Are There Prescription Probiotics?

In our latest question and answer, our pharmacist discusses whether or not prescription probiotics are available.

Dec 06, 2017

jennifer asked

Hello, Doing some research regarding probiotics and digestive enzymes for pt.s with IBS. Wondering if there are any prescription probiotics to have the Dr. I work with prescribe for our patients? Thank you!


Unfortunately, the evidence available only suggests a possible utility for probiotic supplements in the management of IBS. A more thoroughly researched intervention to explore instead would be the low FODMAP diet. I’ve included a link to an excellent article summarizing the research on this topic for you to review.

IBS, as you may know, is a complex and stubborn condition. The data available on using probiotics to manage IBS are just too inconclusive for me to be comfortable suggesting that any probiotic product or strain might be consistently beneficial to these patients.

At the time of this writing, there are no prescription-only probiotic supplements in the US. Probiotic supplements are considered dietary supplements, and are available for purchase without a prescription. While any physician can certainly write a script for a dietary supplement or over-the-counter drug, this doesn’t affect whether it will be covered by insurance. In the case of probiotic supplements, it likely will not be.

As a healthcare professional, and seasoned scientific skeptic, I strongly caution you to avoid relying on general internet research on this topic to support the use of any specific probiotic product. After the research I did on this question, the only thing clear to me was that the search results are rife with slick marketing copy and advertisements cleverly disguised as professional medical opinion or independent study results. Even to the trained and experienced eye, this stuff looks like legit science coming from legit labs or consumer protection organizations, when in fact it’s often paid for by a company trying to bolster its claims on the products it sells.

If this physician is not a GI specialist and wants to help his or her patients with IBS, I would recommend consulting with a GI or dietary specialist to learn more about the low FODMAP diet, which is often a first recommendation for management of IBS symptoms. The efficacy of this intervention is substantiated by high-quality medical research, and moreover, does not involve the sale or purchase of any product to use. That’s something both a physician and a patient can appreciate! Thanks for your question!

Medical Food Probiotics

While there are no prescription probiotics (beside from one exception discussed below), there is a medical food probiotic known as VSL #3. 

Medical foods, in regard to regulation, exist in-between dietary supplements and FDA approved prescription medication. According to the FDA:

"Food which is formulated to be consumed or administered enterally under the supervision of a physician and which is intended for the specific dietary management of a disease or condition for which distinctive nutritional requirements, based on recognized scientific principles, are established by medical evaluation"

In other words, for a product to be considered a medical food, it must meet the following criteria:

  • Be specifically formulated for oral or tube feeding
  • Be labeled for the dietary management of a specific medical disorder, disease, or condition with specific nutritional requirements
  • Be intended for use under medical supervision

Perhaps most importantly, medical foods can claim to help a particular disease by providing nutrients that are not or cannot be met by ordinary foods. This is an important difference from dietary supplements, which cannot claim to treat a specific disease. For example:

  • Glucosamine/chondroitin dietary supplements are often labeled to be used for "joint health," but not "for arthritis." A medial food on the other hand, could be labeled "for arthritis."

While most medical food products are "prescription only",  the prescription status of a medical food is actually at the discretion of the manufacturer and not all medical foods require a prescription. VSL #3 is a good example of a medical food that does not require a prescription (however, the double strength version of VSL #3, "VSL #3 DS", does require one).

Before discussing VSL #3 specifically, it is important to note that medical foods can state health claims that have not been evaluated by the FDA and there is no FDA review or approval process for medical foods. For further information on medical foods, the FDA has published a FAQ on their website.

VSL #3

VSL #3 contains numerous bacterial cultures including:

  • Lactobacillus acidophilus
  • L. plantarum,
  • L. paracasei
  • L. bulgaricus
  • Bifidobacterium breve
  • B. infantis
  • B. longum
  • Streptococcus thermophilus

There are:

  • 450 billion live bacteria in each regular packet
  • 225 billion live bacteria in 2 capsules
  • 900 billion live bacteria in each DS (double strength) packet

VSL #3 is labeled for the dietary management of:

  • Ulcerative colitis
  • Irritable bowel syndrome
  • Ileal pouch

While there isn't an abundance of data, studies suggest that VSL #3 may be effective for achieving remission in those with active ulcerative colitis. Studies also show positive evidence for diarrhea predominant irritable bowel disease.

It is important to remember that VSL #3, while a medical food, does not require a prescription and may be purchased over the counter (except for the double strength version). Nevertheless, since it is a medical food, it should be used under the supervision of a doctor.


Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date.

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