How it works

The whole routine is one 7-minute session per affected nail, once a day. That's it. Below is what's actually happening and how to do it properly, because the preparation matters more than most people assume.

The three steps

1. Trim and file

Wash and dry the foot. Cut the nail as short as is comfortable, then file down any raised or thickened sections with an emery board.

This is the step people skip and it's the one that undermines everything else. Light does not pass through a thick nail plate. If the nail is heavily thickened, a podiatrist can reduce it properly in a single appointment, and doing that once at the start is worth more than an extra month of sessions.

2. Clip on and start

Remove all nail polish and gel — both block light completely. Clip the device over the nail so the LEDs sit directly above the nail plate, then hold the button for three seconds.

Three blue lights will come on. The fourth LED is 910nm infrared and is invisible to the human eye, so a device with three visible lights is a device working normally. This is the single most common support question we get.

3. Leave it for seven minutes

The cycle is fixed and the device shuts itself off. Move to the next nail or stop there.

Most people do this sitting down in the evening. If you have several nails to treat, a session per nail adds up — some customers buy a second device so they can run two at once.

How often, and for how long

Once a day, per affected nail. Twice is not better and won't speed anything up.

How long you keep going depends on how fast your nails grow, and the honest answer is months rather than weeks. A toenail takes roughly 9 to 12 months to grow out completely. The damaged portion of the nail cannot be repaired — it grows to the tip and gets cut off.

What you're watching for is a clear band at the base of the nail, near the cuticle, getting wider each month. Photograph the nail before your first session. Slow change is almost impossible to judge from memory.

Getting the most out of it

• Keep it consistent. Five sessions a week every week beats fourteen sessions in one keen fortnight and then nothing.
• Keep the nail short. File it down every week or two.
• Keep feet dry. Change socks daily, alternate shoes so each pair dries out, and dry between the toes after showering.
• Don't share tools. Nail clippers and files pass infections between nails and between people.
• Treat your shoes too. An antifungal shoe spray reduces the chance of picking the same thing up again.

Before you start

Speak to your GP or a registered podiatrist first if you have diabetes, reduced circulation or sensation in your feet, a suppressed immune system, or if you are pregnant.

Also see a professional rather than starting a home routine if the nail is painful, the skin around it is red, hot or swollen, there is discharge, or the nail has been injured. Those need looking at.

Keravix is a personal care device intended to support the appearance of nails. It is not a medicine and is not intended to diagnose, treat, cure or prevent any disease.