Botulinum toxin injections for frown lines (glabellar lines), commonly called Botox, place botulinum toxin type A into the lines between the eyebrows. Botox (the AbbVie product; the Korean label name is 보톡스주) is a prescription drug (a drug that needs a doctor’s prescription) approved by Korea’s Ministry of Food and Drug Safety (MFDS) for the temporary improvement of moderate to severe frown lines in adults aged 18 to 75. [as of September 2026]
Common questions
When does the effect start and how long does it last?
According to the Botox label (the official product information approved with the drug), the improvement in frown lines lasts about 3 to 4 months. The drug begins to act on the muscle 1 to 2 days after injection and grows stronger over the first week.
An analysis that pooled 4 clinical trials found that the middle value of how long the effect lasted was 120 days when frowning. That figure was calculated only for the 84.2% in whom an effect was confirmed on day 30.
Muscle size and use differ from person to person, so one person’s result can differ from these numbers. See the timeline
Is a drooping eyelid one of the side effects?
Yes. In the frown-line clinical trials on the label, 13 of the 405 people who received Botox (3%) had a drooping eyelid, and none of the 130 people who received a dummy injection did.
Facial pain, muscle weakness and facial paralysis each occurred in 1% of the people who received Botox.
How much the injection hurts and whether numbing cream is used do not appear in the label and studies reviewed for this article. See the side effects table
Does it smooth lines that are already deep?
People whose lines did not lessen even when the skin between the brows was spread by hand were excluded from the Botox Phase 3 clinical trials. The label advises caution in such cases.
The label explains frown lines as the result of muscle movement, and the approved use also covers lines related to the activity of the muscles between the eyebrows.
This article did not review studies that compared botulinum toxin with fillers. The difference between the two procedures is covered in How fillers and botulinum toxin differ (in Korean). See how it works
How often can it be injected?
According to the Botox label, injections should not be given less than 3 months apart. The safety and efficacy of more frequent injections have not been evaluated in clinical studies, and the label does not recommend it.
Injecting the forehead and the frown lines on the same day does not appear in the label and studies reviewed for this article. See the label
Once you start, do you have to keep going? Can the body build resistance?
The approved effect is a “temporary improvement” that lasts about 3 to 4 months. We could not confirm whether injections must continue after that, or whether repeated cosmetic use leads to resistance.
We found a study that pooled the rates at which antibodies form, but the study covered only patients treated for medical conditions such as dystonia, so its results could not be applied to frown lines. See what we have not confirmed
How much does it cost, and how many units are used?
We have not published prices yet. A range will appear here once we have at least 3 public prices for the same conditions on file.
The approved dose of Botox is 4 units at each of 5 points between the brows, 20 units in total. According to the label, the right dose is decided by watching the muscles move.
Each product measures its units on a different basis, so a figure such as “this much for 100 units” cannot be compared across products. When you look at a quote, check the product name together with the number of units. See why
Can I lie down or exercise on the day of treatment?
We did not find a basis in the label or in published studies for advice not to lie down or exercise. Advice differs from clinic to clinic, so check the actual instructions with the medical staff who treated you. See details
How do Korean-made and imported botulinum toxin products differ?
The difference we confirmed in the approval records is the country of manufacture. Of the 59 products with “보툴리눔” (botulinum) in the product name, 54 are made in Korea and 5 are imported.
Each product has its own label, and according to the Botox label, the units of one product cannot be converted into the units of another. This article did not review studies that directly compared their effects or side effects. See the approval record
What to ask at your consultation
The items below are based on the Botox label. If any of them apply to you, tell the medical staff before treatment. If a different product is used, adjust the questions to that product’s label.
- Which product will be used, and how many units? Knowing the product name and the number of units keeps you from comparing units across products by mistake.
- Across how many points will the dose be split? The approved dose of Botox is 20 units in total across 5 points.
- Have you had another botulinum toxin injection in the last few months? According to the label, receiving a different toxin before the effect of the previous one has worn off can excessively worsen neuromuscular weakness.
- Do you already have a drooping eyelid or clear asymmetry between the two sides of your face? People with these conditions were excluded from the Phase 3 clinical trials, and the label advises caution.
- Are you taking any drugs? According to the label, use with aminoglycoside antibiotics can increase the drug’s effect, so tell the medical staff about every drug you take.
- Are you pregnant or planning a pregnancy? According to the label, there are no adequate controlled studies in pregnant women. If you are breastfeeding, tell the medical staff that separately.
Contact the clinic right away if these symptoms appear after treatment
If swallowing or breathing becomes difficult after the injection, contact a medical facility or get emergency care right away. The label warns that the toxin can spread from the injection site to other parts of the body, and that difficulty breathing or swallowing can be life-threatening. See details
Evidence and details
What the Botox label says
Botox (보톡스주 on the Korean label) is the product name of a botulinum toxin type A product from AbbVie Korea. In everyday use, people call this procedure “Botox” regardless of the product. Each product used for the procedure has its own label, and anyone can read the labels in the MFDS drug database (Nedrug, 의약품안전나라). The table below shows the parts of the label for one product, Botox, that concern frown lines.
| Item | What the label says |
|---|---|
| Approved for | Adults aged 18 to 75 with moderate to severe frown lines |
| Approved wording | “Temporary improvement” of frown lines |
| Dose | 20 units in total, injected at 5 points (4 units per point) |
| Duration of effect | About 3 to 4 months |
| Injection interval | Not more often than every 3 months |
| Category | Prescription drug |
| Source | Botox label, item code 200804190, approved 2008-04-16 |
| Checked | 2026-09-14 |
The label does not say that lines disappear or that the effect lasts a long time. The safety and efficacy of more frequent injections have not been evaluated in clinical studies, and the label does not recommend it.
According to the label, the position, size and use of muscles differ from person to person. The right dose is therefore decided after observing, as a whole, how the patient moves the muscles to be injected.
The label also lists what to tell the medical staff. Receiving a different botulinum toxin before the effect of an earlier one has worn off can excessively worsen neuromuscular weakness, and use with aminoglycoside antibiotics can increase the drug’s effect. The label states that there are no adequate controlled studies in pregnant women.
On September 14, 2026, the MFDS drug database listed 59 items with “보툴리눔” (botulinum) in the product name. By the manufacture and import classification we checked the next day, 54 are made in Korea and 5 are imported. The imported items are 보톡스주 and 보톡스주 50단위 (Botox, Ireland and the US), 제오민주 and 제오민주50단위 (Xeomin, Germany), and 디스포트주 (Dysport, the UK). According to the Botox label, toxin content can differ between products, so the units of one product cannot be converted into the units of another.
How the effect on frown lines is explained
The label explains frown lines as the result of muscle movement. The corrugator supercilii and orbicularis oculi muscles move the center of the forehead and form lines between the brows, and the procerus and depressor supercilii muscles pull the forehead down. When Botox is injected, “chemical denervation” of those muscles begins 1 to 2 days later and grows stronger over the first week. Put simply, the injected muscles move less for a while.
The approved use also covers frown lines related to the activity of the corrugator supercilii or procerus muscle. People whose lines did not lessen when the skin between the brows was spread by hand were excluded from the Phase 3 clinical trials, and the label advises caution in such cases. People with drooping eyelids, clear facial asymmetry or deep skin scars are also listed for use with caution for the same reason.
When the effect starts and when it wears off
| When | What happens | Source |
|---|---|---|
| 1 to 2 days after injection | Begins to act on the muscle | Botox label |
| Week 1 | The effect grows stronger | Botox label |
| About 3 to 4 months | How long the effect lasts | Botox label |
| About 120 days | Middle value of how long the effect lasted (among people with a confirmed effect on day 30) | An analysis that pooled 4 clinical trials |
One analysis, published in 2012, combined data from 4 Phase 3 clinical trials and looked at 621 people who received 20 units. On day 30 after injection, an effect was confirmed in 84.2%. Among these people only, the middle value (median) of how long the effect lasted was reported as 120 days when frowning and 131 days at rest. The 15.8% without a confirmed effect on day 30 were not included in this calculation.
What the clinical trials reported
One clinical trial, published in 2002, was run jointly at several centers, and neither the patients nor the researchers knew who received the real drug. A total of 264 people with moderate or worse frown lines received 20 units or a dummy injection (placebo), and the researchers followed them for 120 days.
According to the researchers, the lines of people who received Botox faded more than those of people who received the dummy injection at every visit, and many people kept the effect through day 120. The researchers reported drooping eyelids in 5.4%, and most cases were mild.
Allergan, Inc., the maker of the product used in the study, paid for the trial. Of the research team, 5 were Allergan employees and 2 were paid consultants to Allergan.
Another analysis, published in 2015, pooled the results of 7 placebo-controlled clinical trials that used 20 units, covering 1,474 people. The research team reported that the rate of people who saw an effect was about 34 times that of the placebo group (19 to 60 times when the margin of error is taken into account). The team also reported that the overall frequency of adverse events did not clearly differ from the placebo group. In the clinical trials on the label, however, drooping eyelids occurred in 13 people (3%) in the Botox group and 0 people in the placebo group.
What side effects have been reported
The Botox label lists the adverse reactions that occurred in 1% or more of the Botox group in the frown-line clinical trials, alongside the figures for the placebo group (the people who received a dummy injection).
| Adverse reaction | Botox group (405 people) | Placebo group (130 people) |
|---|---|---|
| Drooping eyelid | 13 people (3%) | 0 people |
| Facial pain | 6 people (1%) | 0 people |
| Muscle weakness | 6 people (1%) | 0 people |
| Facial paralysis | 5 people (1%) | 0 people |
In a post-marketing survey conducted in Korea and included in the label, 5 of 423 frown-line patients (1.2%) had adverse events over 4 years, and no serious adverse events were reported.
Post-marketing reports also include lagophthalmos (토끼눈증) after use for frown lines, and the Mephisto sign (메피스토 징후) after use around the forehead muscle (frontalis) in patients with frown lines or chronic migraine. The label does not explain what the two terms mean.
The first thing the label warns about is spread of the toxin
The first item in the warnings of the Botox label, “distant spread of toxin effect,” says that the toxin can spread from the injection site to other parts of the body and cause botulism. Difficulty breathing or swallowing can be life-threatening, and there are case reports of death from spread of the toxin. A rapid loss of muscle strength is another symptom that can appear. The label names children treated for spastic cerebral palsy as a group at particular risk, and states that symptoms have also occurred at doses lower than those used to treat cervical dystonia.
The label does not separately report how often toxin spread occurred at the 20-unit frown-line dose. If swallowing or breathing becomes difficult after the injection, contact a medical facility or get emergency care right away.
What to be careful about on the day of treatment
Advice not to lie down on the day of treatment, or to avoid exercise and alcohol for a certain time, differs from clinic to clinic. We did not find a basis for this advice in the label or in published studies. Check the actual instructions with the medical staff who treated you. The evidence behind each rule is covered in Precautions after filler and botulinum toxin (in Korean).
We have not published prices yet
We publish a price range only after we have collected at least 3 publicly posted prices for the same conditions. For frown-line injections we have none so far.
The Botox label warns that toxin content can differ between products, so “the units of one product cannot be converted into the units of another product.” When you compare prices, check the product name together with the number of units, not “how much for 100 units.”
What we have not confirmed yet
- We have not collected a single price yet.
- We did not find a basis in the label or in published studies for advice about lying down, rubbing the area, exercise or alcohol on the day of treatment.
- We could not confirm whether injections must continue once started, or whether repeated cosmetic use leads to resistance. A study that pooled the rates at which antibodies form covered only patients treated for medical conditions such as dystonia, so its results could not be applied to frown lines.
- We did not review studies that compared botulinum toxin with fillers for frown lines that are already deep.
- How much the injection hurts, whether numbing cream is used, and injecting the forehead and the frown lines on the same day do not appear in the label and studies reviewed for this article.
- Of the 59 products, Botox is the only one whose label we read. Other products may differ in indications (the approved uses and conditions), dose, warnings and adverse reactions.
- We did not look for studies that directly compared the effects or side effects of Korean-made and imported products.
- We could not confirm who paid for the two analyses that pooled clinical trials (2012 and 2015).
- The label does not explain what lagophthalmos and the Mephisto sign mean, and we have not confirmed their meaning yet.
- The numbers from the clinical trials and the label are values pooled from many people. According to the label, muscle size and use differ from person to person, so one person’s result can differ from these numbers.
Related pages
- How fillers and botulinum toxin differ (in Korean)
- Chin botulinum toxin for a pebble chin (a bumpy-looking chin caused by the chin muscle) (in Korean)
- Precautions after filler and botulinum toxin (in Korean)
- Guide to types of skin procedures (in Korean)
Sources
- Korea’s Ministry of Food and Drug Safety (식품의약품안전처), MFDS drug database (의약품안전나라). 보톡스주 [Botox] (클로스트리디움 보툴리눔 독소 A형 [Clostridium botulinum toxin type A]), 한국애브비(주) [AbbVie Korea], item code 200804190, approved 2008-04-16. Indications, dosage and administration, and from the precautions for use, the sections on warnings, use with caution, adverse reactions, interactions and pregnant women. Korean originals of the quoted label text: “일시적 개선” [temporary improvement], “화학적 탈신경” [chemical denervation], “독소 효과의 원거리 확산” [distant spread of toxin effect], “한 제품의 단위(unit)는 다른 제품의 단위로 변환될 수 없다” [the units of one product cannot be converted into the units of another product]. 의약품안전나라 (Nedrug) · checked 2026-09-14
- Korea’s Ministry of Food and Drug Safety (식품의약품안전처), MFDS drug database (의약품안전나라). Search for “보툴리눔” [botulinum] in product names: 59 results (54 made in Korea, 5 imported). Checked 2026-09-14, manufacture and import classification checked 2026-09-15
- 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):840-9. PMID 12063480 · abstract only · funding and author affiliations checked in the journal’s publication information · funded by Allergan, Inc. · authors include Allergan employees and paid consultants · the 2002 trial of 264 people in the text
- Glogau R, Kane M, Beddingfield F, et al. OnabotulinumtoxinA: a meta-analysis of duration of effect in the treatment of glabellar lines. Dermatol Surg. 2012;38(11):1794-803. PMID 23106853 · abstract only · funding not confirmed · the analysis that pooled 4 clinical trials in the text
- Guo Y, Lu Y, Liu T, et al. Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Glabellar Lines: A Meta-Analysis of Randomized, Placebo-Controlled, Double-Blind Trials. Plast Reconstr Surg. 2015;136(3):310e-318e. PMID 26313835 · abstract only · funding not confirmed · the analysis that pooled 7 clinical trials in the text
Written by SKINMODU 2026-09-14 · Reviewed 2026-09-14 (Codex · Gemini) · Wording revised 2026-09-14 · Summary questions added 2026-09-15 · Wording re-reviewed 2026-09-18 (Codex · Gemini · Fable) · No prices collected yet · Rebuilt in the new layout 2026-09-27 · English edition 2026-10-04, translated from the Korean page as of 2026-09-27