Since Botox is a Toxin, Can it Cause and Outbreak of My Herpes?

The botulinum toxin would not cause a herpes flare. Herpes simplex virus may be awakened from its dormant phase by stress, fatigue, illness, sunburn, trauma, laser resurfacing, chemical peels, dermabrasion, and the placement of needles (for fillers or Botox). 

If there is an area that is going to have Botox injected and that's the very area that you tend to get herpes outbreaks in, then you can ask your doctor about taking an antiviral medication before, during and after the injections.

The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice.  The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs.

Unless you're having your lips injected with filler or Botox around your mouth, the potential for you having an outbreak is very low. If you're overly anxious about the treatment in general, start an antiviral prior as a preventative measure.

This is highly unlikely especially if you are not having any treatment around your mouth. However, triggers for Herpes outbreaks are vaguely understood. Depending upon the frequency and severity of outbreaks, you could use antivirals around the time of treatment to minimize your risk. I hope this information is helpful.Stephen Weber MD, FACS

While it's unlikely for you to have a herpes outbreak after Botox injections, it's wise to be proactive. You can be prescribed Zovirax or Valtrex to be taken before your injections.

Treating your forehead and crow's feet with Botox would not cause an outbreak of your herpes unless you were very stressed or anxious about your treatment.  In that case, it would be the stress that caused the outbreak..  If you are concerned, start taking an oral antiviral medication such as Valtrex the day before your treatment and continue it for a few days afterwards.