Dr Tom’s Winning Nail Strengthening Formula

Last updated 29 May 2026

As a talented classical guitarist, Dr Tom Cawood’s fingernails are essential to his craft. He shares how he developed a science-backed, wool-based treatment to keep them in top-notch condition.

How many times have you needed a product only to find there’s nothing on the market that suits? It’s a frustrating situation, but in most cases we give up and settle for what we can get. Seldom do we decide to invent it ourselves. 

Unless you’re MAS Member Dr Tom Cawood – a Christchurch general physician by day, but a man of many other projects after hours. To name a few: he’s helped build an IT and software company; was a registered financial advisor; wrote a book about thyroid cancer; and has big plans for an environmental breakthrough (more on that later). His most recent accomplishment, however, is creating something he’s needed since he was a teen. 

As a young lad growing up in Scotland, Tom picked up his dad’s old guitar which had been languishing in a cupboard, and found he had a flair for it. From there, a love of classical guitar blossomed and Tom soon became celebrated for his skills, playing in concerts accompanied by large orchestras. One issue, however, was he needed strong nails to pluck the strings and he couldn’t prevent his own from continually breaking. 

Despite his promise with music, Tom ended up pursuing a career in medicine and eventually moved to New Zealand with his wife and children. His curious nature never waned, and over the years there have been many other projects in the mix. “There are always about 7 things on the go and my attention span is about 5 years max,” laughs Tom. “My wife's job is to try and dissuade me from the ideas that are least likely to be successful. And some of them have been truly awful.”

From medical scare to scientific breakthrough

Perpetually busy with work, family and hobbies, Tom was abruptly stopped in his tracks in 2018 when he suffered a major stroke, stemming from earlier heart valve problems. It was then that he turned back to his original love of guitar to help rehabilitate his brain. But the problem of how to keep his nails long and strong persisted. So he took matters into his own hands – literally. 

Tom wanted to create a nail strengthening formula that would truly work, but first he needed to come up with a way to test it. “One of the things that struck me was that there’s no lab model of a fingernail, so how are you going to show that it works?” 

Determined to create a solution backed by science, Tom began researching keratin, the protein nails are made from, and found there were quite a few studies coming out of nearby Lincoln University. So with his usual enthusiasm, he gave them a call. “Luckily they agreed to see me, though I’m sure they were thinking, ‘Who is this random guitar-playing dude?’”  

After much discussion between Tom and the university scientists, the team developed an audacious plan to develop a giant fingernail. They would then divide it into smaller pieces and measure breaking force, providing a cost-efficient way to continually tweak and test the strengthening formula until they got it right. A Callaghan Innovation grant helped support the research and, over time, the team produced a formula that included a special blend of hydrolysed keratin from sheep’s wool that made the lab nails 78% stronger in 2 weeks.  

They then shared the formula with a range of human testers. Some were Tom’s mates from the Christchurch Guitar Society and others were people who used their hands professionally – a hairdresser, a farmer and a house renovator, to name a few. There was more trial and error and the odd research challenge until 100% of respondents saw significant improvement.

What’s next for Dr Tom?

Now Tom’s on another learning curve: How to market and sell a new cosmetic product, with proven credentials, to the masses. “I thought the science behind it and the consumer studies would be what mattered to people,” says Tom. “But it turns out almost nobody reads that part!”  

With Dr Tom Nailcare on its way to selling well in New Zealand, the next stop is to conquer the Australian and European markets. Yes, Tom wants to help everyone have stronger nails, but he’s keen to build funds for his next plan, too. Once again, it’s linked to his personal passions, though on a somewhat grander scale this time.  

As a keen tramper and fisherman, Tom is on a mission to help eradicate the invasive alga, didymo, that is disrupting South Island rivers. “If I could make a difference and potentially help control or even eradicate it, that would be fantastic,” he says. “I’ve already persuaded the key scientists in the area to get involved and we have some ideas how we might do it.”  

If Tom’s track record is anything to go by, it sounds like we best stay tuned.

Tom’s MAS moment

Eleven years ago, Tom’s life was turned upside down when he discovered, by chance, that he had a congenital heart problem. “One day, my wife, who is a GP, was resting her head on my chest and heard a funny sound. That sound turned out to be a very damaged bicuspid aortic valve that was no longer functioning.”  

As Tom was preparing for open-heart surgery to replace the valve, he was fearful of the outcome and the financial burden that could potentially be placed on his family if he couldn’t work. Thankfully his Income Security Insurance with MAS helped alleviate that part of the stress during a terrible time.  

“It was the reassurance of knowing I could put that worry on the back burner for now that made a difference,” says Tom. “Psychologically, it was one less thing to worry about when the world was falling down.”