Botox causes muscle atrophy over long term use, is this true?

I think its important to separate a few things here, to be clear.  Muscle Atrophy you can see and that you can not see. Botox works by preventing the muscles from contracting. If you think about any muscle in the body, if you don't use it, you loose it. If you had a cast on your leg, after 6 weeks when the cast comes off, your cast leg will have muscle atrophy compared to the healthy leg. However, with physio and physical activity, the muscle comes back.  We also use Botox sometimes to help with this, like in the Masseter Muscle of the jaw. The same is true for Botox. The mechanism of Botox is to prevent muscle motion and thus by its very nature, you are going to get atrophy of the muscle (or, muscle volume loss). This can be desirable in some people as that means you may need lower doses of Botox in the future as there is less muscle. However, the muscles that control facial expression are so small and thin, muscle loss doesn't really show up. However, to say it doesn't cause atrophy isn't true, but it likely doesn't cause any 'visible' atrophy. Dr James Bonaparte

The only time Botox creates the reverse effect and makes a patient look older is when it has been over-injected or injected into the wrong muscle. This should never happen if you find an expert injector.
While Botox does relax muscles and, over time, they may lose tone and therefore require less treatment to stop them from contracting fully, they do not actually atrophy significantly. I have many patients who have been using Botox for decades and it still continues to rejuvenate their faces. I hope this helps.

Botox is a neuromodulator that relaxes dynamic muscles so that they stop pressing the skin into wrinkles and creases. The operative word here is “relaxes.” We give just enough Botox to let the skin smooth out, but not enough to paralyze the muscle to the point where it would atrophy from lack of use. While over the long term, you may need less Botox because the muscle no longer can contract as strongly as it did, this is a good thing. And while the contractions aren't strong enough to reinforce a wrinkle, they are strong enough to keep the muscle agile. While it may be slightly smaller over the long term, it will not droop or cause an aging look. Please consult a board-certified dermatologist who is an expert in using Botox over the long term to manage aging.

No, Botox won't make you look older or make the muscles atrophy. Botox can actually prevent new lines and wrinkles from forming. Botox results last 3-4 months in new areas of treatment. See an expert for a formal evaluation. Best, Dr. Emer

The simple answer to your question is yes. Prolonged use of botox can cause some degree of muscle atrophy. It’s good to think about facial muscles as you would any type of muscle in your body. If you don’t use or work out your biceps, they tend to shrink. Facial muscles however are much thinner in comparison to other muscle sin the body so atrophy is rarely apparent. 

Botox prevents nerve signals getting through to muscles - in so weakening them.  If Botox is used on a regular basis, the muscles will go through a lengthy time of not working and therefore will undergo some wasting or atrophy.  This is not a bad thing if the muscles in question are those you want to wekame  in order to smooth wrinkles. Long term Botox use is also likely not to be even noticed and would simply result in lower doses of Botox being required to treat the areas of concern.  If the muscle that causes you to frown develops atrophy then it would probably be beneficial.   

Yes, Botox may cause a treated muscle to atrophy slightly over time, but this is not clinically significant. Treated properly, the muscle will still be able to contract somewhat and maintain its tone. Certainly it will not atrophy to the point where it begins to cause facial sagging. Botox has been used successfully as an anti-aging regimen for more than 30 years. Please visit a board-certified dermatologist for a consultation to find out how Botox can help you take aging under your control.

Unless a patient has specifically requested a “frozen” look to their face (a rare occurrence, but it does happen), an expert Botox injector will always administer just enough Botox to a muscle that it relaxes without ceasing to work. While it will no longer push your skin into folds and wrinkles, it will still be able to move so that you can make normal facial expressions. Because it is not contracting fully, there will be a slight degree of atrophy, but it will not be significant. 
Botox is a wonderful long-term anti-aging treatment that can keep you looking younger for many, many years. Consulting a board-certified dermatologist who is expert in using Botox as an anti-aging agent will help you decide if it's the right treatment for you.

You don't have to worry about Botox atrophying your muscles if you use it long term. Your muscle would have to be out of use completely to atrophy enough to start drooping. Botox still lets them “flex” – just not enough to cause a wrinkle. A board-certified dermatologist who has expertise in using Botox to control aging will be able to answer any concerns about Botox in an in-person consultation.

Thank you for your question. Yes, some muscle atrophy can be seen with long term use of Botox. Because if this a lower Botox dose may be required for future injections. I recommend having a consultation with an expert injector to discuss your concerns and determine the best treatment plan for you. Best of Luck!