How Long Does It Take Probiotics to Work?

The question of how long it takes probiotics to work depends on the desired effect. Typically, digestive system improvements are seen in as little as 2-3 weeks, while shifts in hormones, metabolism, and body composition may require 3 months of consistent supplementation. In acute situations, results may be noticeable within a few days.

In this article we’ll discuss the typical duration for probiotics to kick in, potential side effects to watch for, and tips for choosing top-notch probiotic supplements.

Learn why adding a daily, high-quality probiotic to your regimen can offer benefits such as:

Support optimal hormone levels, including estrogen, thyroid, cortisol, and insulin.
Improved metabolism and support a healthy body composition, including reduced central adiposity or “belly fat.”
Enhanced digestion¹ by helping to balance gut bacteria.
Strengthened immune function, including by aiding in defenses against infections² and illnesses.
Improved nutrient absorption³ and utilization by supporting the integrity of the gut lining.
Reduced inflammation⁴.
Support for mental well-being due to how the gut-brain connection influences mood⁵ and cognitive function.
Regulated bowel movements⁶ with less constipation or diarrhea.
Balanced vaginal flora⁷ for women, with reduced risk of infections like yeast infections and bacterial vaginosis.

Probiotics, available in both food and supplement forms, are increasingly popular for their potential to enhance digestive health, support immune function, improve hormonal balance, aid in weight loss, and more. As more people explore the benefits of probiotics, questions arise regarding their effectiveness and the time it takes to experience their positive effects.

How Long Does It Take for Probiotics to Take Effect

While some conditions, like acute diarrhea may see improvement in as little as 5 days, other conditions, like polycystic ovarian syndrome (PCOS) and period cramps may require 3 months of consistent use. In fact, more recent studies suggest that on average, 3 months of daily probiotic use is the minimum time needed to observe benefits.

Gastrointestinal Condition	Estimated Time to Benefits	Probiotic Strains to Consider*
Acute Diarrhea	1-5 days	Bacillus coagulans, Saccharomyces boulardii, Lactobacillus reuteri
Irritable Bowel Syndrome	4-12 weeks	Saccharomyces boulardii,Lactobacillus acidophilus, L. rhamnosus, Bifidobacterium breve, B. actis, B. longum, and Streptococcus thermophilus, Bacillus coagulans
Constipation	8-12 weeks	Bifidobacterium animalis subsp. lactis, Lactobacillus acidophilus, Lactobacillus casei
Bloating	8-12 weeks	Lactobacillus acidophilus, Bifidobacterium lactis, Saccharomyces cerevisiae, Bacillus Coagulans, Bifidobacterium infantis, Lactobacillus plantarum

*There may be different strains your provider recommends based on new and emerging evidence.

How Do You Know if a Probiotic is Working?

If you've decided to spend time and money picking out a probiotic supplement to add to your routine, you're probably looking for signs that the product is actually “working” and doing what it's intended to do.

It can be tricky to determine if a probiotic is effective and the right type for your needs, especially at first because probiotics take time to start providing benefits. Additionally, outcomes can vary depending on people's health status, the specific probiotic strains they are taking, and the dosage.

Positive indicators that a probiotic is working include:

Consistent Digestive Improvements and Regularity

Look for reduced bloating, gas, and irregular bowel movements, which can indicate improvements in transit time⁸ and overall gut health.

You might notice you're experiencing more consistent, regular bowel movements without discomfort or urgency, reflecting improved gut motility and function. Your IBS symptoms might also improve, resulting in more predictable and comfortable digestion.

It is important to note that it is normal as your microbiome shifts to experience temporary gas, bloating, changes in bowel movement frequency or consistency when initiating a probiotic. Most people will note these changes when beginning a quality probiotic or when increasing fiber in their diet.

Increased Energy Levels and Mental Clarity

Noticeable boosts in energy can suggest that the probiotics are helping to enhance nutrient absorption⁹ (such as B vitamins and iron) and positively impacting your health in other ways, such as by lowering inflammation, which is one cause of fatigue.

Feelings of mental clarity, focus, and improved mood can also indicate that the gut-brain axis is being positively influenced¹⁰ by the probiotics.

Balanced Vaginal Health

For women, optimal gut health is tied to a reduction in vaginal discomfort and infections. Fewer instances of UTIs, yeast infections, and even vaginal dryness can suggest that the probiotics are helping maintain a healthy vaginal flora¹¹.

Healthy vaginal flora, specifically the lactobacillus species, help maintain an optimal PH. This is important for inhibiting the growth of bacteria that lead to bacterial vaginosis (BV) and yeast overgrowth.

Less itching, burning, discharge, and discomfort may be a sign vaginal flora are shifting for the better.

More Stable Weight

The microbes living in your gut can affect your appetite, cravings, insulin sensitivity, and weight. You may find that you have an easier time managing hunger and losing weight with greater appetite control and fewer cravings, as probiotics can help support a healthy body composition and metabolism¹².

Improved PMS Symptoms and Period Cramps

In one randomized, double blind, placebo controlled study¹³ using a combination of Lactobacillus and Bifidobacterium species it was found that after 3 months participants experienced improved mental health and lower non-steroidal anti-inflammatory (NSAID) use.

Other strains of Lactobacillus species have been shown¹⁴ to improve irritability that can occur in the premenstrual phase after supplementing for 3 menstrual cycles.

Improved Skin Health

If you've previously been prone to acne breakouts or skin irritation, probiotics can help your skin to become clearer, less inflamed, and overall healthier-looking with fewer breakouts and less sensitivity.

Better Sleep Quality

Probiotics can indirectly influence sleep through their effects on stress and inflammation levels. Due to the gut-brain connection and the production of hormones inside the gut, a healthier gut can potentially lead to improved sleep patterns and fewer symptoms of insomnia.

Improved Immune Function

A large percentage of your immune system (about 70% to 80%) is located within your gut¹⁵, so you might experience fewer occurrences of ailments¹⁶ like colds, flu, or other infections, indicating that the probiotics are helping to strengthen your immune system.

Reduced inflammation

You might notice improvements in inflammatory conditions¹⁷ like joint pain or skin issues, as probiotics help modulate the body's inflammatory response.

Tips for Selecting High-Quality Probiotics

When choosing probiotic supplements, consider these factors to ensure you choose a safe and effective product:

Science-backed strains: Look for probiotic supplements with strains that have been clinically studied for their health benefits¹⁸, such as strains like¹⁹ Lactobacillus acidophilus, Bifidobacterium lactis, Lactobacillus rhamnosus, and Saccharomyces boulardii that have been shown to support gut health.

Potency/CFU count: Check the colony-forming units (CFUs) count to ensure it matches your specific health needs. Consider special formulation features, such as delayed-release capsules or refrigeration requirements, based on your needs and preferences since these can affect potency and how long the supplement stays fresh before expiring.

Diversity of strains: Select probiotics with diverse strains to promote a balanced microbiome. For example, try a probiotic with at least two to four different strains. Taking spore-based probiotics can also offer significant benefits to improving gut health.

Third-party testing: Choose products that guarantee potency through the expiration date and have undergone third-party testing for quality and purity.

Inclusion of prebiotics: The benefits of probiotic supplements are amplified when they also contain prebiotics, which are specific fibers that help “feed” probiotics and allow them to thrive in your microbiome. This duo also promotes the overall diversity and health of the microbiome.

Positive reviews: Read customer reviews and seek recommendations from healthcare professionals to find reputable brands with positive user experiences.

What's the Best Probiotic for Women?

Finding a probiotic specifically developed for women can be highly beneficial for women’s health and hormones. Research shows the Lactobacillus strains mentioned previously can be especially helpful for women, along with prebiotics. The best probiotic for women will be formulated with the particular strains that support both the gut and vaginal microbiome.

These specific strains have undergone clinical trials and have been shown to benefit women’s digestive, gut, and hormonal health. That’s why they are included, along with beneficial Bacillus species, prebiotics, and antioxidant-rich aronia berry, in my Women’s Probiotic formula, which can support overall gut function, immune defenses, a balanced vaginal microbiome, healthier menstrual cycles, glowing skin, and defenses against yeast that can cause itching and discomfort.

Remember, when in doubt, you can always consult with a healthcare provider to determine the most suitable probiotic strain(s) and dosage for your symptoms or goals.

Are Probiotics Effective Immediately?

In general, probiotics are not considered quick-fix solutions. Significant improvements in your health can take several days²⁰, weeks, or even several months to become noticeable after you start taking probiotics. On average, it takes about three months to experience noticeable change.

Every person's microbiome is unique²¹, so no two people will react exactly the same way to a probiotic supplement. While some people can experience noticeable improvements in digestion and other markers of health shortly after starting probiotic supplementation, for others, it can take longer.

Overall, the timeframe for probiotics to take effect varies²². Factors such as the specific probiotic strains, dosage, duration of use, and individual health status all influence the onset of probiotic benefits. In addition, the amount of prebiotics in your diet can also play a role in. Read more about the best prebiotics here.

Patience and consistent use are key when integrating probiotics into your routine.

And, to reap the most benefits from probiotic supplements, it's important to combine them with a healthy, anti-inflammatory diet and ideally probiotics from fermented foods, too, such as yogurt, kefir, kimchi, and sauerkraut which contain a different mix of probiotic strains that improve microbial diversity²³ in your gut microbiome.

Signs That Your Probiotic May Not Be Working

Despite their potential benefits, probiotics don't always yield the desired outcomes for everyone.

Signs that probiotics may not be working as expected can potentially include:

Persistent digestive discomfort, such as increased bloating and gas that don't resolve within a few weeks.
Worsened symptoms, such as increased skin breakouts, diarrhea, or constipation that persists beyond a few weeks.
No sign of improvement in health concerns, such as constipation or recurring vaginal infections, for example.

Why don't probiotics work for everyone, and why can people have varying reactions to the same type of probiotic supplement?

Several factors can contribute to a lack of response or effectiveness when taking probiotics:

Gut diversity: The diversity of gut microbiota varies widely among people, influenced by factors such as genetics, diet, lifestyle, and environmental exposures. If someone's gut microbiome is already well-balanced and diverse, introducing additional probiotics may not produce noticeable changes.

Specific strains being taken: The specific strain or combination of strains in the probiotic supplement may not be compatible with someone's unique gut microbiota. Each strain of probiotic bacteria has different functions and can interact differently with the existing microbiome, leading to varying effects.

Certain lifestyle factors: Factors such as diet high in processed foods, chronic stress, lack of sleep, and frequent antibiotic use can disrupt the gut microbiota, making it more challenging for probiotics to establish and thrive. Other medications like chronic use of NSAIDS and in some cases, oral contraceptive pills may also contribute to dysbiosis.

Individual health conditions: Health issues such as underlying gastrointestinal disorders or immune system dysfunction can impact the effectiveness of probiotics. In such cases, addressing the underlying health issue may be necessary before probiotics can lead to benefits.

Inconsistent dosing and poor-quality supplements: Taking a low dose, a poor-quality product, or improper storage conditions can also affect probiotic efficacy. Ensuring proper selection, dosage, and quality of probiotic products helps maximize their effectiveness.

What To Do If Your Probiotic Isn't Working

Among those who don't experience any positive changes after an extended period of taking probiotics (such as two or three months), it's wise to reassess the type of probiotic being taken and the dosage.

Trying several different formulas, especially ones that contain multiple strains, can be helpful—since different probiotic strains work in different ways.

Additionally, if you have a known health condition, such as IBS or a condition that affects your immune system, it's best to work with a healthcare provider to determine the best type of probiotic for your needs and goals.

Common Side Effects of Probiotics

While probiotics are considered generally safe for most people²⁴, certain side effects can occur, particularly during the initial stages of supplementation when the gut is adjusting to the new microbes.

Common side effects of probiotics²⁵ supplements can include:

Changes in regularity and transient time, such as constipation or diarrhea.
Gastrointestinal symptoms such as bloating, gas, changes in stool consistency, and mild abdominal discomfort.

Usually, probiotic side effects are mild and temporary as the gut microbiota undergoes adaptation to the introduction of probiotic strains.

Side effects from probiotics typically last only one to three weeks and then diminish; however, if symptoms occur for longer than several weeks, talk to your provider to get their opinion, try another formula, adjust the dosage, or stop taking the probiotic.

Abnormal Side Effects to Monitor:

While mild gastrointestinal symptoms are considered normal during probiotic use, you should still be vigilant for any unusual or severe side effects that can possibly indicate an adverse reaction or allergic response²⁶ to some probiotics. These types of side effects are more common in people with compromised immune systems or conditions such as inflammatory bowel disease²⁷.

If you experience the abnormal side effects below, stop taking probiotics and reach out to your doctor for help:

Persistent or severe abdominal pain.
Persistent or severe diarrhea or constipation.
Signs of allergic reactions such as rash, itchiness, or trouble breathing.

Key Takeaways on How Long It Takes Probiotics to Work

The potential benefits of probiotics extend beyond digestion, with research suggesting they can help modulate inflammation, balance hormones, alleviate allergy symptoms, enhance mood, and even support weight management.
The effectiveness of probiotics and the timeline for their benefits are influenced by factors, including specific probiotic strains, dosage, duration of use, and health status.
Probiotics can take several weeks to several months to start contributing to noticeable health benefits.
Look for probiotic products containing well-researched strains, those that guarantee potency through expiration, utilize targeted delivery systems to protect probiotic viability, and are free from unnecessary additives, fillers, or allergens.

References

About The Author

Dr. Jolene Brighten

Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.