Do Probiotics Need to Be Refrigerated? The Truth About Storage

Overview

• Not all probiotics need to be refrigerated; it depends on their formulation and storage technology.
• Advanced probiotics can remain viable at room temperature thanks to technologies like lyophilization.
• Temperature fluctuations and moisture can be some of the biggest stressors to probiotic efficacy.
• If a probiotic requires refrigeration, it doesn’t mean it’s a better quality.
• Focus on scientific evidence, formulation, and delivery technology when choosing a probiotic.

You’ve probably seen them in the refrigerated section at the pharmacy or health food store—those small bottles of probiotics claiming to support digestive balance. But wait—the ones you ordered online arrived in a regular box, at room temperature. What gives? What’s the difference? Is one better than the other?

If you’re wondering whether probiotics actually need to be refrigerated, you’re not alone. The answer might surprise you: Not all probiotics require refrigeration, and refrigeration doesn’t necessarily indicate superior quality or effectiveness.

Let’s clear up probiotic storage requirements and focus on what really matters when it comes to keeping these beneficial microbes alive and well so they can do their job in your gut.

The Science Behind Probiotic Storage

To understand probiotic storage requirements, we first need to appreciate what we’re preserving: billions of living, health-promoting bacteria.

Probiotics, by definition, are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.”¹ The key word here? Live.

For probiotics to do their job, they need to survive three important stages of their journey:²

1. Manufacturing to storage
2. Storage to consumption
3. Consumption to their target site (like the colon)

Each stage presents unique challenges, and several factors—such as temperature, moisture, protective delivery systems and packaging technologies—can impact their survival along the way.

Temperature: Friend or Foe?

Temperature can have varying effects on probiotic survivability based on specific strain characteristics.³  For example, heat stress can increase metabolic activity in addition to cell membrane fluidity, potentially leading to cell damage and death.^4,5  On the other hand, freezing temperatures can form ice crystals that damage bacterial cell walls.⁶ 

Thankfully certain probiotics are formulated to withstand these extremes using preservation techniques like the addition of cryoprotectants—compounds like skim milk or trehalose that protect bacterial cells after freeze-drying them.⁷  This allows some shelf-stable probiotics to remain viable despite temperature shifts.

So, generally, extreme temperatures can be more foe than friend, since they  can stress probiotics. But with the right formulation and effective preservation methods, some probiotics are better equipped to survive the ride.

Moisture: The Silent Killer

While temperature seems to get most of the attention, moisture can often be a large  threat to probiotic survivability.⁸ When probiotic organisms are exposed to moisture, they can prematurely activate, ultimately impacting their survival.⁷

That’s why you’ll often find little silica packets in probiotic containers—they’re there to absorb moisture and keep your beneficial bacteria in a dormant, energy-conserving state until they’re ready to get to work in your gut. Seed’s DS-01® goes a step further with a unique nested capsule design that creates a moisture-controlled environment, helping protect the probiotics until they reach your intestines.

Enter Lyophilization: The Freeze Drying Game-Changer

Many probiotic supplements typically undergo a process called lyophilization—essentially a method of freeze-drying that removes water while preserving the microorganism’s structure and increasing viability.^6,7

During this process,bacterial strains are put into a dormant state through the removal of moisture content until they come back into contact with water, at which point they rehydrate to become active.⁸ This innovation has revolutionized probiotic stability, allowing many formulations to remain viable at room temperature for extended periods of time. 

When Refrigeration Matters (And When It Doesn’t)

Not all probiotics are created equal when it comes to storage requirements. Here’s when refrigeration matters, and when it’s probably unnecessary.

Probiotics That Benefit From Cold Storage

Generally speaking, these types of probiotics may require refrigeration:

• Liquid Probiotics: Without the proper protection, such as the addition of cryoprotectants or usage of protective encapsulation, certain microorganisms in liquid formulations may be more vulnerable to environmental factors.^5,7
• Products Without Advanced Stabilization Technologies: Formulations that have not undergone stabilization processes, such as lyophilization, may experience a significant decrease in survivability due to premature activity caused by excess moisture retention.⁸ 
• Products With Specific Strain Requirements: Some bacterial strains are simply more heat-sensitive than others.³

When Refrigeration Is Unnecessary

Many advanced probiotic supplements don’t require refrigeration thanks to innovations in microencapsulation, lyophilization, protective delivery systems, and packaging technologies.

Shelf-stable probiotics typically feature:

• Lyophilized (Freeze-Dried) Bacteria: These dormant microbes can spring back to life when they encounter moisture, such as in your digestive tract.^6,7 
• Protective Delivery Systems: Advanced technologies like enteric coatings, microencapsulation, or capsule-in-capsule designs shield probiotics from environmental stressors.^5,9,10
• Desiccants or Moisture-Controlling Packaging: Proper packaging that prevents moisture is crucial, especially when using dry ingredients in formulations. Moisture can be particularly harmful for synbiotics, as certain prebiotics tend to absorb moisture, which can negatively impact the probiotics. Storage bottles with moisture-absorbing desiccants, such as silica gel packets, are commonly used to maintain low humidity levels and prevent water absorption.^11,12 

The Refrigeration = Quality Myth

There’s a common belief that refrigerated probiotics must be superior to shelf-stable alternatives. But that’s not always the case. While some probiotic strains may inherently require refrigeration for optimal stability, for many others, the need for refrigeration often reflects limitations in formulation technology rather than superior potency.^2,3 

Dirk Gevers, Ph.D., a microbiome expert, explains, “If a probiotic doesn’t survive at room temperature, it could mean the product is poorly made, has too few live bacteria, or doesn’t have enough extra bacteria to account for loss during storage.” 

In other words, products that need to be refrigerated may actually be less stable—as this can signal they haven’t been designed with the protective technologies that allow for room temperature storage. A well-designed, shelf-stable probiotic may actually deliver more live bacteria to your gut than a refrigerated one with inferior stabilization or improper storage technique.^12,13 

How to Properly Store Your Probiotics

Regardless of whether your probiotics require refrigeration, proper storage is essential for maintaining probiotic viability and efficacy.^12,14  

Here are some general guidelines:

Follow Product-Specific Instructions

The most important rule of probiotic storage is to follow the manufacturer’s instructions. 

If the label says “refrigerate,” do so. 

If it says “store in a cool, dry place,” a pantry, medicine cabinet or another location away from heat and humidity sources will suffice.

Temperature Considerations Beyond Refrigeration

Even shelf-stable probiotics can have temperature limits; therefore, it’s important to ask companies about their stability data. To play it safe, avoid leaving them in hot cars, near radiators, or in direct sunlight for extended periods of time, which can exceed the upper temperature threshold.

Going out of town? Consider using an insulated bag for short trips if you’ll be in hot environments. For longer journeys, small cooling packs (not freezing!) can help maintain appropriate temperatures.

Needless to say, formulation and delivery technology are extremely important for ensuring probiotic efficacy.

Take Seed’s DS-01® Daily Synbiotic, for example. It uses ViaCap® technology—a capsule-in-capsule system that protects probiotic strains from oxygen, moisture, heat and stomach acid. As probiotics are most effective when they make it to your colon alive, this nested capsule technology is a vital aspect of DS-01® .  Think of it like sending probiotic strains on a flight with priority boarding and top-tier travel insurance—they’ll arrive at their destination intact and ready to work, no refrigeration required.

Moisture and Oxygen Protection

Moisture and oxygen exposure can significantly impact probiotic viability.^4,7,8

To protect your investment in a quality probiotic…

• Keep containers tightly sealed when not in use
• Store in recommended packaging that is designed to protect contents ¹¹
• Leave desiccant packets (those little silica gel packs) in the container
• Avoid storing in humid areas like bathrooms ⁴
• Use dry hands or a clean, dry utensil to remove product

Many high-quality probiotics come in moisture-resistant, opaque containers or blister packs specifically designed to protect against environmental factors.^2,11

Signs Your Probiotics May No Longer Be Viable

Even with proper storage, probiotics have a limited shelf life. Here are some indicators that your probiotics may have lost potency:

• Changes in Appearance: Discoloration, clumping, or unusual texture changes
• Changes in Smell: Development of off-odors or significant changes in scent
• Moisture in the Container: Indicates potential water exposure that could prematurely activate and then kill the probiotics ⁸
• Past Expiration Date: All living things expire, and this includes the beneficial bacteria in probiotics.⁸  While some products may retain potency beyond the expiration date, it’s generally best to replace expired probiotics to ensure efficacy ¹²

Note that unlike food spoilage, non-viable probiotics aren’t typically harmful—they simply won’t provide the intended benefits.¹² When in doubt, it’s best to replace them with a fresh supply.

The Key Insight

The refrigeration needs of probiotics aren’t one-size-fits-all. While some formulations benefit from cold storage, many well-formulated probiotics are designed to remain viable at room temperature thanks to advances in stabilization and delivery technologies.

When choosing a probiotic, focus less on whether it’s refrigerated and more on evidence-based factors like:

• Research backing the specific strains ¹⁵
• Transparent potency information (AFU/CFU counts)
• Demonstrated delivery technology to protect probiotics through digestion ^2,5,10 
• Clear storage instructions based on stability testing
• Manufacturing quality and testing standards

Properly stored, high-quality probiotics—whether refrigerated or shelf-stable—can deliver billions of beneficial bacteria to support your microbiome. The most important thing? Finding a product that fits seamlessly into your lifestyle, supporting consistent, daily use for optimal results.

Find out if probiotics are right for you with a short quiz!

Frequently Asked Questions (FAQs)

Do Refrigerated Probiotics Work Better Than Shelf-Stable Ones?

Not necessarily. Refrigeration requirements reflect stability differences and limitations rather than superior quality. A well-formulated, shelf-stable probiotic with proven delivery technology may still successfully deliver efficacious, live bacteria to your gut without the need of having to be refrigerated.^8,13,15

What Happens If I Accidentally Leave My Probiotics in a Hot Car?

Brief exposure to heat is unlikely to completely destroy all beneficial bacteria, but it may reduce potency, depending on the specific stability technology utilized.^3,16  If your probiotics were exposed to high temperatures for more than a few hours, it’s a good idea to review the product’s stability testing information. Consider replacing them if possible, especially if they show any physical changes.

Should I Refrigerate My Probiotics While Traveling?

For shelf-stable probiotics, room temperature storage is generally fine for travel. If you’re visiting a very hot climate, storing them in the coolest available location (away from direct sunlight) is advisable. For probiotics that require refrigeration, travel coolers or insulated bags with ice packs can help maintain proper temperature.

Why Do Some Probiotics Need Refrigeration While Others Don’t?

The need for refrigeration depends on several factors, including bacterial strains, formulation methods, delivery systems, and packaging.^10,15  Advances in stabilization technologies, like lyophilization, have made it possible to create shelf-stable probiotics that remain viable at room temperature.^2,7

Is It Okay to Refrigerate Probiotics That Don’t Require It?

In most cases, yes—but with a few considerations. Refrigeration won’t harm shelf-stable probiotics, but it’s hard to say if it offers any significant added benefit in terms of stability. If you live in a particularly warm climate, storing them in the fridge could provide some extra peace of mind, but it’s not strictly necessary. Just be sure to keep an eye out for any condensation or moisture, as this could affect the quality of your probiotics.

How Can I Tell If My Probiotics Are Still Alive?

Unfortunately, you can’t visually determine bacterial viability without laboratory testing. The best approach is to purchase from reputable companies that conduct stability testing, store your probiotics properly, and use them before the expiration date.^12,14