I wanted to understand why the sprouts retract, if the original nerve ending is permanently blocked from Botox?

I wanted to understand why the sprouts retract, if the original nerve ending is permanently blocked? I mean, how does it start working again if the Botox has permanently blocked the nerve endings from releasing acetylcholine? Wouldn't the sprouts be needed? Thank you.

Doctor Answers 4

Botox does not permanently block nerve endings

Botox is a protein that prevents nerve ending from transmitting acetylcholine to stimulate muscles.  The botox protein itself is out of your body within a few hours, but it takes about 3 months for the nerve ending to rebuild it's ability to stimulate nerves.  

Toronto Plastic Surgeon
4.9 out of 5 stars 469 reviews

Retracting nerve sprouts from Botox

I am not sure that the terminal ends of the nerves do retract following Botox absorption. 

You may wish to call Allergan directly and ask for their Consumer Information Department for such an answer.

I am also not a Molecular Biologist but my suspicion is that there is terminal nerve end cell signaling that keeps the nerve and muscle fiber synaptically together.

The nerve itself does not die. It continues to make aceytlcholine in packets which stream down to the terminal end. If no Botox is present, the nerve continues to "work". 

I hope this was helpful.

Dean P. Kane, MD, FACS
Baltimore Plastic Surgeon
4.8 out of 5 stars 82 reviews

How Botox Works

Botox is a competative blocker of acetylcholine from the nerves to the muscle. Botox blocks the receptor on the muscle for acetylcholine which prevents it from causing the muscle to contract. With time the Botox molecule gets knocked off the muscle receptor. When that happens the acetylcholine can now access the receptor and muscle function returns. Nothing happens to the nerve or the muscle other than the presence of a blocker between the two. There is, therefore, no need for nerve sprouting or anything else.

Robert T. Buchanan, MD
Highlands Plastic Surgeon
5.0 out of 5 stars 6 reviews

Nerve repair after botox

The action of botox to block the pre-synaptic neuron is a temporary (90 day) action and not permanent.  The nerve sprouts are a late response to the primary neural blockade and retract after the main nerve is repaired. 

Jeffrey P. Edelstein, MD
Chandler Oculoplastic Surgeon

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.