# How long does Invisalign take to straighten teeth?

Source: https://thelocaldentist.co.uk/answers/how-long-does-invisalign-take/
Updated: 2026-07-13

## Quick answer

Most Invisalign treatment takes 6–18 months, though simple cosmetic adjustments can finish in as little as 3 months and complex bite corrections can take 2 years or more. Your dentist or orthodontist gives an individual estimate after assessing your teeth. Retainers are needed afterwards to stop teeth drifting back.

## Key facts

- Typical range: 6–18 months for most adult cases
- Simple cosmetic cases: sometimes 3–6 months
- Complex bite or crowding cases: can take 18–24 months or longer
- Wearing aligners for 20–22 hours a day as instructed keeps treatment on schedule
- Retainers are required after treatment to hold the new position long-term
- Fixed metal braces cover a similar or slightly wider range of cases and timelines

Editorial content from The Local Dentist — not clinical advice.