Are Botox Results Permanent After Long-term Use?

This really depends on the patient and the concern targeted. It is true that repeated treatments can prolong results, but they may not be permanent and last just a few months longer.

Botox typically lasts for about 3-4 months but with regular appointments you can experience prolonged results so that you no longer have to have appointments scheduled as often as before. This is true for anywhere you have treated. 

Botox usually works for 3 to 4 months.  This depends on the dose, as well as the patient.  If the patient is hyper-metabolic, (i.e. in the gym twice a day) it may last a shorter period of time.  Likewise if a patient is very animated with the muscles of facial expression, this can also decrease the length of effectiveness.

Some will say that with continued use, the muscle will atrophy and one may use less Botox, or come in less frequently.  As of this writing, there are no good medical studies to show this.  Therefore we cannot say that Botox is permanent.

After repeated injections of  Botox, muscles can have disuse atrophy making them weaker. That will reduce the frequency of Botox injections but unlikely to be permanent.
In a way it is a blessing because any severe side effects or complications related to Botox will always be temporary.
Regards

To my knowledge, there are no widely accepted reports of this phenomenon. The muscles may weaken after repeated use but can return to normal after cessation of use.

Unfortunately, I have not seen any data supporting your claim.  Botox typically lasts 3-4 months and it will then have to be re-injected to continue the effect.  I have seen the effect last 6 months, but this is the exception rather than the rule.

BOTOX and Dysport are phenomenal. These botulinum A toxin products are very effective in softening lines in the forehead and around the eyes. This idea that the effects of BOTOX become permanent after multiple treatments is the stuff of urban myth. It is simply not true. If you stop getting treatment the effects will eventually wear off. There is something to muscle retraining which is thought to be why some effects of treatment do seem to last beyond the 4 months that it takes for these treatments to wear off. However, if a doctor is telling you that after 9 to 12 treatments you won't need to get BOTOX anymore, this is not accurate information.

Botox results last 3-4 months on the average but sometimes up to 6-8 months but never permanent. Dysport results may last 3-5 months but also never permanent.  Hopefully, someday we will have something that lasts a year or 2, but not yet.

I wouldn't say that the results become permanent over time, however, and with repeated injections, the lines and wrinkles will become less severe as the muscles are trained to relax.Most patients see improvement within several days of injection. The result will usually last about three to four months at which point the muscle action gradually returns and the lines and wrinkles begin to reappear.

Botox results are only temporary, and typically last 3-4 months for most people.  For those who get injected at regular intervals over time, however, the results can sometimes last a little bit longer, since the muscles have been immobilized for a long period and can atrophy.  That said, once Botox use is discontinued, they will slowly return to how they were initially, prior to treatment.