Botox is a non-surgical cosmetic procedure that is normally used to improve the appearance of crow’s feet, wrinkles and frown lines. It can also give the lip a fuller appearance a term which is called Botox lips. Botox is a medical product and consequently, it does expire as would be the same with any medicine.
There will always be an expiration date on the package and this typically will be around 2 years. Once the Botox has been mixed with saline, it is generally recommended to use it within 4 hours. However, it is thought that it will probably maintain its potency for up to about 2 weeks following mixing. Most practitioners will generally mix the Botox to the correct concentration and then use it all the same day.
As to whether Botox wears off then this is a completely different answer altogether. Generally speaking, Botox normally lasts around 3-4 months but this may be longer if you are having the procedure repeated. It is important to realise this when calculating the price as it is not a one-off outlay.
The results are generally speaking extremely impressive which is why the procedure is so universally popular. However, your appearance will return to what it was prior to treatment once the Botox has worn off.
For more information on how long Botox lasts you can read this helpful guide.