How Long Can You Keep Botox Once Opened? The Definitive Storage Guide

October 10, 2025 •

4 min read

According to official manufacturer guidelines, reconstituted Botox should be used within 24 hours of opening to ensure optimal potency and sterility. However, some clinical studies and common off-label practices in aesthetic medicine suggest that, when stored correctly under refrigeration, the product may retain its efficacy for much longer.

Quick Summary

Official guidelines state reconstituted Botox must be used within 24 hours and kept refrigerated. While some clinical studies suggest efficacy can be maintained for weeks under controlled, refrigerated conditions, this is considered an off-label practice and poses potential risks of contamination and reduced potency.

Key Points

Manufacturer vs. Practice: The official recommendation from manufacturers is to use reconstituted Botox within 24 hours and discard the remainder.
Extended Shelf Life: Clinical studies suggest that reconstituted Botox can maintain potency for up to 4-6 weeks if properly refrigerated (2°C–8°C) using bacteriostatic saline.
Contamination Risk: The primary safety concern with extended storage is the potential for bacterial contamination from multiple withdrawals over time.
Proper Refrigeration is Key: Reconstituted Botox must be stored in a medical-grade refrigerator with stable temperature controls, not a standard household fridge.
Freezing is Detrimental: Never freeze reconstituted botulinum toxin, as this will degrade the protein and render it ineffective.
Professional Discretion is Paramount: The choice between adhering to the 24-hour rule or practicing extended storage rests with the medical professional, who must prioritize patient safety and adhere to sterile procedures.

The Critical First Step: Reconstitution

Before any discussion of how long you can keep Botox once opened, it's essential to understand the reconstitution process. Botox is supplied as a lyophilized (freeze-dried) powder in a sterile vial. A clinician reconstitutes it by adding a diluent, typically sterile saline, turning the powder into an injectable solution. It is at this moment that the "timer" on the opened vial effectively starts.

The Official Manufacturer's Stance: The 24-Hour Rule

Manufacturers, including Allergan (the maker of BOTOX® Cosmetic), provide strict instructions for handling their products to ensure maximum safety and efficacy. Their recommendation is unequivocal: reconstituted botulinum toxin should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F) and used within 24 hours. The reasoning behind this is two-fold:

Potency Degradation: As a fragile protein, the botulinum toxin can begin to lose its effectiveness over time once reconstituted, especially if exposed to light, heat, or improper handling. Adhering to the 24-hour rule ensures patients receive the intended and expected results.
Sterility and Contamination Risk: The reconstitution process opens the sterile, sealed vial. While sterile saline is used, subsequent withdrawals from the vial increase the risk of introducing bacteria, which can compromise the product and lead to infection. The 24-hour limit acts as a strict safety protocol to minimize this risk.

Extended, Off-Label Storage: What the Clinical Research Suggests

In the real-world clinical setting, particularly in busy aesthetic practices, the 24-hour rule can lead to significant product waste. The cost of a vial of botulinum toxin is high, and a single patient may only require a fraction of the vial's contents. Consequently, multiple studies and a 2014 consensus statement by the American Society for Dermatologic Surgery (ASDS) have explored the possibility of extending storage times.

These studies have consistently found that when reconstituted with bacteriostatic saline (which contains a preservative) and stored under continuous refrigeration, the botulinum toxin can maintain a high degree of potency for several weeks, with some research indicating efficacy for up to four to six weeks. This prolonged storage is widely practiced by experienced injectors to reduce waste and cost.

Best Practices for Extended Storage (Off-Label):

Use Bacteriostatic Saline: Using bacteriostatic (preserved) saline for reconstitution adds a layer of antimicrobial protection, helping to prevent contamination during multiple withdrawals.
Dedicated Medical Refrigeration: Use a medical-grade refrigerator that maintains a consistent temperature between 2°C and 8°C. Frequent temperature fluctuations in standard household refrigerators can degrade the product.
Strict Aseptic Technique: Every withdrawal from the vial must be performed with strict sterile procedures to minimize the risk of bacterial introduction.
Proper Labeling: The vial should be clearly labeled with the date and time of reconstitution to ensure accurate tracking.
Protection from Light: Storing the vial in its original carton or another light-protective container is crucial, as light exposure can contribute to potency loss.

The Risks of Improper Storage

Failing to follow proper storage protocols, whether manufacturer-recommended or off-label, can lead to serious consequences. These include:

Reduced Clinical Effectiveness: A loss of potency means the injections may not produce the desired muscle-relaxing effect, leading to suboptimal or failed treatment outcomes.
Increased Contamination Risk: As mentioned, multiple needle punctures of the vial's stopper can introduce bacteria. This risk escalates with each subsequent use and with longer storage duration. The consequences of injecting a contaminated product could include infection at the injection site.
Compromised Patient Safety: The primary concern for any medical procedure is patient safety. Any deviation from standard sterile procedures or protocols increases the potential for adverse effects.

Manufacturer vs. Extended Storage Comparison


Feature	Manufacturer's Recommendation	Extended (Off-Label) Practice
Usage Timeline	Use within 24 hours of reconstitution.	Use typically within 4-6 weeks of reconstitution.
Diluent	Sterile, preservative-free saline is standard.	Bacteriostatic (preserved) saline is often used to extend shelf life.
Storage Temperature	Refrigerate at 2°C to 8°C in a medical fridge.	Refrigerate at 2°C to 8°C in a medical fridge.
Primary Goal	Maximize potency and minimize contamination risk for optimal patient safety.	Optimize product usage and cost-effectiveness while maintaining efficacy and sterility under controlled conditions.
Sterility	Assumed high sterility due to short storage time.	Increased risk of contamination with each withdrawal over time.
Potency	Guaranteed optimal potency due to fresh use.	Studies show good potency, but theoretical risk of gradual decline over time.

Conclusion: The Importance of Professional Judgment

There is a clear distinction between the ultra-conservative manufacturer's instructions and the well-documented, but still off-label, extended storage methods used in many clinical settings. The manufacturer's 24-hour rule is the safest and most cautious approach, guaranteeing efficacy and minimizing risk. Extended storage, supported by clinical studies showing retained potency, is a common practice that can reduce costs and waste. However, this approach requires impeccable sterile technique, diligent temperature monitoring with medical-grade refrigeration, and an understanding of the inherent, albeit small, increase in contamination risk. Ultimately, the decision to practice extended storage must be made by a qualified and experienced medical professional who weighs the potential benefits against the risks and prioritizes patient safety above all else. For a more detailed look into clinical guidelines and consensus statements, consider consulting authoritative sources like those published by the American Society for Dermatologic Surgery.

Frequently Asked Questions

The official manufacturer's recommendation is to use the reconstituted botulinum toxin within 24 hours. The opened vial should be stored in a medical-grade refrigerator at a temperature between 2°C and 8°C during this period.

No, it is not recommended. Standard kitchen refrigerators are prone to temperature fluctuations that can affect the potency of the product. A medical-grade refrigerator is necessary to maintain a consistent, controlled temperature range.

If used after the manufacturer's recommended time frame, the botulinum toxin may have lost some of its potency, potentially resulting in a less effective treatment outcome. The risk of bacterial contamination also increases over time.

No, freezing is not recommended. Freezing botulinum toxin can cause the protein to degrade and lose its effectiveness. It should always be stored in a refrigerated state, never frozen.

Some clinical practices store reconstituted botulinum toxin for several weeks to reduce product waste and cost. This is an off-label practice supported by studies showing that under strict, controlled refrigerated conditions, the product can retain its potency.

Bacteriostatic saline contains a preservative, which helps inhibit bacterial growth. Using bacteriostatic saline is one factor in the clinical practice of extended storage, as it adds an extra layer of protection against contamination over time compared to standard sterile saline.

While studies suggest retained potency, off-label storage carries a higher inherent risk of contamination and degradation compared to using a freshly reconstituted vial. The decision to use such a vial is up to the medical professional's judgment and risk assessment.