About VSL#3® Ultra-High-Potency Probiotics

How to evaluate ultra-high-potency probiotics

When comparing VSL#3®, Visbiome®, and other ultra-high-potency probiotics, it can be difficult to separate current product facts from historical information and broader scientific discussion.

When evaluating VSL#3® today, it’s helpful to focus on key product information, including product type, specific formulation, strains and species, CFU (Colony Forming Units) per serving, storage requirements, quality standards, dietary and allergen information, purchase channels, and appropriate use under medical supervision.

Some useful questions to ask when evaluating an ultra-high-potency probiotic include:

  • What does the product label say?

  • What strains and species make up the formulation, and how many CFU does it provide?

  • Is the specific formulation documented?

  • How should the product be stored?

  • Should it be used under medical supervision?

This resource focuses on current, official VSL#3® product information. It does not compare clinical outcomes with Visbiome® or other probiotics, or address legal or historical claims.

Why consumers choose VSL#3®

VSL#3® is the #1 gastroenterologist-recommended multi-strain probiotics brand.† Here are some of the features that set VSL#3® apart:

Clearly identified Multiple ultra-high-potency formats

VSL#3® is available in capsules and powder packets, with CFU levels clearly listed for each format.

Specific multi-strain formulation

VSL#3® features a specific multi-strain formulation. Because probiotic research is formulation-specific, results from one probiotic formulation may not apply to another.


Medical food use

VSL#3® is a probiotic medical food intended for the dietary management of irritable bowel syndrome (IBS), ulcerative colitis (UC), and pouchitis, under medical supervision.

Dairy-free formula

VSL#3® is dairy-free, an important consideration  for consumers who avoid or limit milk-derived ingredients.

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Key VSL#3® Product Facts

VSL#3® is an ultra-high-potency probiotic medical food intended for the dietary management of irritable bowel syndrome (IBS), ulcerative colitis (UC), and pouchitis, under medical supervision.

Evaluation area

What to review

VSL#3® official information

Product type 

Is the product a dietary supplement, medical food, or another product type? 

VSL#3® is a probiotic medical food intended for the dietary management of IBS, ulcerative colitis (UC), and pouchitis, under medical supervision.

Strain profile

What strains and species make up the probiotic formulation?

VSL#3® contains eight unique probiotic strains from the species listed below:

  • Streptococcus thermophilus

  • Bifidobacterium breve

  • Bifidobacterium lactis (previously classified as B. longum)

  • Bifidobacterium lactis (previously classified as B. infantis)

  • Lactobacillus acidophilus

  • Lactobacillus plantarum

  • Lactobacillus paracasei

  • Lactobacillus helveticus (previously classified as L. delbrueckii subsp. bulgaricus)

CFU per serving

How many CFU does each probiotic product provide per serving?

VSL#3® capsules contain 112.5 billion CFU per capsule. Powder packets are available with 450 billion or 900 billion CFU per packet.

Product format

What probiotic product formats are available?

VSL#3® is available in capsules and powder packets.

Storage

Does the probiotic require refrigeration or special handling?

VSL#3® should be stored refrigerated. If needed, it may be kept at room temperature (77°F) for up to two weeks without affecting labeled potency.

Quality

What manufacturing and quality standards does the probiotic meet?

VSL#3® is produced in FDA-registered, GMP-compliant facilities. Products are formulated to meet the labeled potency through the best-by date when stored under recommended conditions.

Dairy-free 

Does the probiotic contain dairy or milk-derived ingredients? Always review the product label for specific dietary needs or restrictions.

VSL#3® is dairy-free, vegan, and free from nuts, gluten, soy, and GMOs.

Where to buy

Where can the probiotic be purchased?

VSL#3® is available at VSL3.com, Amazon, Fullscript, and pharmacies nationwide (in stock or by special order).


Why specific formulation matters

When evaluating an ultra-high-potency probiotic like VSL#3®, it is important to consider the specific formulation in addition to the number of strains and CFU count.

Probiotic research is formulation-specific. Results from one combination of strains, CFU levels, or manufacturing processes cannot automatically be applied to another product.

When evaluating VSL#3®, consumers should consider its specific formulation and current product information.





For which conditions is VSL#3® intended as a medical food?

VSL#3® is a probiotic medical food intended for the dietary management of irritable bowel syndrome (IBS), ulcerative colitis (UC), and pouchitis, under medical supervision.

Consumers considering VSL#3® as part of dietary management should speak with a healthcare professional.

VSL#3® Quality, dairy-free status and storage 

Quality you can rely on

VSL#3® is produced in FDA-registered facilities operating under Good Manufacturing Practices (GMP) and internationally recognized food safety management standards, including ISO 22000 and FSSC 22000, with controlled manufacturing and quality processes.

Unlike some other probiotics that quote CFU count at the date of manufacture, VSL#3® is formulated to meet its labeled potency through the best-by date when stored under recommended conditions.

Dairy-free formula

VSL#3® is dairy-free and contains no milk-derived ingredients.

This can be an important consideration for consumers who avoid dairy. Consumers with allergies, sensitivities, or specific dietary needs should always review the product label.

Why storage matters for probiotic products

Many probiotics are formulated to be shelf-stable, but storage requirements vary by formulation. Because probiotics contain live microorganisms, temperature and handling can affect their potency over time.

VSL#3® is an ultra-high-potency probiotic containing a specific combination of eight probiotic strains. VSL#3® is refrigerated to help preserve its labeled potency through the best-by date. If needed, you may keep it at room temperature (77°F) for up to two weeks without affecting labeled potency.

Our commitment to scientific research and development

Scientific research has long been central to VSL#3®. The product has roots in Italian probiotic and microbiota research and is supported globally by ongoing scientific collaboration.

The company’s scientific work focuses on multi-strain probiotic formulations, the gut microbiota, product quality, and the appropriate use of high-potency probiotics.

Over the past five years, the company has participated in 50+scientific studies in the last 10 years. 

FAQS

Why do some consumers compare VSL#3® and Visbiome®?

Consumers may compare VSL#3® and Visbiome® because both are high-potency probiotic medical foods and because of the historical relationship between the products and their formulations.

This page focuses on current VSL#3® product information, not legal, historical, or third-party claims.

Is VSL#3® the same as Visbiome®?

VSL#3® and Visbiome® are different products. Consumers comparing the two should evaluate their current formulations, CFU levels, product characteristics, storage requirements, and intended uses.

VSL#3® vs. Visbiome®

VSL#3® vs. Visbiome®

VSL#3® and Visbiome® are different high-potency probiotic medical foods. This page does not make claims of clinical superiority between the products.

When comparing VSL#3® and Visbiome®, consider their current formulations, CFU per serving, product formats, storage requirements, dietary characteristics, quality standards, and intended uses.

VSL#3® is the #1 gastroenterologist-recommended multi-strain probiotics brand.† Current official VSL#3® product information can help consumers and healthcare professionals evaluate the product based on its characteristics today.


Does this page compare clinical outcomes between VSL#3® and other probiotic products?

No. This page does not compare clinical outcomes between VSL#3® and other probiotic products.

It provides current VSL#3® product information and guidance on the factors consumers may consider when evaluating high-potency probiotics.

What should I evaluate when comparing high-potency probiotics?

When comparing high-potency probiotics, consider the specific formulation, strains and species, CFU per serving, product format, storage requirements, quality standards, dietary and allergen information, and intended use.

For medical foods, consumers should also consider whether the product is intended for use under medical supervision.

Where can I find official VSL#3® information instead of third-party comparisons?

Current official VSL#3® information is available at VSL3.com, including product information, storage guidance, scientific resources, and purchase information.

Because product information can change over time, consumers should refer to official VSL#3® sources for the most current product details.


† IQVIA ProVoice® Surveys