You should replace an electric toothbrush head about every 3–4 months in normal use, and sooner if it looks worn or you’ve been sick.

Quick Scoop

  • Typical schedule: every 3–4 months for most adults using the brush twice a day.
  • If you press hard, have braces, or brush more than 2× daily: every 2–3 months is safer.
  • After a cold, flu, COVID, or stomach bug: change the head as soon as you’re better to reduce reinfection risk.
  • For kids’ electric brushes: about every 2 months because they’re rougher on bristles and hygiene is trickier.
  • Golden rule: if bristles are frayed, splayed, or faded, change the head even if it’s been less than 3 months.

Why the 3–4 month rule?

Electric toothbrush bristles slowly wear down and bend, which makes them much less effective at removing plaque even if they still look okay at a glance. Over time, old bristles can also hold more bacteria and may irritate your gums instead of gently cleaning them.

Many dental associations and big brush brands echo the same guideline: replace the head (or manual brush) roughly every three to four months. That’s based on how long bristles usually stay effective with twice-daily brushing.

Situations when you should change it sooner

  • You’ve been sick: Any contagious illness (respiratory or stomach) is a good reason to swap the head immediately afterward.
  • Bristles look frayed or splayed: If they’re bending outwards or feel rough, the head is past its prime, even if it’s only been a month or two.
  • You brush very hard: Heavy pressure wears bristles faster, so 2–3 months is more realistic.
  • You notice bleeding or irritation: A worn head (or using too much force) can aggravate gums; a fresh, soft head plus gentler pressure can help.

Some modern electric brushes have indicator bristles that fade in color to signal it’s time for a change, which is a handy visual reminder.

Little “routine” you can follow

  1. Note the date when you put on a new head (or set a 3‑month reminder on your phone).
  2. Check the bristles under good light once a week.
  3. Replace immediately if you’ve just recovered from an illness or the bristles look flared out.
  4. For kids, assume a shorter cycle and check even more often.

A simple example: if you start a new head on March 1 and brush twice a day, plan to change it around June 1—but move that earlier if the bristles look worn or you get sick in between.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.