There’s something about a gel manicure that just makes you feel like you’ve got it together. The shiny finish, the knowledge that they’re not going to immediately chip during basic everyday tasks (unless you’re really unlucky)… Your life might be falling apart. But your nails? Impeccable.

But the reality might not be quite as glossy. Over the past few years, a spate of headlines and studies have called out various gel nail ingredients as potential red flags for our health. Most recently, those headlines have centred around one specific ingredient, TPO, which is being phased out in the UK. So how worried do we need to be about our favourite beauty habit?

Trimethylbenzoyl diphenylphosphine oxide, mercifully shortened to TPO, is a photoinitiator, a chemical compound that absorbs the light emitted by a UV or LED nail lamp to kickstart the reaction involved in the photocuring process. This hardens the polish and gives the glossy, durable finish that sets gels apart from a traditional manicure (conventional nail varnish doesn’t include TPO, because there is no curing reaction involved in the process – you simply wait for the polish to dry).

It’s been particularly popular in gel polishes because it absorbs light across a wide range of wavelengths, so it works well with various nail dryers. So what’s the issue here? Research on animals has shown that high levels of exposure to TPO could be dangerous to fertility and embryonic development. In 2020, one study found that male rats underwent “massive” changes to their testicles, as well as reduced fertility, while females experienced disruption to their reproductive cycle; another lab study found it to be toxic to human cells.

TPO has since been categorised as a category 1B reproductive toxicant under European Union and UK regulations. It’s important to note that this is very much a precautionary measure. In these studies, the animals and the human cells were exposed to much, much higher dosages of TPO than you would be while getting your nails done; the research on rats, for example, relied on large, repeated doses ingested over an extended period of time. Plus, the photocuring process means that the actual amount of time you’re exposed to TPO is relatively brief; it is consumed by the chemical reaction.

Still, acting out of caution, the European Union banned TPO in September last year, and the UK has now caught up. As of 15 August, manufacturers can’t launch any new products onto the market that feature TPO as an ingredient. Pre-existing products, though, will still be available for salons to purchase and use until 14 February next year, when they won’t be able to buy more stock.

What does this mean for your manicure, then? In truth, it won’t change things much. “There are already TPO-free gel formulations available, which use alternative photoinitiators such as TPO-L to cure the gel under UV or LED light,” explains Dr Derrick Phillips, a consultant dermatologist. Indeed, many salons are already using them – and the wide availability of alternative products was a factor in the ban.

There should, Phillips adds, “be little noticeable difference in the finish, durability or overall quality of a well-formulated TPO-free manicure” – and you might already be going TPO-free without even realising it. And if you’re worried, you can just ask your nail technician about the ingredients.

But concerns around gel manicures go beyond TPO. That’s because the photoinitiating process also involves a UV or LED light that emits low levels of UVA radiation, which is linked to a higher risk of cancer.

A study published in Nature Communications in 2023 exposed mouse cells and human cells to UV nail dryers for 20 minutes, and found that between 20 and 30 per cent of the exposed cells died; with three consecutive 20-minute sessions, between 65 and 70 per cent died. The scientists from the University of California San Diego also noticed mutations with the same patterns as those seen in skin cancer patients.

Again, though, we should bear in mind that cells in a lab are more vulnerable to damage than the skin cells on our hands – and the authors noted themselves that a long-term study would be needed before we can conclusively determine whether these devices lead to an increased skin cancer risk.

“The evidence specifically linking UV nail lamps to skin cancer remains limited,” Dr Phillips says. “Current research suggests that prolonged and repeated exposure may pose a low risk, although the available evidence is weak. As UV damage is cumulative, I would still recommend minimising unnecessary exposure, particularly for people who have gel manicures frequently.”

To do so, he suggests applying “a high factor, broad spectrum SPF to the hands before a gel manicure, or wearing dark, opaque fingerless gloves” – it probably makes sense to pop these on before any polish is applied, just to avoid smudges.

Other ingredients to be wary of are acrylates, which help to bond the varnish to your nail for that long-lasting finish; one of the most popular is known as HEMA, short for hydroxyethyl methacrylate. “When the gel is placed under a UV or LED lamp, these chemicals react to form the hard, durable coating of a gel manicure,” Dr Phillips says.

Acrylates like HEMA have caused concern because they can trigger allergic contact dermatitis, a skin condition that results in painful, itchy, dry skin around the fingers and nails, and potentially on the eyelids and face. It can also cause swelling, which might prompt the nail plate to loosen from its bed.

In 2018, the British Association of Dermatologists warned that acrylates were causing a spike in contact dermatitis tantamount to an “epidemic”, with an estimated 2.4 per cent of people affected. And a few years later, in 2023, the Office for Product Safety and Standards launched a formal investigation.

The problem arises when uncured varnish containing acrylates comes into contact with the skin and triggers an immune response. This is more likely to happen when the product isn’t applied properly, whether that’s by amateurs using at-home kits or by salon staff who haven’t been properly trained.

There are “wider implications”, Dr Phillips says, because acrylates are “also used in some dental materials, medical adhesives and the bone cement used in certain orthopaedic procedures, including joint replacements”. Once you’ve become sensitised, future contact with these chemicals might trigger a reaction again – so you could be setting yourself up for a lifetime of issues.

Products containing HEMA aren’t banned outright, but they are restricted to professional use. An at-home gel kit, then, should already use HEMA-free polish – but dermatologists and manicurists tend to recommend that you sidestep these altogether and just see a qualified professional.

It’s important, Dr Phillips adds, “to avoid getting gel on the surrounding skin and to make sure the product is fully hardened under the appropriate lamp” – sometimes the lamps in bargain kits are lower wattage, and won’t properly harden the gel.

Essentially, he says, “occasional gel manicures are unlikely to pose a significant health risk for most people”. But if you’re getting a new set of gels every few weeks or so, it’s definitely worth asking your technician about the products they’re using, and taking precautions wherever you can. Sure, fingerless gloves might not be the most fashionable accompaniment to your manicure, but skin health is never going to go out of style.