How Long Before Botox Completely Wears Off?

It's unlikely that Botox injected 5 months ago is still having any effect. Botox results typically last about 3-4 months with slightly longer durations capable in situations where the patient is consistently using the product.
If it looks or feels like the Botox is still active, it may be because muscles that are relaxed with repeated Botox usage can weaken. This in turn means you need less Botox for the same effects or can go slightly longer between treatments.

Botox typically lasts for about 3-4 months. You might see results last longer if you've had many treatments performed before or if the area you have treated isn't moved a lot. You should probably see your injector to talk about your results.

Because you've had injections before and have relaxed the muscles in the area previously, these current results may last a bit longer than the typical 3-4 months. However, rest assured that if you wait it out a bit longer, your results will gradually disappear.

Dear nndoll
Theoretically, all of the neuromuscular junctions blocked by Botox are replaced by 4 months. However, so of the effect that we see clinically is due to muscle atrophy and some of the effect is due to muscle retraiining. As a result, even though Botox is theoretically no longer present, you still are seeing the effects of treatment, However, there effects will eventually also resolve. I have patients who tell me at three months they need retreatment and others who feel that they have Botox results for a year. We do not send out reminder cards for Botox. I let the mirror do the talking. People return when the notice the effects wear off and this time frame is a little different for everyone.

Your question is an interesting one. Unlike dermal fillers, which must stay around to maintain the effect, Botox is actually gone in a matter of days. What is does is disrupt the connection between the nerve and the muscle, causing the relaxation effect. It takes about 3-4 months for the body to re-establish the connection, so it is this recovery process and not the longevity of the Botox itself that determines the duration of action. If you are still seeing the effects at 5 months, I can't imagine it taking much longer.