How Long Do Anti-Wrinkle Injections Last?
Medical Director Dr Sin Yong explains how long anti-wrinkle injections last on the forehead, frown lines, crow's feet and jaw, why the effect wears off, and how often treatment is usually repeated.
WhatsApp to Enquire →Key facts ↓Anti-wrinkle injections usually last about three to four months on the forehead, frown lines and crow's feet, with movement returning gradually rather than all at once. Jaw slimming lasts longer: the muscle thins over weeks and the slimmer contour often persists for several months. Dose, muscle strength, the area treated and the product all change how long it lasts. See anti-wrinkle injections in Singapore.
- Frown lines: in a placebo-controlled trial of 264 people, frown lines stayed significantly softer than with placebo at every visit, and the effect was maintained for many through day 120; mild eyelid droop occurred in 5.4 in 100 [1].
- Across studies: a review of 42 studies of one botulinum toxin type A formulation found onset most often within 2 to 3 days and duration most often reported as four months, with some studies showing effect at five or six months [2].
- Jaw: in 383 people followed after masseter injections, muscle thickness fell by 31 in 100 on average at three months, with thinning noticed after two to four weeks [4].
- Bite force: in 20 people given masseter injections, bite force was reduced at three months and no longer significantly reduced at six months [5].
- Repeated jaw treatment: after three masseter treatments six months apart, muscle volume was 12 in 100 smaller one year after the last injection, in a small study of six women [6].
How long do anti-wrinkle injections last, area by area?
For lines caused by movement on the upper face, the usual answer is about three to four months. The first softening appears within a few days, the full effect at about one to two weeks, and movement then returns gradually. In a placebo-controlled trial of 264 people treated for frown lines, the effect was maintained for many through day 120 [1]. A review of 42 studies of one botulinum toxin type A formulation found duration was most often reported as four months, with a minority of studies showing effect at five or six months [2]. Studies define "lasting" differently, so these are ranges, not promises.
| Area | When it shows | How long it usually lasts | Notes |
|---|---|---|---|
| Frown lines (between the brows) | 2 to 4 days; full at 1 to 2 weeks | About 3 to 4 months [1][2] | Strong muscles may need a higher dose |
| Forehead lines | 2 to 4 days; full at 1 to 2 weeks | About 3 to 4 months | Doses kept low to protect brow position, which can shorten the effect |
| Crow's feet | 2 to 4 days; full at 1 to 2 weeks | About 3 to 4 months | Placement keeps a natural smile |
| Jaw slimming (masseter) | Thinning over 2 to 6 weeks [4] | Bite force recovers by about 6 months; visible slimming may last longer [5] | Repeated treatment can keep the muscle smaller [6] |
| Micro-dose (very small, spread doses) | Within days | May be shorter than standard doses | Chosen to soften rather than still movement |
Why do anti-wrinkle injections wear off?
Botulinum toxin blocks the release of acetylcholine, the chemical signal a nerve uses to tell a muscle to contract. The nerve and muscle are not damaged. Over the following weeks the nerve endings grow small new sprouts that restore some signalling, and later the original nerve terminal recovers and the sprouts are removed. Laboratory work in mouse muscle traced this two-step repair, with transmission through the sprouts by about 28 days and a later return to the original terminals [3].
This is why the effect fades gradually rather than switching off on a set date, and why a muscle that has been relaxed for a while does not suddenly overreact when the effect ends. It also explains why there is no cream, supplement or exercise that reliably makes the result last much longer: duration is set mainly by how much of the muscle's nerve supply was blocked, and how quickly that nerve repairs.
What makes anti-wrinkle injections last longer or shorter?
Dose relative to the muscle is the main factor. A strong frown muscle given a small dose will regain movement sooner than one given a dose matched to its strength. Men often have bulkier muscles and may need more. The area matters: the forehead is deliberately under-treated because the frontalis is the only muscle that lifts the brows, and overtreating it can drop the brows and make the eyes look heavy. Very small, spread-out doses keep more expression and tend to wear off sooner. Formulations differ in how they spread and how quickly they act, and the choice is made per area.
Explanations such as a fast metabolism or frequent exercise are often given online, but good evidence that they shorten the effect is limited. A rarer cause of a shorter or weaker response is the body making neutralising antibodies to the toxin. A meta-analysis of 43 studies and 8,833 patients, mostly treated with higher medical doses for conditions such as dystonia and spasticity, found neutralising antibodies in 1.8 in 100 overall, and more often with longer treatment [7]. Cosmetic doses are much smaller, but this is one reason frequent small top-ups are avoided.
How long do anti-wrinkle injections last on the jaw and forehead?
On the jaw, the aim is to thin the masseter, the chewing muscle that can make the lower face look square. The change is slow to appear and slow to reverse. In 383 people followed after masseter injections, the muscle was 31 in 100 thinner on average at three months, with thinning first noticed after two to four weeks [4]. In 20 people, bite force was reduced at three months and no longer significantly reduced at six, although the authors note that visible slimming may last longer [5]. When treatment is repeated, the muscle can stay smaller: after three treatments six months apart, masseter volume was 12 in 100 below baseline a year after the last injection, in a small study of six women [6]. More detail is in masseter slimming injections.
On the forehead, the effect typically lasts about three to four months, and it may feel shorter than in the frown area because doses there are kept conservative to preserve brow position and natural expression. Treating the frown area and forehead together keeps the brow balanced as both wear off; see micro-dose anti-wrinkle injections for the lighter approach.
How often should you have anti-wrinkle injections, and what does wearing off look like?
Many people repeat treatment two or three times a year, once movement has clearly returned. The labelled minimum interval for at least one product is 12 weeks [2], and topping up sooner than that is avoided. Wearing off is gradual: you notice that you can frown or lift your brows a little more, then fine lines reappear with expression, and later at rest. Lines usually return to where they were, not worse, although ageing carries on in the meantime.
Some people prefer to repeat as soon as movement starts to return; others wait until lines bother them. Either is reasonable. What helps most is a consistent dose and placement that are reviewed and adjusted, rather than chasing the effect with extra units. If an expected result fades unusually fast, the dose, placement and product are reviewed before anything is added.
How are anti-wrinkle injections planned at IN Eternity Clinic?
Anti-wrinkle injections are a prescription medicine in Singapore, given by a doctor with a product registered with the Health Sciences Authority. At IN Eternity Clinic, Dr Sin Yong assesses how each muscle moves at rest and in expression, maps the injection points, and chooses the dose and formulation for each zone, aiming to soften lines while keeping natural movement. A review at about two weeks checks the result and the balance between areas, and the dose for next time is adjusted from what is seen.
The same medicine is used, in different doses and sites, for jaw slimming, neck bands and underarm sweating. Cost depends on the number of areas and the dose each muscle needs, and is explained at consultation. How long other treatments last is compared in how long aesthetic treatments last. Results vary, and suitability is decided at an in-person assessment.
What Dr Sin Yong looks for
- How strongly each muscle moves, at rest and in full expression.
- Brow position and any heaviness of the upper eyelids before treatment.
- Lines at rest versus lines only with movement, which may need a different treatment.
- How long previous treatments lasted, with which dose and areas.
- Pregnancy, breastfeeding and neuromuscular conditions, which mean avoiding treatment.
General clinical observations used at consultation; they describe what is checked, not any individual result.
Frequently asked questions
How long does "Botox" last?
"Botox" is one brand name of botulinum toxin, a prescription medicine; IN Eternity Clinic uses the general term anti-wrinkle injections, and the product is chosen for each area. For lines on the forehead, frown area and crow's feet, the effect usually lasts about three to four months, varying between people.
How long do anti-wrinkle injections last on the jaw?
For jaw slimming, the masseter thins over two to six weeks. In studies, bite force returned by about six months, while the slimmer contour may last longer. Repeated treatment can keep the muscle smaller; in one imaging study, injections were given every six months.
How long do anti-wrinkle injections last on the forehead?
Usually about three to four months. Because forehead doses are kept conservative to protect brow position and expression, some people notice movement returning a little sooner there than between the brows. The forehead and frown area are usually planned together so the brow stays balanced as both wear off.
How often should I have anti-wrinkle injections?
Many people repeat treatment two or three times a year, once movement has returned. Top-ups sooner than about 12 weeks are avoided. The interval is guided by how your muscles respond and how long previous treatments lasted, and the dose is adjusted from what is seen at review.
What does it feel like when anti-wrinkle injections wear off?
It is gradual. You find you can frown or raise your brows a little more, then fine lines appear again with expression and later at rest. Lines return to their previous state rather than becoming worse because of the treatment.
Do anti-wrinkle injections last longer with repeated treatment?
For the jaw, repeated treatment can keep the masseter smaller, as shown in a small imaging study. For lines, some people find the interval lengthens over time, but this varies and has not been shown consistently in studies, so each treatment is planned on review.
Why did my anti-wrinkle injection wear off so fast?
The usual reasons are a dose that was small for the strength of the muscle, a conservative dose in the forehead, or placement that missed part of the muscle. Rarely, antibodies reduce the response. The dose and placement are reviewed before more is added.
Book an assessment
IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, Singapore 228210. By appointment with Medical Director Dr Sin Yong. Monday to Saturday, 11am to 8pm. WhatsApp or call +65 8815 3008. At IN Eternity Clinic a consultation fee applies, and it is waived if you go ahead with any medical treatment; the fee is S$120.
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References
- Carruthers JA, Lowe NJ, Menter MA, et al. A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines. J Am Acad Dermatol 2002;46(6):840-849. doi:10.1067/mjd.2002.121356
- Nestor M, Cohen JL, Landau M, et al. Onset and duration of abobotulinumtoxinA for aesthetic use in the upper face: a systematic literature review. J Clin Aesthet Dermatol 2020;13(12):E56-E83. PMID 33488922
- de Paiva A, Meunier FA, Molgo J, Aoki KR, Dolly JO. Functional repair of motor endplates after botulinum neurotoxin type A poisoning: biphasic switch of synaptic activity between nerve sprouts and their parent terminals. Proc Natl Acad Sci U S A 1999;96(6):3200-3205. doi:10.1073/pnas.96.6.3200
- Kim NH, Chung JH, Park RH, Park JB. The use of botulinum toxin type A in aesthetic mandibular contouring. Plast Reconstr Surg 2005;115(3):919-930. doi:10.1097/01.prs.0000153236.79775.a0
- Agren M, Nanchaipruek Y, Phumariyapong P, et al. Duration of bite force reduction following a single injection of botulinum toxin in the masseter muscle bilaterally: a one-year non-randomized trial. J Oral Rehabil 2023;50(5):343-350. doi:10.1111/joor.13434
- Chang CS, Lin S, Wallace CG, et al. Masseter muscle volume changes evaluated by 3-dimensional computed tomography after repeated botulinum toxin A injections in patients with square facial morphology. Ann Plast Surg 2019;82(1S Suppl 1):S29-S32. doi:10.1097/sap.0000000000001705
- Rahman E, Alhitmi HK, Mosahebi A. Immunogenicity to botulinum toxin type A: a systematic review with meta-analysis across therapeutic indications. Aesthet Surg J 2022;42(1):106-120. doi:10.1093/asj/sjab058
These sources describe mechanisms and general evidence. They are not a promise of any individual result; suitability is decided at an in-person assessment.