Anti-wrinkle injections are small doses of a prescription-only medicine, botulinum toxin type A, injected into specific facial muscles so they contract less. With the muscle relaxed, the skin above it stops folding into lines when you frown, squint or raise your brows. The effect appears within days, lasts three to four months, and then wears off.
What is actually in the injection?
The medicine is botulinum toxin type A, a purified protein made by a bacterium and used in medicine since the late 1980s. In the UK it is licensed under several brand names and is a prescription-only medicine, which means a doctor, dentist, nurse prescriber or pharmacist prescriber must assess you and prescribe it before anyone can inject it.
The dose used for lines is tiny and measured in “units”. A typical frown-line treatment uses somewhere between 10 and 25 units, which is why the same medicine that treats muscle spasm in hospital is safe to use on the face in a clinic setting.
Because it is prescription-only, UK advertising rules do not allow clinics to advertise the medicine itself to the public. That is why clinics, and this site, talk about “anti-wrinkle injections” rather than naming the product. The treatment is the same.
How do they work?
When you frown, a nerve sends a signal to the muscle between your brows and the muscle contracts, folding the skin into vertical lines. Over years the folding leaves a crease that is there even when your face is at rest.
Botulinum toxin blocks the signal at the point where the nerve meets the muscle. The muscle still exists and still has blood supply; it simply receives a weaker instruction to contract. The skin above it relaxes, existing lines soften, and new creasing slows down while the medicine is active.
The block is temporary. Over about three months the nerve grows new connections to the muscle, the signal returns and so does the movement. That is why the treatment is repeated rather than permanent.
What lines can be treated?
The treatment works on “dynamic” lines: lines caused by muscle movement. The three areas with the longest track record and the most evidence are:
- Frown lines between the brows (glabellar lines), the only cosmetic area for which the medicine holds a formal UK licence.
- Forehead lines, the horizontal lines when you raise your brows.
- Crow’s feet, the lines fanning from the outer corners of the eyes when you smile or squint.
Practitioners also treat bunny lines on the nose, a gummy smile, chin dimpling, downturned mouth corners, neck bands, and the masseter muscle of the jaw for teeth grinding or jaw slimming. These are “off-label” uses, which is legal and common in the UK when a prescriber judges it appropriate, but it means the evidence base is smaller and the consultation matters more. Our guide to the masseter and jaw explains the most popular of these.
Lines that are present when your face is fully relaxed (“static” lines), sun damage, sagging and loss of volume do not respond well to anti-wrinkle injections alone. A good practitioner will tell you this at consultation rather than treat you anyway.
What happens at a consultation?
By law, a prescriber must assess you before the medicine is prescribed. Since 1 June 2025 the Nursing and Midwifery Council requires nurse prescribers to do this face to face, not by video call, and the Joint Council for Cosmetic Practitioners advises the public to expect a face-to-face consultation with the prescriber. If a clinic offers to treat you on your first visit with no sign of a prescriber, that is a reason to walk away.
A proper consultation covers:
- Your medical history, medicines, allergies and whether you are pregnant or breastfeeding (treatment is not given during either).
- What bothers you and what result you want, including a frank conversation about what the treatment can and cannot do.
- Examination of how your muscles move, often while you frown, raise your brows and smile.
- The risks, side effects and aftercare, and your written consent.
- Photographs before treatment, so results can be compared.
You should leave knowing the practitioner’s name and professional registration, who prescribed the medicine, which product and roughly how many units will be used, and what it will cost.
What happens during treatment?
Treatment takes ten to twenty minutes. The practitioner cleans the skin, marks the injection points, and injects small amounts into each muscle with a very fine needle. Frown lines usually take five injection points, the forehead four to eight, and crow’s feet three on each side. You can go back to work straight afterwards.
Expect small bumps at the injection sites that settle within half an hour, and possibly pinpoint bruising. Our aftercare guide covers the first two weeks.
When will I see a result?
Nothing changes on the day. Most people notice the muscle weakening after two to three days and the full result at ten to fourteen days. A good clinic books a review at around two weeks, when a small top-up can be added if one area has under-responded. Our guide to how long the treatment takes to work goes through the timeline day by day.
What are the risks?
Common, short-lived effects are bruising, redness, mild swelling and a headache in the first day or two. Less common effects, usually from the medicine spreading slightly beyond the intended muscle, include a heavy brow, a drooping eyelid (ptosis) or uneven eyebrows. These wear off as the medicine does, typically within a few weeks, and a skilled practitioner can sometimes correct them.
Serious reactions are rare. Difficulty swallowing, breathing or speaking, blurred vision or widespread muscle weakness in the days after treatment need urgent medical attention: contact the clinic and call NHS 111, or 999 if breathing is affected.
The biggest risk in the UK market is not the medicine but who is holding the syringe. Our guide to who can legally give anti-wrinkle injections explains the rules and how to check a practitioner.
How much does it cost?
Across 368 clinics listed on antiwrinkleinjections.co.uk, the typical starting price for one treatment area is £175, with half of clinics charging between £150 and £200 (prices from clinic websites, checked October 2026). Clinics usually price by area, with a reduced rate for two or three areas in one session. The cost guide has prices by city and explains what pushes the price up or down.
Is it worth it?
That depends on what you want. For dynamic lines in the upper face, anti-wrinkle injections have the best evidence of any non-surgical treatment and a very long safety record when given by a trained healthcare professional. For skin texture, sun damage or sagging, other treatments do more. The best next step is a consultation with a registered practitioner who will tell you which of these applies to you.
What are anti-wrinkle injections made of, and how do they work?
The medicine is botulinum toxin type A, a purified protein made by a bacterium and prepared under licence by a handful of pharmaceutical companies, in Ireland, Germany, France and the UK among other places. In the tiny, measured doses used for wrinkles it does one thing: it blocks the signal between a nerve ending and the muscle it serves, so the muscle cannot contract fully. A line that is made by a muscle movement, such as the frown between the brows or the crow’s feet from smiling, softens because the movement that creases the skin is reduced. Lines that are there at rest, from sun damage, smoking or age, soften less, which is why a consultation looks at what is causing each line. The effect wears off as the nerve endings recover over three to four months; nothing is left behind.
Sources
- NHS: Botulinum toxin injections
- UK legislation: Botulinum Toxin and Cosmetic Fillers (Children) Act 2021
- Joint Council for Cosmetic Practitioners: face-to-face consultation guidance
- Professional Standards Authority: check a practitioner on an accredited register
- Department of Health and Social Care: licensing of non-surgical cosmetic procedures in England, consultation response, August 2025