Botox should be injected directly into the muscle as directed by a doctor. Contact a doctor for correct dosage as it will depend on the condition being treated and the patient�s response to the treatment. The injection can be given into more than one area at a time depending on the patient�s condition. The injection should only be given by a trained medical professional, even when used for cosmetic purposes. The medication may take up to 2 weeks after the injection before symptoms begin to improve.