Whitening strips: what the before and after really looks like
Strips work. They work less dramatically than the photographs suggest, and the gap is mostly photography rather than dishonesty about the product.
Last reviewed 18 September 2026
Why the photos can't be trusted — including honest ones
Four things change how white a tooth looks in a photo, and every one of them moves the image more than a whitening course does:
- Colour temperature. Warm indoor light makes teeth look yellow. Daylight or a cool ring light makes the same teeth look white. Shooting "before" in a bathroom and "after" by a window produces a transformation with no treatment involved.
- Exposure. Brightening an image lifts the whites first. A slightly overexposed after-photo does much of the work.
- Lip retraction. Retractors expose more of each tooth, including the whiter middle portion, and change the surrounding colour your eye compares against.
- What's next to them. Teeth look whiter against red lipstick or a tanned face. Genuinely — the comparison your eye makes is relative.
This applies to real users too, not just brands. Someone posting a genuine result is usually taking the after-photo deliberately, in better light, feeling pleased. The before was a casual snap. Neither is dishonest, and the pair is still not a controlled comparison.
What to actually expect
A full course of over-the-counter strips generally produces a change of roughly two to four shade tabs. In practice that means:
- You will notice it in the mirror, particularly in the first week after finishing.
- A side-by-side photo will show it if both were shot the same way.
- Most people around you won't comment unless they're told. This is the expectation gap that produces disappointed reviews.
Bear in mind shade guides are not a linear scale, so "four shades" means different things depending where you started — a darker starting point moves further on the guide for the same treatment.
When strips underperform, and why
| Situation | What happens |
|---|---|
| Crowded or rotated teeth | The strip bridges over rotated surfaces, leaving untreated patches where it doesn't contact |
| Crowns, veneers or bonding in front | They don't change colour — you can create a visible mismatch |
| Yellowing from thin enamel | Very little effect; the colour is dentine beneath, not stain within the enamel |
| Heavy surface stain | Underwhelming — a cleaning first would have done more |
| Grey rather than yellow tones | Grey generally lifts less than yellow |
Photograph your own properly
If you want to know whether it worked, make the comparison controlled:
- Same light, same time of day, same spot. Pick one and reuse it.
- Lock the white balance if your phone allows it, or shoot both in the same daylight.
- Include a fixed reference — the same white card or plain white shirt in frame both times. This is the single most useful trick, because it gives you something that shouldn't change.
- Same expression and distance. A wider smile shows different teeth.
- No filters, no editing, including automatic beautification, which many phones apply to faces by default.
Take the before photo before day one. Everyone forgets, and then has nothing to compare against but memory — which is exactly what makes results feel disappointing.
Getting more from the same box
- Cleaning first. Strips spent on removable surface stain are wasted.
- Dry the teeth before applying. Better contact, better result.
- Press the strip into the gaps rather than leaving it flat across the front.
- Finish the course. Results are cumulative and most people stop early once they see something.
- Avoid staining food and drink for a few hours after, while teeth are briefly more absorbent.
Read next
Sources
Consulted while writing this page. Listing a source is not an endorsement by that organisation or clinician, and none of them reviewed this page.
- American Dental Association Whitening — Oral Health Topics
- ADA MouthHealthy Teeth Whitening
- Cleveland Clinic Tooth Discoloration: Causes & Treatment