The hidden health risks of lip fillers

Plump, pouty lips are everywhere – from social media filters to celebrity red carpets. But behind the glossy aesthetic of lip fillers lies a growing concern among medical professionals.

While increasing numbers of people in the UK – often young women – are opting for dermal fillers to achieve a fuller look without surgery, the rise of overfilled “trout pouts” and stiff “duck lips” has sparked a wave of alarm, even among those who might typically support cosmetic treatments.

Lip fillers are far from risk-free – and in some cases, the health consequences are permanent.

Unlike surgical procedures, lip fillers are not legally considered medical treatments. That means they are largely unregulated, and in many cases, are being injected by people with little or no medical training.

This is a problem, because lips are delicate and highly mobile. They contain very little natural fat and rely on a ring of tiny muscles to express everything from joy to concern. Injecting too much filler, or using the wrong kind, can interfere with these muscles – leaving the lips stiff, unnatural, or even immobile.

While some patients seek lip fillers for genuine medical reasons, such as facial palsy or disfigurement, these are exceptions. For most, the health risks can outweigh the cosmetic benefits.

What are fillers made of?

The substances used in lip fillers have changed over time. Older materials such as liquid silicone were eventually phased out due to serious complications, including scarring and migration of the product to other parts of the body.

Today, most lip fillers are made from hyaluronic acid (HA) – a substance that naturally exists in our bodies, particularly in connective tissue. HA attracts water, giving the skin volume and keeping it hydrated. As we age, our natural levels of HA decrease, which is why skin becomes drier and loses firmness.

The HA used in fillers is either extracted from animal tissue, such as rooster combs, or produced synthetically using bacteria. While this modern version is safer than older fillers, it still carries risks including allergic reactions, reactivation of cold sores (herpes simplex virus), infections and inflammation.

There have also been rare, but severe, cases of vascular complications such as blindness and tissue death, when fillers accidentally enter blood vessels.

The risk to kidneys

Less widely known – but equally concerning – is how repeat filler use may affect internal organs, particularly the kidneys.

Hyaluronic acid isn’t just a skin plumper – it also plays a role in the immune system. When the body detects inflammation, such as from repeated filler injections, it can respond by producing HA in the kidneys. This triggers a chain reaction: first, the kidneys produce high-molecular weight HA, which increases inflammation. Later, they switch to low-molecular weight HA, which reduces inflammation but causes fibrosis, or scarring of the tissue.

This double-edged response has been linked to chronic kidney disease and, in severe cases, even renal failure. Researchers are still exploring these links, but the risks become more significant with each repeated injection – especially in people who are genetically or medically vulnerable.

HA can also contribute to the formation of calcium oxalate crystals in the kidneys. These can lead to kidney stones and further tissue damage, potentially causing lifelong complications.

Who should avoid lip fillers?

Given these risks, some people should approach fillers with extreme caution – or avoid them entirely. These include people with a history of kidney problems or allergic reactions to filler ingredients, recurrent cold sores, autoimmune conditions (like lupus or rheumatoid arthritis), diabetes or blood clotting disorders, and women who are pregnant or breastfeeding.

Despite the risks, lip fillers remain widely accessible and heavily promoted – particularly to young people influenced by social media trends. Many undergo these treatments without fully understanding what they’re putting into their bodies.

So, what needs to change? First, better regulation. If lip filler injections were treated as medical procedures, stricter controls could help reduce botched treatments and serious complications.

Second, more education. Patients need to understand that just because something is “non-surgical” doesn’t mean it’s safe. Fillers are still foreign substances being injected into the body. They come with risks – and these risks can increase over time.

Lip fillers can offer subtle, beautiful enhancements when used sparingly and professionally. But when misused or overused, they can lead to lasting disfigurement, loss of function, and even serious internal health issues like kidney damage.

Beauty trends should never come at the cost of your health.

Jim Frame does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.