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Toxin, filler or neither: choosing the right treatment

Botulinum toxin and dermal filler solve different problems. A practical comparison of what each does, where they overlap, and when the right answer is neither.

Published by Northbank MediaLast reviewed 2026-07-31 Section 02

The short answer

Botulinum toxin reduces muscle movement, so it treats lines caused by expression. Dermal filler adds volume and structure, so it treats loss of support and shape. If your concern only appears when you move, toxin is the relevant treatment. If it is present when your face is completely still and looks like lost volume, filler may be. If it improves when you lie down, the issue is descent and neither product is a complete answer.

Two products dominate the UK non-surgical market and they are frequently discussed as though they were interchangeable options at different price points. They are not. They act on different tissues, solve different problems and fail in different ways. Choosing between them is not a matter of budget or preference. It is a matter of what has actually changed in your face.

What botulinum toxin actually does

Botulinum toxin type A temporarily reduces the signal between nerve and muscle at the site it is placed. The treated muscle contracts less. The skin folded by that contraction folds less, so lines created by movement soften, and over time skin that is not being repeatedly creased can improve.

It follows that toxin does nothing about volume, nothing about skin texture or pigment and nothing about tissue that has descended. It is the correct answer for the frown complex, for horizontal forehead lines within the limits described in our forehead guide, for lines at the outer corner of the eye and for a handful of specific muscular problems in the lower face and neck.

What dermal filler actually does

Dermal filler adds material. Most products used in UK practice are hyaluronic acid gels, which provide volume, some structural support depending on how firmly the gel is cross-linked, and hydration because hyaluronic acid attracts water. Placed deep against bone, a firm gel can project and support. Placed superficially, a soft gel can smooth a defined depression.

Filler does nothing about movement. Injecting a dynamic line with filler is a common way to produce a result that looks acceptable at rest and strange in motion. It also does nothing for skin texture or pigment, and it compensates for descent rather than correcting it, which has a limit.

Side by side

Botulinum toxin compared with dermal filler
Botulinum toxinDermal filler
What it doesTemporarily reduces muscle contractionAdds volume, structure and hydration
Best forLines that appear on movementLoss of volume, shape and support
Onset3 to 5 daysImmediate, but swelling distorts it
Full resultAbout 2 weeksAbout 4 weeks
Typical durationAbout 3 to 4 monthsAbout 6 to 18 months by product and site
ReversibleNo, it wears offHyaluronic acid can be dissolved with an enzyme
Typical UK cost, 2026About £150 to £350 per areaAbout £250 to £600 per syringe
Main risksAsymmetry, brow heaviness, temporary eyelid droopBruising, lumps, migration, infection, rarely vascular occlusion
Regulatory statusPrescription-only medicineMost are regulated as medical devices

Indicative UK ranges and typical behaviour in 2026. Individual products, areas and practitioners vary, and these figures are typical advertised ranges rather than a survey.

Where they genuinely overlap

A small number of concerns can be approached from either direction, and the choice depends on the individual. Lines at the outer corner of the eye are usually muscular but have a skin quality component. The area under the eye can involve volume loss, skin quality and muscle activity in different proportions in different people. A downturned mouth corner can be treated by reducing the muscle pulling it down, by supporting the tissue around it, or by both.

In those cases the correct approach is assessment rather than preference, and a practitioner who reaches for the same product for every patient is not assessing. Combination treatment is common and reasonable, but it should be a plan rather than an accumulation.

When the answer is neither

Several very common concerns are not addressed by either product.

  • Skin texture, pores and dullness. These belong to the skin layer and respond to resurfacing, microneedling, peels and topical retinoids over months.
  • Pigmentation and redness. These need targeted treatment and, first, a proper diagnosis, since not every dark patch is sun damage. Dermatological assessment matters here.
  • Significant laxity. Once skin and tissue have genuinely loosened, adding volume makes a face heavier rather than lifted. Surgery repositions tissue in a way injectables cannot.
  • Tiredness, puffiness and asymmetry that varies day to day. Sleep, salt, alcohol, allergy and posture change the face substantially, and treating a fluctuating appearance with a permanent-feeling intervention is a route to disappointment.

There is also the group of patients for whom the right answer is a period of doing nothing, because the concern is recent, mild, or was noticed after an hour in front of a magnifying mirror. Practitioners who say so are not turning away business carelessly, they are managing a long relationship.

The risk profiles are different too

The consequences of a poor toxin result are usually temporary and predictable. Asymmetry, a heavy brow or an odd smile resolve as the effect wears off over three to four months. That is unpleasant and it is finite.

Filler carries a wider range. Lumps, migration, prolonged swelling, delayed inflammatory reactions, infection and, rarely, vascular occlusion where product interrupts a blood supply. Vascular events are the reason a practitioner needs an emergency plan, the dissolving enzyme on the premises for hyaluronic acid products, and a phone number that is answered out of hours. Our guide to recognising a complication sets out the warning signs. Suspected adverse events involving a medicine or a device can be reported to the MHRA through the Yellow Card scheme.

Making the decision

Work through it in order. Does the concern appear only on movement? That is muscular. Is it present when your face is completely still, and does it look like a loss of shape or fullness? That is volume. Does it improve markedly when you lie down or lean forward? That is descent, and it is a structural problem with a limited non-surgical answer. Is it about the surface of the skin rather than its shape? That is the skin layer.

The four-layer framework in why faces age is the same logic in more detail. Take the answer into the consultation and ask the practitioner whether they agree with your reading. Their response tells you a great deal about how they work.

No commercial links. This article contains no commercial links of any kind. No clinic, practitioner, manufacturer or agency is named, recommended or linked to, and nobody has paid for, influenced or previewed anything on this page. External links go only to UK regulators and institutional bodies and carry a nofollow attribute. Published by Northbank Media under our editorial policy.

Sources

  1. Medicines and Healthcare products Regulatory Agency, the UK regulator for medicines and medical devices
  2. MHRA Yellow Card scheme, for reporting suspected side effects and device incidents
  3. National Institute for Health and Care Excellence, guidance on clinical and interventional procedures
  4. British Association of Dermatologists, patient information on skin and skin procedures

Frequently asked questions

What is the difference between Botox and fillers?

Botulinum toxin temporarily reduces muscle contraction, so it treats lines caused by movement. Dermal filler adds volume and structure, so it treats loss of support and shape. They act on different tissues and are not alternatives to each other, which is why the right choice depends on what has changed in your face rather than on price.

Can I have Botox and filler at the same appointment?

Many clinics do combine them, and for some treatment plans that is appropriate. It should be a plan agreed after an assessment rather than an accumulation of add-ons on the day, and a practitioner should be able to explain what each product is doing and why both are needed.

Which lasts longer, toxin or filler?

Dermal filler generally lasts longer. Botulinum toxin commonly lasts three to four months. Hyaluronic acid filler commonly lasts six to eighteen months depending on the product, the area and how mobile that area is, with structural placement on bone lasting longer than product in mobile tissue such as the lips.

Which is riskier?

Dermal filler has the broader range of possible complications, including lumps, migration, delayed inflammatory reactions, infection and the rare but serious risk of vascular occlusion. Poor toxin results are usually temporary and resolve as the effect wears off. Both require a practitioner with a written plan for managing problems.

What if neither treatment is right for me?

That is a common and legitimate outcome. Skin texture, pigmentation, redness and significant tissue laxity are not addressed by either product, and they need resurfacing, dermatological assessment or, in the case of laxity, a surgical conversation. A practitioner who says so is giving you better information than one who offers a syringe regardless.

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