plus shipping, link)

iHerb: $4.84 (plus shipping, link)

Amazon: $4.84 (free shippinglink to official Amazon listing)

ProbioSlim is currently 65% cheaper at Amazon than at Target.

$4.84 with free shipping is the cheapest weight loss supplement we've ever reviewed on Illuminate Health.

Why Was Force Factor Sued?

Force Factor has been sued multiple times.

In 2014, the brand was sued over claims that one of their supplements boosts testosterone levels, according to the Boston Business Journal. The lawsuit alleged those claims to be misleading.

In 2018, Force Factor was sued in a class-action lawsuit related to their BCAA supplement, according to Truth in Advertising. The brand had claimed that the active ingredient in this supplement increased muscle synthesis, and the plaintiffs alleged that scientific evidence proves that the supplement actually decreases muscle synthesis.

In 2020, Force Factor settled a lawsuit with the Federal Trade Commission (FTC) for over $1 million, according to Legal Newsline. The lawsuit alleged that the company was using deceptive marketing practices and hiding the true deadline of cancelling a free trial, and Force Factor is now banned from using negative option marketing.

We recommend that consumers be wary buying from supplement brands with so many legal actions taken against them, especially from governmental organizations.

Questionable Health Claims on ProbioSlim Site

There are a number of questionable and uncited health claims on the two ProbioSlim product pages.

On the ACV gummies page, the manufacturer claims that one dose contains as much acetic acid as one tablespoon of ACV:

ProbioSlim questionable health claim 1

Acetic acid is the active chemical component in ACV that's thought to cause its weight loss effects. However, this dosage claim appears to be inaccurate. 

According to Bragg, one of the largest ACV manufacturers, one tablespoon of ACV contains 750 mg of acetic acid. Force Factor's gummies contain only 25 mg of acetic acid, or 30x less than what they're claiming in this sales pitch.

The same product page claims that "super fruits" in the formulation "support healthy digestion." We certainly haven't seen any clinical studies suggesting that fruit dosed at 0.002% of one single grape supports digestion, and this claim is not cited.

ProbioSlim questionable health claim 2

On the ProbioSlim capsule product page, the brand claims that the supplement will boost energy and vitality without any medical citations or proof for this claim.

Our Clean Weight Loss Picks

There are food-based nutrients which have been shown in medical studies to be effective for weight loss.

Dietary fiber was shown in a medical review published in The Journal of Nutrition to cause 16 pounds of weight loss in 6 months when combined with moderate caloric restriction (750 calories per day below baseline).

MBG Organic Fiber Potency+ is our top fiber pick because it's certified organic, provides 7 g of fiber per serving and costs under $1.85 per serving at the time of updating this article.

MCT oil was shown in a meta-study to cause more than one pound of weight loss over 10 weeks. This equates to potential annualized weight loss of 6 pounds per year with less than one tablespoon's worth of MCT oil per day.

Bulletproof MCT Oil is our top MCT oil product, because the only ingredient is MCT oil derived from coconuts. and it currently costs only $15.50 for over a month's worth of product.

Ginger intake "significantly decreased body weight" according to a 2019 meta-study on ginger and weight loss that analyzed data from 14 clinical trials.

Pique La Ginger is our top ginger product, because it's an organic tea in convenient crystallized form, and all that's needed is to pour the powder into a glass and add hot water.

All three of the products mentioned in this section are entirely free of additive ingredients that we consider to be unhealthy.

Pros and Cons of ProbioSlim

Here are the pros and cons of ProbioSlim in our opinion:


  • Highly affordable
  • Some research-backed ingredients
  • Generally positive customer reviews


  • Manufacturer has been sued 3x in last decade
  • Contains green tea extract
  • Brand makes questionable health claims
  • Both formulations contain questionable additives
  • Gummy supplement very poorly formulated for weight loss
Stay up-to-date on our research reviews


We don't currently recommend either ProbioSlim capsules or gummies.

The capsule formulation contains some effective ingredients, but it includes green tea extract without an ingredient dose which is concerning to us given the documented risk of liver injury with high dosage intake of green tea extract. This formulation also contains titanium dioxide which is an ingredient we recommend consumers avoid.

The gummy formulation contains one effective active ingredient that appears to be vastly underdosed, and several questionable additive ingredients including added sugar, which is a strange choice for a weight loss supplement.

Force Factor, the manufacturer of ProbioSlim, has been sued three times in the past decade and recently settled with the FTC over allegations of deceptive marketing practices. The brand is banned from a specific type of marketing, which is a red flag in our opinion.

There are a number of questionable and uncited health claims on the ProbioSlim website, including an assertion that their gummies provide the same acetic acid content as a tablespoon of ACV, while their gummies appear to provide 30x less acetic acid content.

For consumers intent on purchasing ProbioSlim, we recommend doing so on Amazon where it's currently cheaper than any other retailer and 75% cheaper than at GNC.