Free clinical reference tool
Botox Reconstitution Calculator and Dilution Chart
Botox reconstitution is simple division: units per 0.1 mL = vial units ÷ diluent mL ÷ 10. Per the Botox Cosmetic prescribing information, a 100 Unit vial reconstituted with 2.5 mL of preservative-free 0.9% saline gives 4 Units per 0.1 mL, and a 50 Unit vial with 1.25 mL gives the same. Use the calculator and dilution chart below for any vial and volume.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
Reconstitution calculator
Pick the product and vial, then the saline volume you add. Results update as you type.
This volume appears in the label's dilution table for this vial.
* Volume listed in the label's dilution table for this vial.
Botox Cosmetic 100 U in 2.5 mL
4 U per 0.1 mL
- Units per mL
- 40
- Units per 0.01 mL mark
- 0.4
A math aid. Confirm against the product label and your protocol; dosing and treatment decisions belong to the treating provider.
Volume to draw for a number of Units
20 U = 0.5 mL (50 marks of 0.01 mL).
Reverse: diluent for a target concentration
Add 2.5 mL to the 100 U Botox Cosmetic vial to reach 4 U per 0.1 mL.
Units per syringe mark
Mark spacing differs by manufacturer. Check your own syringe before you rely on a row.
| Syringe | Mark | Units per mark | Units in a full syringe |
|---|---|---|---|
| 0.3 mL insulin syringe | 1 mark = 1 insulin unit = 0.01 mL (some have half-unit marks) | 0.4 | 12 |
| 0.5 mL insulin syringe | 1 mark = 1 insulin unit = 0.01 mL | 0.4 | 20 |
| 1 mL insulin syringe | 1 insulin unit = 0.01 mL; many have a line every 2 units (0.02 mL) | 0.4 | 40 |
| 1 mL tuberculin syringe | 0.01 mL per mark | 0.4 | 40 |
Dilution chart: Botox Cosmetic 100 U
Units for a 100 U vial at each diluent volume. Rows marked with * use a volume from the label's dilution table.
| Diluent (mL) | Units per mL | Units per 0.1 mL | Units per 0.01 mL mark |
|---|---|---|---|
| 0.5 | 200 | 20 | 2 |
| 1 | 100 | 10 | 1 |
| 1.25 | 80 | 8 | 0.8 |
| 1.5 | 66.667 | 6.667 | 0.6667 |
| 2 | 50 | 5 | 0.5 |
| 2.5 * | 40 | 4 | 0.4 |
| 3 | 33.333 | 3.333 | 0.3333 |
| 4 | 25 | 2.5 | 0.25 |
| 5 | 20 | 2 | 0.2 |
Units per 0.1 mL = vial Units ÷ diluent mL ÷ 10. Diluent: Sterile, preservative-free 0.9% Sodium Chloride Injection, USP. A math aid; confirm against the Botox Cosmetic prescribing information (DailyMed label version 10/18/2024). Units are not interchangeable between botulinum toxin products. Printed from prospyrmed.com/tools/botox-reconstitution-calculator.
How to reconstitute Botox and other neurotoxins
Every product below ships as a freeze-dried powder in a single-dose vial. The steps in the prescribing information are the same in outline. Your product's label controls the details.
- Draw up the preservative-free 0.9% sodium chloride volume you chose, using the label table for your vial.
- Inject the saline slowly into the vial. The vacuum should pull it in. The Botox Cosmetic, Dysport, Daxxify, Jeuveau and Letybo labels all say not to use a vial that has no vacuum.
- Mix gently. Botox Cosmetic, Jeuveau and Letybo say to rotate the vial. Xeomin says to swirl and invert, and not to shake vigorously.
- Record the date and time of reconstitution and use the product within the label window: 24 hours for Botox Cosmetic, Dysport, Xeomin, Jeuveau and Letybo, 72 hours for Daxxify, refrigerated at 2°C to 8°C.
Vials are single-dose. The labels say to use a reconstituted vial for one injection session and one patient and to discard the rest.
Tracking which vial was opened, when, and how many Units each patient received is a charting job. Prospyr's inventory management tracks Units by vial and lot, and charting keeps the Units you record on each patient's visit.
Botox units per 0.1 mL and per mL: formula and worked examples
Concentration depends only on the Units in the vial and the volume of saline you add:
- Units per mL = vial Units ÷ diluent mL
- Units per 0.1 mL = Units per mL ÷ 10
- Units per 0.01 mL syringe mark = Units per mL ÷ 100
- mL to draw for N Units = N ÷ Units per mL
- Diluent for a target = vial Units ÷ (target Units per 0.1 mL × 10)
Example 1, label volume. A 100 Unit Botox Cosmetic vial with 2.5 mL of saline is 100 ÷ 2.5 = 40 Units per mL, which is 4 Units per 0.1 mL and 0.4 Units per 0.01 mL mark. This matches Table 2 of the label.
Example 2, a different volume. The same 100 Unit vial with 1 mL of saline is 100 Units per mL, or 10 Units per 0.1 mL. Drawing 20 Units takes 20 ÷ 100 = 0.2 mL. The label's Botox Cosmetic table does not list 1 mL, so this is arithmetic only, not label guidance.
Example 3, reverse. To get 4 Units per 0.1 mL from a 50 Unit vial: 50 ÷ (4 × 10) = 1.25 mL.
The 1 mL tuberculin and insulin syringes used in many practices are marked in hundredths of a milliliter. A U-100 insulin syringe's "units" are insulin units equal to 0.01 mL, not toxin Units. The table in the calculator converts each mark to toxin Units for your dilution.
Dysport, Xeomin, Daxxify, Jeuveau and Letybo reconstitution: label reference
Below are the reconstitution and storage statements, and the doses the labels list for their approved aesthetic indications. Open a product to read it. These are quotations of published label facts, not a recommendation for any patient.
Botox Cosmetic (onabotulinumtoxinA) · 50 / 100 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- 50 Unit vial: 1.25 mL of diluent. 100 Unit vial: 2.5 mL of diluent. Both give 4 Units per 0.1 mL. Inject the diluent slowly; discard the vial if a vacuum does not pull it in; mix gently by rotating the vial.
- Storage and use-within time
- Administer within 24 hours after reconstitution. Store reconstituted product at 2°C to 8°C (36°F to 46°F). Do not freeze. Vials are single-dose only; discard any remaining solution.
- Label-approved doses, approved aesthetic indications
- Glabellar lines: 20 Units in 0.5 mL (4 Units into each of 5 sites)
- Lateral canthal lines: 24 Units in 0.6 mL (4 Units into each of 6 sites)
- Forehead lines with glabellar lines: 40 Units in 1 mL
- Platysma bands: 26 Units in 0.65 mL, 31 Units in 0.78 mL or 36 Units in 0.9 mL, depending on the number of bands
- Label citation
- Botox Cosmetic prescribing information, DailyMed label version 10/18/2024 (printed revision 10/2024). View on DailyMed.
Dysport (abobotulinumtoxinA) · 300 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- The 300 Unit vial is diluted per Table 1 of the label: 0.6 mL gives 50 Units per 0.1 mL, 1.5 mL gives 20, 2.5 mL gives 12 and 3 mL gives 10. For glabellar lines the label lists 12 Units/0.1 mL or 20 Units/0.1 mL. The vial also comes in a 500 Unit size for other indications, which this tool does not cover.
- Storage and use-within time
- Use for one injection session and one patient. Unused reconstituted product may be stored in the original container at 2°C to 8°C (36°F to 46°F), protected from light, for up to 24 hours; discard if not used within 24 hours. Do not freeze.
- Label-approved doses, approved aesthetic indications
- Glabellar lines (adults under 65): 50 Units total, in five equal aliquots of 10 Units (0.08 mL each at 12 Units/0.1 mL, or 0.05 mL each at 20 Units/0.1 mL)
- Label citation
- Dysport prescribing information, DailyMed label version 10/24/2024. View on DailyMed.
Xeomin (incobotulinumtoxinA) · 50 / 100 / 200 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- Table 5 of the label lists diluent volumes for 50, 100 and 200 Unit vials (for example, 1.25 mL on a 50 Unit vial gives 4 Units per 0.1 mL). The vacuum draws the saline in; if it does not, discard the vial. Mix by swirling and inverting; do not shake vigorously.
- Storage and use-within time
- Administer within 24 hours after reconstitution. Store unused reconstituted product in the original container at 2°C to 8°C (36°F to 46°F). Single-dose vial; use for one injection session and one patient.
- Label-approved doses, approved aesthetic indications
- Glabellar lines: 4 Units into each of 5 sites, maximum 20 Units
- Horizontal forehead lines (with glabellar lines): 20 Units forehead plus 20 Units glabellar, maximum 40 Units
- Lateral canthal lines: 4 Units into each of 3 sites per side, maximum 24 Units
- All three areas together: Maximum 64 Units
Retreat no more often than every three months.
- Label citation
- Xeomin prescribing information, DailyMed label version 07/10/2026. View on DailyMed.
Jeuveau (prabotulinumtoxinA-xvfs) · 100 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- 100 Unit vial: 2.5 mL of diluent, giving 4 Units per 0.1 mL and a 20 Unit dose in 0.5 mL. Inject the diluent slowly; discard the vial if a vacuum does not pull it in; mix gently by rotating.
- Storage and use-within time
- Administer within 24 hours after reconstitution. Store unused product at 2°C to 8°C (36°F to 46°F) in the original carton, protected from light. Do not freeze. Single-dose vial; one injection session, one patient.
- Label-approved doses, approved aesthetic indications
- Glabellar lines: 20 Units (0.1 mL / 4 Units into each of 5 sites)
- Label citation
- Jeuveau prescribing information, DailyMed label version 04/28/2023. View on DailyMed.
Daxxify (daxibotulinumtoxinA-lanm) · 50 / 100 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- For glabellar lines: 0.6 mL on a 50 Unit vial or 1.2 mL on a 100 Unit vial, giving 8 Units per 0.1 mL. (The label lists separate volumes for cervical dystonia, which this tool does not cover.)
- Storage and use-within time
- Administer within 72 hours after reconstitution. Store unused reconstituted product at 2°C to 8°C (36°F to 46°F), protected from light. Do not freeze. Use each vial for one injection session and one patient.
- Label-approved doses, approved aesthetic indications
- Glabellar lines: 40 Units (8 Units / 0.1 mL into each of 5 sites)
Administer no more often than every three months.
- Label citation
- Daxxify prescribing information, DailyMed label version 01/07/2026 (printed revision 11/2023). View on DailyMed.
Letybo (letibotulinumtoxinA-wlbg) · 50 / 100 U vials
- Diluent
- Sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
- Reconstitution (aesthetic indication)
- 50 Unit vial: 1.25 mL. 100 Unit vial: 2.5 mL. Both give 4 Units per 0.1 mL. Inject the diluent slowly; discard the vial if a vacuum does not pull it in; mix gently by rotating.
- Storage and use-within time
- Administer within 24 hours after reconstitution. Store unused product at 2°C to 8°C (36°F to 46°F) in the original carton, protected from light. Do not freeze. Discard remaining solution after the injection session.
- Label-approved doses, approved aesthetic indications
- Glabellar lines: 20 Units (0.1 mL / 4 Units into each of 5 sites)
Administer no more often than every three months.
- Label citation
- Letybo prescribing information, DailyMed label version 11/18/2024. View on DailyMed.
Per each prescribing information, potency Units are specific to that product's preparation and assay and cannot be compared to or converted into Units of any other botulinum toxin product. This page does not compare or convert doses between products.
Dilution chart: how to read it
The chart in the calculator lists, for the selected product and vial, the Units per mL, per 0.1 mL and per 0.01 mL mark at each common saline volume. Volumes marked with an asterisk are the ones printed in that label's dilution table for the aesthetic indication. Other rows are arithmetic for practices that choose a different volume under their own protocol.
Dysport, with its larger 300 Unit vial and different Unit scale, shows why you read the chart for the product in your hand. Its label lists 0.6, 1.5, 2.5 and 3 mL for the 300 Unit vial, giving 50, 20, 12 and 10 Units per 0.1 mL. The print button prints just the chart, with the label date, for a treatment-room binder.
Per each prescribing information, potency Units are specific to that product's preparation and assay and cannot be compared to or converted into Units of any other botulinum toxin product.
Frequently asked questions
How do you reconstitute Botox?
Per the Botox Cosmetic prescribing information, add preservative-free 0.9% sodium chloride slowly to the vacuum-dried vial: 1.25 mL for a 50 Unit vial or 2.5 mL for a 100 Unit vial, giving 4 Units per 0.1 mL. Discard the vial if no vacuum pulls the saline in, mix by rotating gently, and record the date and time.
How many units of Botox do I need?
It depends on the area and is decided by the treating provider, not by a calculator. For reference, the Botox Cosmetic label lists 20 Units for glabellar lines, 24 Units for lateral canthal lines, 40 Units for forehead lines with glabellar lines, and 26, 31 or 36 Units for platysma bands. Each other product's label lists its own approved dose.
What is the Botox dilution chart for a 100 Unit vial?
A 100 Unit vial gives 100 Units per mL with 1 mL of saline, 50 with 2 mL, 40 with 2.5 mL, 33.3 with 3 mL and 20 with 5 mL. Divide by 10 for Units per 0.1 mL. The Botox Cosmetic label lists only the 2.5 mL row (4 Units per 0.1 mL); the calculator's chart shows the others as arithmetic.
What is the Dysport reconstitution and dilution?
The Dysport label dilutes the 300 Unit vial with preservative-free 0.9% saline: 0.6 mL gives 50 Units per 0.1 mL, 1.5 mL gives 20, 2.5 mL gives 12 and 3 mL gives 10. For glabellar lines it lists 12 or 20 Units per 0.1 mL, and reconstituted product may be kept refrigerated for up to 24 hours.
How do you reconstitute Xeomin, Daxxify, Jeuveau and Letybo?
All four use preservative-free 0.9% saline. Jeuveau is 2.5 mL on its 100 Unit vial; Letybo is 1.25 mL (50 U) or 2.5 mL (100 U); Daxxify is 0.6 mL (50 U) or 1.2 mL (100 U) for glabellar lines at 8 Units per 0.1 mL; Xeomin follows a volume table for 50, 100 and 200 Unit vials. Daxxify can be used within 72 hours; the others within 24.
How many units per mL is Botox after dilution?
Units per mL is the vial Units divided by the saline volume. A 100 Unit vial in 2.5 mL is 40 Units per mL, which is 4 Units per 0.1 mL. Change the volume and the concentration changes in proportion, so always recalculate when the volume changes.
Can I convert Botox units to Dysport or Xeomin units?
No. Each prescribing information states that its Units are specific to that product's assay and cannot be compared to or converted into Units of any other botulinum toxin product. This calculator does not convert between products.
Sources and scope
- Botox Cosmetic prescribing information (DailyMed)
Sections 2.1 to 2.4: dilution Table 2, 24-hour use window, Table 1 recommended doses, non-interchangeability. Label version 10/18/2024.
- Dysport prescribing information (DailyMed)
Sections 2.1, 2.2 and 2.4: 300 Unit vial dilution Table 1, glabellar line dose, 24-hour storage. Label version 10/24/2024.
- Xeomin prescribing information (DailyMed)
Sections 2.1, 2.6 and 2.7: upper facial line doses, Table 5 diluent volumes, 24-hour storage. Label version 07/10/2026.
- Jeuveau prescribing information (DailyMed)
Sections 2.1 to 2.2: 100 Unit vial dilution Table 1, glabellar line dose. Label version 04/28/2023.
- Daxxify prescribing information (DailyMed)
Sections 2.1, 2.2 and 2.4: glabellar line dose, Tables 1 and 2, 72-hour storage. Label version 01/07/2026.
- Letybo prescribing information (DailyMed)
Sections 2.1 to 2.3: glabellar line dose, Table 1 dilution, 24-hour storage. Label version 11/18/2024.
A math aid and a quotation of published FDA label facts. It does not recommend a dose, dilution, injection site or treatment for any patient, and it does not convert Units between products. Confirm against the current product label and your protocol; dosing and treatment decisions belong to the treating provider. Labels change, so check DailyMed for the current version.