How long do Botox injections for wrinkles last?

On average, Botox lasts about 4 months, and then, within 2 weeks, your scowl returns with a vengeance. So, I certainly recommend "dosing up" just before the effect dissipates.

You'll be happy to hear that a new study has found that if you use Botox every 4 months for 2 years, the muscles weaken so much that they begin to take longer to recover. And so after 2 years, most people can lengthen the time between injections to 6 months. And while there isn't any data yet, my bet is that when you hit 4 or 5 years of continuous Botox, that wrinkle-killing drug will last nearly a year.