What Do Doctors Do with the Remaining Botox when They Only Use 10-15 Units from a 50 Unit "Single-unit" Vial of Botox?

Curious how it works when you get only say 10-20 units of botox, what happens to the rest of the product they did not use on you? Can it be reused with a new syringe/needle on another patient? How does this work and is it sterile to reuse the vials??

Doctor Answers 16

Dosage of Botox, how is the product stored

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Botox comes in 50 unit and 200 unit vials.  If only 10 or 20 units are used from a 50 unit vial, the remainder is stored (refrigerated) for a few days. The product is removed with a new sterile needle each time so there is no risk of contamination.

Best wishes,


Beverly Hills Plastic Surgeon
4.9 out of 5 stars 410 reviews

Left over botox

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As the Botox liquid in the bottle is not contaminated from a sterile syringe that is used to draw up the liquid, the left over Botox is then used for the next syringe which is a fresh, sterile syringe and needle. The bottle is dated and refrigerated. In busy practices the bottle only lasts a day to a few days and its effectiveness is not compromised. Don't confuse this with a situation if there would happen to be left over Botox in the syringe aftere your treatment. That doesn't happen in my practice as we draw up only what we need for that particular patient.  But if in another doctor's practice, not all the botox in the syringe were used to treat their patient, the left over would be discarded because that would be considered to risk a cross contamination if used, even with a new sterile needle.

Ronald Shelton, MD
Manhattan Dermatologic Surgeon
4.9 out of 5 stars 39 reviews

Units of botox

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The average area treated typically requires 10-30 units of botox cosmetic. Botox from the same vial can be used to treat multiple areas in the same patient or multiple patients. As long as proper sterile technique is used to prepare the botox solution and to inject the botox, it is perfectly safe to administer botox to multiple patients from the same vial. In a busy botox practice. Such as mine, once the vial is prepared, it usually is empty within 24 hours of preparation and never sits around long enough to lose its efficacy. If you are receiving botox treatments in a practice that occasionaly performs botox injections, only then would u want to be concerned about what happens to the left over botox in terms of how many weeks has the prepared botox been sitting around.

Anita Mandal, MD
Palm Beach Facial Plastic Surgeon

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When Botox is used it is drawn up sterily from the vial and the specific amount needed is drawn up for that patient.   But, it is also used for other individuals used under the same conditions.

Steven Wallach, MD
New York Plastic Surgeon
4.2 out of 5 stars 30 reviews

There is not such thing as left over.

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The vial comes sterile, is reconstituted in a sterile fashion, and drawn up using sterile technique.  There is no issue using these vials to prepare injections for multiple treatments.  However, BOTOX is best used within 4 hours of reconstitution.  Beyond this time frame, practitioners will often dispose of the remainder of the vial.  The Allergan company has done tests that show the product has virtually no loss of strength for 2 weeks.  By using sterile techniques, the reconstituted agent could be safely used during this time frame.  As a practical reality offices such as mine that uses so much of this agent, what is reconstituted is used almost immediately.  The value of the smaller vial is that less of this agent needs to be reconstituted and this increases scheduling flexibility and reduces the risk of having to waste perfectly fine, but unused product.  This is important because the cost of this agent is very high to both you and the doctor.

Kenneth D. Steinsapir, MD
Beverly Hills Oculoplastic Surgeon
4.9 out of 5 stars 26 reviews

BOTOX® is very stable

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Over the past 20 years that BOTOX® has been on the market for cosmetic and therapeutic indications, systems and procedures have been developed for the safe and effective administration of this medication.

The desired dose is drawn up under sterile conditions from the vial and administered to the patient using a very fine needle, generally 30 or 31 gauge. The remaining BOTOX® is stored under sterile conditions until it is needed for another patient. Experience has shown that, when properly handled, BOTOX® remains stable for at least several weeks after it is reconstituted. There is less experience with stability after reconstitution of other formulations of BTX-A, for example Dysport® and XEOMIN®, so I will not comment on them.

Because BOTOX® is very stable after reconstitution, there is little or no waste, and this helps to keep the cost of treatment reasonable.

Kevin C. Smith, MD
Niagara Falls Dermatologic Surgeon

What Does my MD do With Old Botox Vials?

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Hi Plump.  As many of the other practitioners have explained, the use of a Botox for multiple patients is performed in a way as to keep the product sterile.  The most basic explanation is that the needles used to inject the Botox are not reinserted into the Botox vial once they have been used on a patient.  This ensures that the sealed vial remains sterile.

Botox does expire once it is mixed with saline and we usually use it within 1-2 days of mixing.  The manufacturer recommends that the product be thrown out 2 weeks after it is mixed with saline.  Check the link below regarding the Botox safety.


Harold J. Kaplan, MD
Los Angeles Facial Plastic Surgeon
4.4 out of 5 stars 7 reviews

Remaining Botox remains sterile in vial

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A syringe is used to draw up the desired amount of Botox for each patient from the vial of Botox.  The rest remains sterile in that vial until more is drawn up with another syringe for the next patient and so on until the vial is empty.  This is called a multi-dose vial.

Francis R. Palmer, III, MD
Beverly Hills Facial Plastic Surgeon
4.7 out of 5 stars 28 reviews

Multi-dose vials mean multiple patients per vial.

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Botox comes in a 50 or 100U vial in the us.  It is mixed up with saline and drawn into syringes as it is used.  We never "re-load" a syringe that has been in the patient.  But one vial can treat more than one patent.  We buy the 100 U vials and get 2-3 patients out of it.

Ritu Chopra, MD
Beverly Hills Plastic Surgeon
5.0 out of 5 stars 34 reviews


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I typically draw up how ever much of Botox that I need and then the rest I refrigerate. Typically in most practices, Botox sits in the the refrigerator for just a few days because it gets used up pretty quick. For example, we open a new bottle almost every morning and sometimes many times during the day. Dr. Ben Behnam.

Ben Behnam, MD
Santa Monica Dermatologic Surgeon

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.