I personally think the only way a doctor should charge for Botox is by the unit. The only way to legally purchase Botox in the United States is per unit. Meaning, most doctors purchase a 100 unit bottle of Botox from Allergan - the only make and distributor of Botox in the U.S. The bottle requires 'reconstitution' in order to be used properly. This means that the doctor has to add saline (salt water) into the bottle in order to create a solution of Botox that can then be injected. If you add, for instance, 4 cc (milliliters) of saline into the bottle, you then get a solution that has 25 units per cc. If you add 10 cc of saline into the bottle, you get a solution that is 10 units per cc. Most doctors use a 1 cc syringe to inject Botox. Unfortunately, one syringe in one office is not equivalent to one syringe in another office. Using our examples note above, one syringe in the first office would be equivalent to 25 units of Botox. In the second office, this would be equivalent to only 10 units of Botox. So changing the dilution of Botox can significantly effect the amount of Botox that is actually being given in one syringe. The only measurement that really matters when it comes to controlling unwanted muscle movement is how many units were used. This is also the only consistent factor between offices. So from a patient's perspective, you should only be concerned about how many units are being used in your particular situation. In the San Diego area, Botox can range in price from $8.00 - $17.50 per unit. There shouldn't be any difference in the effectiveness of one unit of Botox from one office to another. Charging patients by the unit of Botox used is a much more transparent method than charging them by the number of syringes used or areas treated. This is the only way for patients to reliably compare apples to apples when it comes to Botox use.