Can Botox lead to loss of smell and taste?

No, it is unlikely that Botox caused a loss in smell and taste. If it persists, I recommend following up with your Doctor for a formal evaluation. Best, Dr. Emer

I have never heard of a patient's smell or taste being affected by Botox. I would suggest that you get thoroughly checked out by your physician to rule out any other causes. Best of luck.

I'm sorry to hear that you're noticing these symptoms after your Botox treatment.  The effects of Botox at cosmetic dosages are highly localized, and are typically limited to the individual facial muscles being treated.  To the best of my knowledge, loss of taste and smell have not been reported as side effects in any major Botox clinical trials, and in my personal experience, I've never had a patient who developed these symptoms after Botox.  I would recommend following-up with your plastic surgeon and your primary care doctor to discuss your concerns.  I hope you feel better soon.

This is not a reported side effect of Botox so that if you and your surgeon feel that it is an issue then report to Allergan

in my 22 years of using BOTOX routinelyI have never had a patient who complained of a similar problem. You should have your physician contact allergen and report this as a possible side effect that must be looked into. Good luck from New York City

Thank you for your questions, and I have not heard of this side effect. But I
would recommend you contact Allergan and see if they have any reports of
this specific type of side effect, but it may be coincidental or caused by another medication or issue. 
Benjamin J. Cousins MD
Board Certified Plastic Surgeon

I have not heard this from my patients.  I do all of my own injections so I am curious about this.  How does it change your sense of smell and taste.  Do you take any other medications or other the counter supplements?

I have never heard of this before.  I would recommend that you notify the plastic surgeon who performed your injections of your concerns.  They should be able to contact Allergan concerning this matter.  All of the Best,Dr. John Serrao