How lignin from wood could make sunscreen safer and stronger

Many of us put on sunscreen assuming it is an uncomplicated good - but have you ever paused to consider whether the very product meant to protect your skin might bring worries of its own?

Dermatologists have long stressed that sunscreen remains our best defence against skin cancer as well as the misery of severe sunburn.

Even so, a recent survey in the United States reported that 14 per cent of young adults think applying sunscreen daily is actually more harmful than exposure to the sun.

A big driver of that uncertainty is research highlighted by the US Food and Drug Administration (FDA), indicating that certain widely used chemicals in these lotions can pass through the skin and be detected in the bloodstream.

Although researchers have not shown that these ingredients are unsafe, the findings have intensified efforts to develop approaches that feel more natural and potentially safer, while still keeping skin properly protected.

Lignin from wood may protect skin

To find an alternative, scientists are turning to the forest for an unexpectedly advanced solution. Their attention has landed on lignin, a naturally occurring substance that could underpin a new generation of skincare.

In plants, lignin functions like a binding agent within cell walls, helping to hold everything together and giving tree trunks their remarkable strength.

But lignin is not only structural. It also acts as a built-in barrier, helping plants withstand intense ultraviolet radiation.

Because lignin is already a natural component of wood, researchers think it may prove gentler for both our bodies and the sensitive coral reefs in the sea.

That environmental angle matters: some sunscreen chemicals can rinse off during swimming and cause harm to marine life.

Extracting lignin from wood

Historically, lignin has been difficult to use in beauty formulations because it tends to look dark. Conventional extraction methods relied on harsh chemicals that left lignin almost black.

It is hardly appealing to smear a dark, sticky sludge on your face before a day at the beach. However, two independent research teams at the South China University of Technology have recently shown how to avoid that problem.

One team, led by Jun Li, used a technique combining milling with ultrasonic waves to obtain a pale yellow lignin from poplar wood.

A second team, led by Yong Qian, achieved a pale pink lignin from birch wood using a similarly gentle approach.

How lignin sunscreen performed

With these lighter extracts in hand, the researchers converted the lignin into nanoparticles - extremely small particles - and blended them into plain white creams to test performance.

The cream containing yellow lignin reached an SPF of 20, while the pink-lignin formulation achieved an SPF of 19. Both provided broad-spectrum protection, meaning they blocked both UVA and UVB rays.

In tests, the creams felt smooth and were easy to blend into light skin tones. An SPF of 20 is an encouraging starting point, but it still falls short of the SPF 50+ products many people commonly buy.

A boost in sun protection

The researchers then aimed to pair lignin’s natural benefits with established sunscreen filters, including avobenzone and octinoxate.

Their approach was to encapsulate these chemicals inside lignin nanoparticles, effectively forming a protective shell around them. The impact was dramatic: the SPF rose to more than 180.

Even though manufacturers cannot legally label sunscreens above SPF 50+ because of how protection is measured, the result indicates that lignin could make sunscreen exceptionally effective.

The benefit is not limited to blocking sunlight. This shell can also extend how long the product works, because lignin helps prevent the other ingredients from breaking down when exposed to heat.

Safer for people and the planet

The most striking aspect of this wood-derived approach is what it could mean for human safety.

By enclosing common sunscreen chemicals within lignin nanoparticles, the researchers found the ingredients no longer soaked into the skin.

That keeps them at the surface - where the lotion is meant to do its job - rather than allowing the substances to enter the bloodstream.

One lignin-nanoparticle sunscreen is now being evaluated in human trials. To date, it appears safe and provides strong UV protection.

These early findings are reassuring for anyone worried about chemical absorption as well as environmental effects.

Natural materials can improve sunscreen

Wood may be delivering a major advance, but it is not the only natural source being explored.

Scientists are also examining materials found in seaweed, ferns, squid and even human hair, searching for additional ways to block UV radiation.

The broader ambition is to create sun-protection products that people can apply every day without lingering concerns about their health.

As researchers learn to harness substances already present in nature, we move towards sun protection that is straightforward, effective and safer for both people and the planet.