How Long Does It Take for Probiotics to Work?

If you’ve read up about the benefits of probiotics, know all about why you should have a healthy microbiome, and have finally bit the bullet and purchased a month’s supply of probiotic supplements, you may wonder when exactly they should start working.

This is a valid question that many people have, as you can’t easily tell what your little gut bugs are up to inside your intestinal tract.

In this article, we’ll answer this question the best we can (annoyingly, the short answer is that it can depend on your individual circumstances). But if you have digestive problems, you’ll probably notice the benefits sooner than someone using probiotic supplements to support other areas of health—let’s dive into the details.

How Long Does It Take for Probiotics to Work?

Depending on your health status, you may experience benefits from probiotics in as little as a few days or as long as a few months.

You will likely see benefits quicker if you take probiotics to correct digestive or gut health issues like constipation, diarrhea, stomach pain, gas, or bloating. 

Conversely, if your stomach and digestion are already in tip-top shape and you’re taking probiotics to support heart health, mood, or another area of health, it may take longer to see any improvements.

For example, one study found that combining probiotics with rehydration therapy reduced the duration and frequency of infectious diarrhea in a mere two days.

Another study of IBS (irritable bowel syndrome) patients found that supplementing with the probiotic Saccharomyces boulardii improved IBS symptoms within four weeks.

When it comes to correcting microbial imbalances (known as dysbiosis), most studies use a trial period of one month or more. Research shows that one month is sufficient to correct dysbiosis and populate the gut with healthier microbes. 

However, that does not necessarily mean that noticeable health benefits are coming simultaneously. Your gut microbiome might be getting healthier, but it still can take time to see results.

Top Signs Probiotics Are Working

The most prominent and immediate signs that a probiotic is working are related to digestion and gut health. Within days or weeks, you may experience improvements in:

• Gas
• Bloating
• Constipation
• Improved bowel movements (frequency and consistency)
• Diarrhea
• Stomach pain

This is because the probiotics are starting to flourish and thrive (in an ideal situation), creating a healthy gut microbiome. This also includes reducing dysbiosis—a buildup of harmful bacteria with insufficient good gut flora.

Over time—in the weeks-to-months range—you may experience non-digestive-related benefits from taking probiotics. 

Although the results can vary widely, some potential benefits over months-long periods may include:

• Improved sleep
• Reduced stress, anxiety, and depression
• Better mood and mental clarity
• Improved cardiovascular or metabolic markers, like blood pressure, blood sugar, or cholesterol numbers
• Fewer vaginal, yeast, or urinary tract infections
• Better immune system health, including fewer allergies and respiratory infections
• Improvements to inflammatory skin conditions, like acne, psoriasis, or eczema
• Improvements to nonalcoholic fatty liver disease 

For a list of conditions that probiotics have been shown to help clinically, check out this list from The World Gastroenterology Organization Global Guidelines, which includes specific strains of probiotics and recommended doses.

It’s generally recommended to take a probiotic supplement for 6 to 8 weeks before assuming it doesn’t work for you. After that, take a look at the following section and see if any of these apply to you and your probiotic regimen.

Why Is My Probiotic Not Working?

There are many potential reasons why your probiotic is not working.

As a quick aside, you may not notice physical or mental health benefits, but that does not mean that you don’t have a healthier microbiome that is improving your health in other ways. The only way to really know how a probiotic is affecting your gut microbiome is if you did stool testing before and after taking it. 

That said, here are some reasons why your probiotic may not be working:

• The dose is too low (not enough CFUs, or colony-forming units). Generally speaking, probiotics containing 5 billion CFUs or more are more likely to be effective than lower doses for treating digestive issues. 
• Too few bacterial strains or taking the wrong probiotic strain for your health condition. Certain probiotic strains are best for specific health disorders. 
• You aren’t taking it correctly (taking just one capsule versus the recommended two or taking it after a big meal when the manufacturer recommends it on an empty stomach, for example).
• The probiotic supplement did not take into consideration survivability. As probiotic bacteria need to survive the harsh environment of stomach acid to make it into your colon, probiotic brands should show that their strains are able to survive the journey (which typically involves delivery systems like specialized capsules). 
• They were stored improperly. Heat, light, and humidity can all affect probiotics negatively, and some require refrigeration.  

What Are the Best Probiotic Supplements?

The probiotics you take can vary depending on your health situation or goals. Some of the best probiotic supplements for different uses can be found in these articles: Best Probiotics for Men and Best Probiotics for Women.

Here are a few of our top favorites for women looking for probiotic supplementation: 

• WiseHuman Women’s Daily Probiotic: With 20 billion CFUs (colony-forming units) of probiotics and prebiotics, this supplement is designed to support digestive, vaginal, and immune system health.
• Garden of Life Dr. Formulated Once Daily Probiotic: This probiotic supplement has 50 billion CFUs of beneficial bacteria made up of 16 probiotics, including Lactobacillus reuteri and Lactobacillus fermentum, two documented probiotic species for women’s health. 
• Nordic Naturals Flora Probiotic Daily: This supplement contains 12 billion CFUs, including the first commercialized probiotic for dietary supplements, Lactobacillus acidophilus DDS-1, combined with the prebiotic fiber FOS (fructooligosaccharide) to support the gut microbiome and digestive health.

For men looking for a probiotic, try one of these:

• Ancient Nutrition SBO Probiotic Men’s: In addition to 25 billion CFUs of clinically studied soil-based probiotics, this supplement contains minerals, functional mushrooms, and superfoods like organic fermented ginger root, fenugreek seed, and fo-ti root, which have all been used for centuries to support male health. 
• Garden of Life Dr. Formulated Probiotics Once Daily Men’s: An excellent probiotic supplement formulated for men’s health with 50 billion CFUs from 15 probiotic strains.

How Long Does it Take for Probiotics to Work? FAQs