Botox for frown lines lasts about three to four months, according to the FDA label. In two clinical trials, crow’s feet results lasted a median of about four months or longer. Movement returns gradually rather than all at once, and your dose, muscle strength, and treatment area all change the timeline.
Written by Kiara DeWitt, BSN, RN, CPN
Medically reviewed by Dr. Josh Allen, D.O., Medical Director
Medical disclaimer: This article provides general education and does not replace medical advice. Botox is a prescription treatment. A licensed provider must determine candidacy, treatment areas, units, and maintenance timing. Individual results vary.
The BOTOX Cosmetic prescribing information puts the effect on frown lines between the brows at about three to four months. Results are temporary. After that, the treated muscle gradually regains its normal movement.
Botox doesn’t stop working on a single day. The change usually happens in stages:
Because movement often returns before lines reach their old depth, a little motion doesn’t mean the treatment is gone. Botox also takes time to reach its full effect, so measure duration from your peak result rather than your appointment date. Here’s more on how long Botox takes to work.
| Treatment area | How long it lasts | Source |
|---|---|---|
| Frown lines (between the brows) | About 3 to 4 months | BOTOX Cosmetic label |
| Crow’s feet (around the eyes) | Median of about 4 months or longer in trials | Two phase 3 trials, 24 units |
| Forehead lines | Similar; your injector will advise for your dose | Label pairs forehead treatment with frown lines |
| Masseter (jaw) | Off-label; timing varies, and your injector will plan it | No label duration |
Frown lines. The three-to-four-month figure comes straight from the label, based on the approved 20-unit dose.
Around the eyes. A report on two phase 3 trials followed people treated with 24 units for crow’s feet. Among those who responded, median response lasted 125 to 148 days in one trial and 119 to 121 days in the other, depending on whether investigators or patients rated it.
Forehead. The label treats forehead lines together with frown lines rather than on their own, so forehead results generally track the same timeline. Your injector can tell you what to expect for your dose and anatomy.
Masseter. Masseter treatment is off-label and timing varies; your injector will plan it.
Losing most of the effect after one month is earlier than the label’s three-to-four-month window. It doesn’t always mean the treatment failed. Common reasons include:
A conservative first dose. An injector may start with fewer units to avoid heaviness or an unwanted brow change, then adjust at the next visit. A lighter dose can look natural but fade sooner.
Strong muscles. Larger or more active muscles can regain movement sooner, especially with a light dose. The answer isn’t always more units; your injector has to balance duration against brow position and natural expression.
Partial movement, not full wear-off. Small movements can return while lines still look softer at rest. Compare your face with photos from before treatment, not from your peak result.
First-time treatment. The American Society of Plastic Surgeons notes that some people find their first treatment doesn’t last as long as later ones. This doesn’t happen to everyone.
Placement. Botox only affects the muscles where it’s placed. If a connected muscle stays active, the treated area can seem to move again quickly.
Different products. Units differ between brands, so a unit count from another product can’t be compared directly with Botox. Here’s what a unit of Botox is.
Call your injector if:
Seek urgent medical care for trouble swallowing, speaking, or breathing, widespread muscle weakness, or vision problems after any botulinum toxin treatment.
Nurse injectors assess what faded first.
Botox $7.77 per unit with membership ($24.99/month), or $12 per unit without it.
In frown lines, the research says it can. A 48-week study compared single doses of 40, 60, and 80 units with the label dose of 20 units in women with moderate to severe frown lines. Median response lasted 19.7 weeks with 20 units and at least 24 weeks with each higher dose, with no apparent effect on safety measures.
A few things to keep in mind:
Your injector will weigh duration against your anatomy, the look you want, and safety.
Rarely, yes. Secondary nonresponse means Botox worked at first, then stopped working at a later treatment. A 2022 international consensus review links it to neutralizing antibodies that can form after repeated injections. Published rates in aesthetics are low, but the panel believes the true rate is likely underestimated. It expects rates to rise as aesthetic doses approach those used in medical treatment.
A 2025 narrative review adds that younger patients may build up larger lifetime doses, and that preventing nonresponse matters because there’s no solid data on how to treat it.
A result that fades early once is far more likely to come from dose, placement, or muscle strength than from resistance. If you notice a weaker response across several treatments, tell your injector.
The BOTOX Cosmetic label notes that the safety of treating more often than every three months has not been evaluated. For most people, that makes the label’s three-to-four-month window a sensible guide, adjusted to when your movement actually returns.
If your result fades early, ask for a review rather than an automatic top-up. Your injector can look at what came back first and adjust units, placement, or timing at your next scheduled visit.
Keeping simple records makes that review more useful:
For more on scheduling, see our guide to how often to get Botox.
The label treats forehead lines together with frown lines, which last about three to four months. Forehead results generally follow a similar timeline, and your injector can tell you what to expect for your dose.
In two phase 3 trials using 24 units for crow’s feet, median response lasted about four months or longer.
Common reasons include a conservative first dose, strong muscles, placement, or partial movement returning before the full effect is gone. Contact your injector for a review.
Talk with your injector first. The label notes that treating more often than every three months has not been evaluated, so a review may make more sense than more Botox.
Yes. A lower dose may not control a strong muscle for as long. Your injector should reassess movement and placement before adding units.
In one study of frown lines, 40 to 80 units lasted longer than the 20-unit label dose. Doses above 20 units are off-label, cost more, and aren’t right for everyone.
The American Society of Plastic Surgeons notes that some people find later treatments last longer than their first. It doesn’t happen to everyone.
Masseter treatment is off-label and timing varies; your injector will plan it.
Botox is temporary. The label puts frown-line results at about three to four months, and crow’s feet trials showed a median of about four months or longer. If yours fades sooner, dose, muscle strength, and placement are the first things to review.
With Botox at InjectCo, your nurse injector can look at what returned first and plan your next visit around how your face actually responds.
Get timing that fits your results.
Botox $7.77 per unit with membership ($24.99/month), or $12 per unit without it.
Medical Disclaimer: The information in this article is for educational purposes only and does not constitute medical advice. Results vary by individual. Always consult a licensed healthcare provider before beginning any medical treatment or aesthetic procedure.
Dr. Allen earned his Doctor of Osteopathic Medicine at Lake Erie College of Osteopathic Medicine and completed his emergency medicine residency with Texas A&M. As Medical Director, he reviews InjectCo’s treatments, protocols, and patient education content for accuracy and safety across all nine Texas locations.
