Anti-wrinkle injections last three to four months for most people. Movement starts to return gradually from about week ten, and lines are usually back to how they were by month four to six if you do not repeat the treatment. The first treatment often wears off a little sooner; after several treatments many people find the effect stretches to four or five months.
Why does it wear off?
The medicine, botulinum toxin type A, blocks the signal between a nerve and a muscle. The block is not permanent: over roughly three months the nerve grows new endings and the muscle starts receiving its instructions again. This happens in everyone and is the reason the treatment is repeated rather than done once.
Wearing off is gradual, not sudden. A typical pattern is:
- Weeks 2 to 8: full effect. The treated muscle is at its weakest and lines are at their softest.
- Weeks 8 to 12: slight movement returns, usually noticed first in the forehead. Lines are still much softer than before.
- Weeks 12 to 16: movement is clearly back. Most people book their next treatment in this window.
- Months 4 to 6: the muscle is back to normal strength. Lines that were etched in before treatment reappear; lines that were only present on movement may stay a little softer for a while, because the skin has had months of rest.
What makes it wear off faster?
Dose. The single biggest factor. A low dose weakens the muscle less and for less time. Some budget clinics use low doses to keep prices down, and some practitioners deliberately start low on a first visit to avoid over-treating. Either way, a result that fades by week six to eight is usually a dose issue, and the fix is a review and an adjusted dose next time.
Muscle size and strength. Men, people with strong frown habits and people treating the masseter (jaw) muscle have more muscle to relax and often need more units for the same duration. A standard dose in a large muscle wears off sooner.
First treatment. The effect from a first treatment is often shorter, perhaps ten to twelve weeks, than from later ones. Nobody is certain why, but the usual explanation is that the muscle has not yet been weakened over time and the frowning habit is still strong.
Metabolism and exercise. People who exercise hard and often tend to report shorter results. The evidence is mostly from practitioner experience rather than trials, but it is consistent enough that many clinics mention it.
Which area was treated. The forehead is treated conservatively, because over-treating it causes a heavy brow, so it wears off first. Crow’s feet and frown lines generally last longer.
The product. Several brands are licensed in the UK. They are broadly similar in duration when used at equivalent doses, though practitioners sometimes have a preference for a particular area. Your practitioner should tell you which product was used; it is on your consent form.
What makes it last longer?
Repeated treatment. With regular treatment, the muscle gets weaker over time and the habit of using it fades. Many people on their fourth or fifth treatment find the gap stretches to four or five months, and some can drop to two or three treatments a year.
The right dose for you. A practitioner who reviews you at two weeks and adjusts the dose on the next visit will get you a longer, more consistent result than one who treats everyone the same.
Avoiding the early mistakes. In the first day or two the medicine is still settling into the muscle. Rubbing the area, lying face down, saunas and hard exercise can, in theory, move it or reduce how much binds. Our aftercare guide covers this. The effect on duration is small, but it costs nothing to follow.
Does it stop working over time?
Rarely. A small number of people develop antibodies to the medicine so that it stops having an effect. The risk is higher with large doses given frequently, which is one reason clinics leave at least three months between treatments. If a treatment that used to work suddenly does nothing, tell your practitioner; switching to a different brand sometimes helps.
Far more common than true resistance is a change in what is being treated. As you get older, lines that were caused by movement become etched into the skin, and lines caused by volume loss or sun damage appear alongside them. These do not respond to anti-wrinkle injections, so the treatment can seem to be “working less” when it is doing the same job on a different face.
How often should I have it?
Every three to four months is typical, and clinics will usually not treat you sooner than twelve weeks after your last session. Some people prefer to wait until movement has fully returned, then treat; others prefer to top up at twelve weeks so the lines never fully come back. Both are reasonable. Treating before the previous dose has worn off does not make the result stronger, it just uses more medicine.
For a longer gap, ask your practitioner about dose rather than about frequency. A slightly higher dose in a well-chosen muscle generally lasts longer than more frequent low doses.
What this means for the cost
At three treatments a year and a typical UK price of £175 for one area, the yearly cost is around £525; at three areas it is nearer £900. If regular treatment lets you stretch to two or three sessions a year, the cost falls accordingly. The cost guide has prices by city.
When to go back
Book your next appointment when movement has clearly returned and the lines bother you again, usually at twelve to sixteen weeks. Go back sooner, at any time, if you notice drooping, unevenness or anything that worries you; these effects are temporary but a practitioner can sometimes correct them, and should want to know. Use the clinic listings on this site to find a registered practitioner near you and compare their published prices.
Sources
- NHS: Botulinum toxin injections
- Electronic Medicines Compendium: summaries of product characteristics for UK-licensed botulinum toxin type A products (duration of effect and dosing intervals), medicines.org.uk