Katie Barnes
Katie Barnes

The science of nails: how they grow & what makes them grow faster

By Katie Barnes | 22 July 2022 | Expert Advice, Feature

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The standard rate of growth of a normal fingernail is between 0.5 – 1.2mm per week, but this differs from one individual to another. On average, this is approximately 0.1mm a day. Is this more than you thought? The rate of growth of the toenail is three times slower than that of the fingernail at an average rate of 1.62mm per month.

Although it may sound like there’s no rhyme or reason to how nails grow, there are a few basic factors that affect the speed of growth.

I used to pick and nibble my natural nails and never noticed just how quickly they grew until I kicked the habit in readiness for my wedding, with the help of builder gel. I also now notice how I need to file my middle nail down more regularly than the other nails.

Have you ever noticed or had a client point out that their nails are different lengths when they’ve returned for a maintenance service? This is because nails, even on the same hand, do not often grow at the same speed. The nails on your dominant hand will grow quicker, as well as those on the longest fingers. The rate of growth differs by around 0.1mm, which can make it quite noticeable from finger to finger.

Interestingly, the rate of growth is three times faster for a bitten nail compared to a healthy nail. This is because biting causes trauma to the nail, stimulating circulation in the nail bed underneath.

The image below shows which fingernails grow the fastest and slowest.

Taken from Doug Schoon’s book, Nail Structure and Product Chemistry, 2nd edition. Image credit: Facebook.com/DougSchoonsBrain

So why does this happen? Let’s think about the purpose of nails – to protect the tips of the fingers and toes. Therefore, it makes sense that the longest nail grows the quickest to ensure protection.

Fingernails require three to six months to regrow completely, and as we have established toenails require 12 to 18 months.  This is because toenails are generally subjected to less trauma than fingernails. Although you may stub your toe here and there, this temporary burst of circulation won’t have a lasting impact.

From the time of year to how old you are, there are several factors that affect how fast nails grow. Although most of these factors are outside of your control, you can help the process along by practicing good nail hygiene. Actual growth rate is dependent upon age, sex, season, exercise level, diet and hereditary factors.  Contrary to popular belief, nails do not continue to grow after death; the skin dehydrates and tightens, making the nails (and hair) appear to grow.

If you feel like your nails are growing unusually slow, or are experiencing any unusual symptoms, it is recommended to seek advice from your GP. Your symptoms may be attributed to to nutritional deficiencies or another underlying condition. Your doctor can help determine why this is happening and advise you on any next steps.

Love Katie B xx