Short answer
Cosmetic botulinum toxin injections are a prescription-only medicine that temporarily weakens specific facial muscles, softening lines that appear when you frown, squint or raise your eyebrows.15 The effect usually begins within a few days and fades over about three to four months, so it is not a one-off treatment.2 It does little for lines present at rest that come from sun damage, volume loss or skin laxity. Because the cause of a line, the muscles involved and your medical history all differ, an in-person assessment by a trained prescriber is what decides whether it is reasonable at all.
Decision snapshot
| Question | Snapshot |
|---|---|
| What it is | Small injections of a purified botulinum toxin type A product into selected facial muscles |
| Main cosmetic targets | Frown lines between the brows, crow’s feet, horizontal forehead lines |
| Onset | Usually 1–3 days; full effect can take a week or more |
| How long it lasts | Typically about 3–4 months |
| Downtime | Usually minimal; small bumps or bruises may be visible briefly |
| Most discussed risks | Bruising, headache, drooping eyelid or brow, asymmetry; rarely spread of toxin effect |
| UK status | Prescription-only medicine; illegal to give for cosmetic purposes to under-18s in England |
| Evidence for line reduction | Strong (short-term, frown lines) |
On this page
- What it is and how it works
- What may be causing the lines
- Who may be considered
- Alternatives
- Procedure and preparation
- Recovery and results timeline
- How long results last
- Pain and comfort
- Risks and complications
- How strong is the evidence?
- Products, regulation and red flags
- Cost drivers
- Frequently asked questions
- Bottom line
- Sources
What botulinum toxin injections are and how they work
Botulinum toxin type A (BoNT-A) is a purified protein that blocks the nerve signal telling a muscle to contract. Injected in tiny doses, it temporarily stops the treated muscle from moving fully, so the skin above it creases less.1 “Botox” is one brand name; it is often used loosely for the whole group.
Each licensed product has its own generic name. Botox is onabotulinumtoxinA;2 other formulations widely studied for cosmetic use include abobotulinumtoxinA and incobotulinumtoxinA.10 Their doses are measured in units, but the units are not interchangeable between products, so one brand’s dose cannot simply be converted into another’s.2
In the United States, the Food and Drug Administration (FDA) has approved Botox Cosmetic for the temporary improvement of moderate to severe frown lines (glabellar lines), crow’s feet (lateral canthal lines) and forehead lines in adults.2 In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) classes botulinum toxin as a prescription-only medicine.5
What may be causing the lines
Facial lines have several causes, and botulinum toxin acts on only one of them. Repeated expressions such as frowning, squinting and smiling create grooves that can become fixed as skin loses its ability to spring back.3 Other contributors include:
- Ageing skin — less elasticity, less moisture and less fat and collagen in the deeper layers.3
- Ultraviolet (UV) exposure — breaks down collagen and elastin.3
- Smoking and pollution — both speed up skin ageing.3
- Family history — inherited traits shape how skin ages.3
- Volume loss and sagging — folds such as those beside the mouth often reflect structural change rather than muscle movement.
A drooping upper eyelid or heavy brow can also look like “tired” lines, and may have a medical cause worth checking before any cosmetic treatment.
What it may change
- Lines that deepen with movement, particularly frown lines and crow’s feet, which respond best.4
- Horizontal forehead lines, where the dose needs balancing against brow position.
What it will not change
- Lost volume, sagging skin or jowls.
- Sun damage, pigmentation or skin texture.
- Deep lines already etched in at rest may soften only partly.
- Not everyone sees a benefit.1
Who may be considered
A clinician may consider treatment for an adult whose main concern is lines caused by muscle movement, who is in good general health and who understands that the effect is temporary. In England it is a criminal offence to give botulinum toxin for cosmetic purposes to anyone under 18, and parental consent does not change that.11 Suitability depends on the face, the history and the expectations, which is why a consultation with the prescriber comes first.6
Who may not benefit or may face additional risk
- People with neuromuscular junction disorders such as myasthenia gravis or Lambert-Eaton syndrome, or with amyotrophic lateral sclerosis (ALS).2
- People taking aminoglycoside antibiotics or other drugs that affect nerve-muscle signalling.2
- People taking blood thinners, who may bruise more; any change to these medicines needs the prescribing doctor’s input.1
- Anyone whose lines are mainly static, from sun damage or volume loss.
When a responsible clinician may advise against it
- Known allergy to any botulinum toxin product or its ingredients, or infection at the injection site.2
- Pregnancy or breastfeeding; it is generally not recommended and safety data are lacking.12
- Injections from another practitioner within the past few months that have not been disclosed.1
- Expectations that cannot be met, such as lifting sagging skin.
Alternatives
The right alternative depends on what is causing the line. Summary details below are from Mayo Clinic’s overview of wrinkle treatments.4
| Option | Best suited to | Key limitation |
|---|---|---|
| Daily sunscreen and stopping smoking | Slowing further damage | Prevents more than it reverses |
| Topical retinoids | Fine lines and blotchiness | Weeks to months to work; irritation; not for pregnancy |
| Dermal fillers | Folds and lines from volume loss | Repeat treatment needed; different risk profile |
| Chemical peels and laser resurfacing | Texture, sun damage, fine lines | Recovery time; risk of scarring and colour change |
| Face-lift or neck lift (surgical) | Sagging of the lower face and neck | Does not correct fine wrinkles; surgical risks |
For volume-related folds, see dermal fillers; for sagging, facelift surgery.
No treatment is a legitimate option
Expression lines are a normal part of a moving face and carry no health risk. Choosing to leave them alone, or to focus on sun protection, is a reasonable decision.
Procedure, preparation and anaesthesia
Because it is a prescription-only medicine, a healthcare professional such as a doctor or nurse prescriber must assess you before it is prescribed. The person who injects does not have to be the prescriber, but the prescriber is responsible for making sure they are trained.6
- Before: tell the clinician about any toxin injections in the past four months and any blood thinners.1
- Marking: you are usually asked to frown or raise your brows so the active muscles can be seen.
- Injection: a thin needle places small amounts into each target muscle; numbing cream, ice or vibration may be used.1
- Straight after: avoid rubbing or massaging the area for 24 hours and avoid lying down for two to four hours.1
No general or regional anaesthesia is involved, and the appointment itself is usually short.
Recovery and results timeline
Most people return to usual activities straight away, though it is sensible to check with the treating clinician.1 Small bumps fade quickly; bruises may take longer.
| Time | What typically happens |
|---|---|
| Day 0 | Possible redness, small bumps, pinpoint bleeding or bruising |
| Days 1–3 | Effect begins to appear12 |
| Week 1 onwards | Effect builds; full results can take a week or more1 |
| Months 3–4 | Movement gradually returns2 |
How long results last
For frown lines, the effect lasts about three to four months in the licensing trials.2 Repeat injections are usually spaced at least three months apart.1 Duration varies with the product, dose, muscle strength and area treated, so a stated duration is an average rather than a promise.
Pain and comfort
Most people feel little pain: a series of quick, sharp pricks with a very fine needle.1 Numbing cream, ice or vibration on the skin may be used to reduce discomfort.1
Afterwards, mild tenderness, swelling or a headache can occur.1 Persistent or worsening pain is not expected and should be reported.
Risks and complications
Expected temporary effects
Recognised complications
- Drooping upper eyelid (ptosis): the most common adverse reaction in the frown-line licensing trials, in 3% of treated people versus none on placebo.2 A systematic review of 35 studies (8,787 people) reported eyelid drooping in 2.5% and brow drooping in 3.1% after upper-face treatment, all resolving without treatment.10
- Asymmetry: crooked eyebrows or smile; lower-face asymmetries were reported in 6.9% in the same review.110
- Eye effects: dry or watery eyes, particularly after treatment near the eye.12
Rare serious complications
Spread of toxin effect. The US label carries a boxed warning that toxin effects can spread beyond the injection site, hours to weeks later, causing weakness, double vision, swallowing or breathing problems; deaths have been reported across licensed uses.2 The same label states there are no definitive serious reports of distant spread at the labelled cosmetic doses.2
Botulism from unlicensed or counterfeit products. Between 4 June and 6 August 2025, 41 confirmed cases of botulism linked to cosmetic injections were reported in England; 32 people were admitted to hospital and 8 needed intensive care. Most had received products not licensed in the UK.7 In 2024 the FDA warned of counterfeit Botox injected in several US states, with hospital admissions reported.8
Seek urgent medical help if, after an injection, you notice
- Difficulty swallowing, slurred speech or breathing difficulty.57
- Blurred or double vision, generalised weakness or difficulty holding up your head.8
- Signs of an allergic reaction or loss of bladder control.1
In the UK, use NHS 111 or emergency services.5 These symptoms can appear hours to weeks after treatment.1
How strong is the evidence?
| Claim | Vireon assessment | What supports it | Important limitation |
|---|---|---|---|
| BoNT-A reduces frown lines short term | Strong | Network meta-analysis of randomised controlled trials: all formulations far superior to placebo9 | Outcomes mostly at about one month, scored by investigators |
| One licensed product clearly outperforms the others | Limited | Indirect comparisons in the same meta-analysis9 | Few head-to-head trials; units differ between products |
| Short-term safety at cosmetic doses is acceptable | Moderate | Systematic review of 35 studies, 8,787 people10; licensing trial data2 | Mainly short-term, industry-linked trials; older review |
| Serious harm from distant spread at cosmetic doses | Uncertain incidence | Boxed warning and post-marketing reports2 | Rare events are poorly captured by trials |
| Unlicensed products carry a higher risk of botulism | Moderate | UK outbreak investigation and FDA counterfeit alert78 | Outbreak data, not controlled comparisons |
Most trials are short, focus on frown lines and are sponsored by manufacturers. Long-term data on decades of repeated treatment are limited, and rare complications are known mainly from case reports and regulatory surveillance rather than trials.
Products, regulation and treatment-specific red flags
Products licensed in the UK for aesthetic use include Alluzience, Azzalure, Bocouture, Botox, Letybo, Nuceiva and Relfydess.7 Selling or supplying unlicensed botulinum toxin is a criminal offence, and the MHRA has seized thousands of unlicensed vials since 2023.5 In 2025 the government confirmed plans for a licensing scheme for non-surgical cosmetic practitioners and premises in England, with details still being developed.12
Counterfeit vials can look convincing. In the FDA’s 2024 alert, warning signs included a generic “Botulinum Toxin Type A” label instead of the product’s own generic name, a dose size the manufacturer does not make and outer-carton text not in English on a product sold in the US.8
- No prescriber assessment, or a prescriber you never speak to.6
- Unusually low prices, treatment at home or at parties, or a practitioner who cannot show credentials.56
- Refusal to name the product or show the packaging and batch number.5
Cost drivers and what a quote should include
Costs vary with the number of areas treated, the product and dose, the prescriber’s and injector’s qualifications, and whether a review appointment is included. A quote should state:
- The product name and the areas to be treated.
- Who prescribes and who injects.6
- Whether a follow-up check and any top-up are included.
- What happens, and who pays, if a complication occurs.6
If you are travelling for treatment
- The prescriber’s assessment should happen in person before treatment.
- The full effect can take a week or more to show, so a review before you fly home may not be possible.
- Ask for the product name and batch number in writing to give to a clinician at home.
- Know who to contact at home if warning signs appear after you return.
Questions worth asking a clinician
- Are my lines mainly from movement, or from volume loss or sun damage?
- Which product will you use, and is it licensed in this country?
- Who is the prescriber, and what training does the injector have?
- How often do you see eyelid or brow drooping, and what do you do about it?
- Do any of my medicines or conditions change the risk?
Frequently asked questions
Does it hurt?
Most people feel only brief pricks.1 Numbing cream, ice or vibration can make it more comfortable.
When can I go back to work, exercise or drive?
Most people resume usual activities the same day.1 Avoid rubbing the area for 24 hours and lying down for two to four hours, and ask your clinician about strenuous exercise.
How soon will I see a difference?
Changes usually start within one to three days, and full results can take a week or more.1
How long does it last, and how many sessions will I need?
Each treatment typically lasts about three to four months, so maintaining the effect means repeat sessions.2
Can I fly after treatment?
We found no authoritative guidance setting a waiting period before flying. The practical issue is follow-up: plan how you would be assessed if warning signs or a droop appeared after you leave.
What if my eyelid droops?
Contact the treating clinician; in studies, eyelid and brow drooping resolved on their own as the toxin wore off.10 Seek urgent help instead if drooping comes with vision, swallowing or breathing problems.1
Bottom line
Botulinum toxin has good short-term evidence for softening movement-related lines, but it is a temporary, prescription-only medicine rather than a cosmetic product. The cause of your lines decides whether it is relevant. In practice, the biggest avoidable risk is not the licensed medicine itself but unlicensed products and unsupervised injectors.
Related reading
- Medical aesthetics overview
- Dermal fillers
- Facelift
- How to verify a doctor’s credentials
- Medical travel red flags
- Understanding a treatment quote
Sources
- Mayo Clinic Staff. Botox injections. Mayo Clinic; 2024. https://www.mayoclinic.org/tests-procedures/botox/about/pac-20384658. Accessed 5 November 2026.
- Allergan. BOTOX Cosmetic (onabotulinumtoxinA) for injection: full prescribing information. US Food and Drug Administration (Drugs@FDA); revised 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/103000s5306lbl.pdf. Accessed 5 November 2026.
- Mayo Clinic Staff. Wrinkles: symptoms and causes. Mayo Clinic; 2023. https://www.mayoclinic.org/diseases-conditions/wrinkles/symptoms-causes/syc-20354927. Accessed 5 November 2026.
- Mayo Clinic Staff. Wrinkles: diagnosis and treatment. Mayo Clinic; 2023. https://www.mayoclinic.org/diseases-conditions/wrinkles/diagnosis-treatment/drc-20354931. Accessed 5 November 2026.
- Medicines and Healthcare products Regulatory Agency. MHRA crackdown on illegal ‘Botox’ after victims left seriously ill. GOV.UK; 2025. https://www.gov.uk/government/news/mhra-crackdown-on-illegal-botox-after-victims-left-seriously-ill. Accessed 5 November 2026.
- NHS. Choosing who will do your cosmetic procedure. NHS website; 2023. https://www.nhs.uk/conditions/cosmetic-procedures/choosing-who-will-do-your-procedure/. Accessed 5 November 2026.
- UK Health Security Agency. HPR volume 19 issue 8: news (7, 14 and 28 August 2025) — iatrogenic botulism associated with cosmetic botulinum toxin injections. Health Protection Report, GOV.UK; 2025. https://www.gov.uk/government/publications/health-protection-report-volume-19-2025/hpr-volume-19-issue-8-news-7-august-2025. Accessed 5 November 2026.
- US Food and Drug Administration. Counterfeit version of Botox found in multiple states. FDA; 2024. https://www.fda.gov/drugs/drug-alerts-and-statements/counterfeit-version-botox-found-multiple-states. Accessed 5 November 2026.
- Li X, Sui C, Xia X, Chen X, et al. Efficacy and safety of botulinum toxin type A for treatment of glabellar lines: a network meta-analysis of randomized controlled trials. Aesthetic Plastic Surgery; 2023;47:365–377. https://doi.org/10.1007/s00266-022-03018-y
- Cavallini M, Cirillo P, Fundarò SP, et al. Safety of botulinum toxin A in aesthetic treatments: a systematic review of clinical studies. Dermatologic Surgery; 2014;40(5):525–536. https://pubmed.ncbi.nlm.nih.gov/24575858/ (DOI 10.1111/dsu.12463)
- Department of Health and Social Care. Botulinum toxin and cosmetic fillers for under 18s. GOV.UK; 2021. https://www.gov.uk/government/publications/botulinum-toxin-and-cosmetic-fillers-for-under-18s/botulinum-toxin-and-cosmetic-fillers-for-under-18s. Accessed 5 November 2026.
- Department of Health and Social Care. The licensing of non-surgical cosmetic procedures in England: consultation response. GOV.UK; 2025. https://www.gov.uk/government/consultations/licensing-of-non-surgical-cosmetic-procedures/outcome/the-licensing-of-non-surgical-cosmetic-procedures-in-england-consultation-response. Accessed 5 November 2026.
Article history
- — First published.