Key takeaways
- They treat dynamic lines, the ones made by muscle movement, mainly on the upper face.
- They do not treat volume loss, sagging or sun damage. Those need other approaches.
- The effect begins in a few days, peaks around ten days to two weeks and fades over months.
- The dose and placement are the skill. Small, precise doses keep expression natural.
- It is a medical treatment: a doctor should assess you, choose the dose and be available afterwards.
How do anti-wrinkle injections work?
Every time you frown, a nerve tells a small muscle between your eyebrows to contract. Over years, that repeated folding etches a line into the skin.
Botulinum toxin blocks the release of a chemical messenger called acetylcholine at the point where the nerve meets the muscle. The muscle gets the signal more weakly, so it relaxes. The skin above it stops folding as deeply, and the line softens.
See, what happens is, the effect is temporary because the nerve gradually grows new connections to the muscle. DermNet describes the nerve-muscle connection being re-established after around three months. That is why the treatment wears off, and why it is very controllable: if you do not like it, it does not stay.
Which lines does it treat?
| Area | What causes the line | How well it usually suits |
|---|---|---|
| Frown lines (between the eyebrows) | Muscles that pull the brows together and down | One of the main uses |
| Forehead lines | The muscle that raises the eyebrows | Common use; needs careful dosing to avoid a heavy brow |
| Crow's feet | The muscle that closes the eye when you smile | Common use |
| Lines at rest that are deeply etched | Years of folding plus skin changes | Softens them; may need skin treatments too |
| Hollows, folds from volume loss, sagging | Fat and bone changes, laxity | Not suitable; these need support or tightening instead |
It is also used outside the upper face and for medical problems such as excessive sweating. Those uses need more experience and a separate, careful discussion. If you want to understand the difference between movement lines and volume lines, my article on how skin ages explains the layers.
What happens in a session?
Normally it goes like this:
- Assessment. I watch your face move: frowning, raising your eyebrows, smiling. I look at your brow position, the strength of each muscle and any unevenness. I ask about your medical history and medicines.
- Plan. We agree which areas, the product and the dose, written down with the price, before anything is done.
- Injection. A very fine needle places small amounts into specific points. DermNet describes a 30-gauge needle with small injections, and local anaesthetic is usually not needed. It takes a few minutes.
- After. You can usually go back to work. Mild redness or small bumps settle within a short time.
When will I see the effect?
According to the US prescribing information for one licensed product, the muscle effect typically begins one to two days after injection and increases over the first week. DermNet describes weakness within two to four days and the maximum effect around ten days. I review people at about two weeks, because that is when you can judge the result fairly and adjust if needed.
How do I keep it looking natural?
Basically, the dose is the skill. A general dose suits most faces, but adjusting for your muscle strength, brow position and how much movement you want to keep is what decides whether you look rested or frozen.
- Start lower. It is easy to add a little at review. It is not possible to remove it.
- Keep some movement. Most of my patients want to look like themselves when they talk and laugh.
- Treat the cause, not every line. A line from volume loss will not improve with more toxin, and chasing it is how faces start looking strange.
- Space it out. DermNet advises that injections should generally not be given more often than every 8 to 12 weeks, because frequent dosing raises the risk of antibodies that reduce the effect.
Who should not have it?
According to DermNet, avoid or postpone treatment if you: - Are pregnant or breastfeeding - Have a condition that causes muscle weakness, such as myasthenia gravis or motor neurone disease - Have an infection over the area to be treated - Have had an allergic reaction to botulinum toxin before - Are taking certain antibiotics (aminoglycosides) that can increase its effect
Blood thinners such as aspirin increase the chance of bruising, so tell your doctor, but do not stop any prescribed medicine on your own. For side effects in more detail, see anti-wrinkle injection safety.
A note on products and doses
Different licensed products contain botulinum toxin, and their units are not interchangeable. The US prescribing information is explicit that units of one product cannot be compared or converted to another. So when you compare prices, compare the product and the dose written down, not just "one area". At our clinic, the product and dose are written down before treatment.
How we approach this at Dr Tvacha
At our centres in Thane, Andheri, Bandra and Dahisar, anti-wrinkle injections sit inside the Long Game Anti-ageing Plan. We start with a Rs 499 face assessment, decide whether movement lines are really the main issue, and write the product, dose and price down before treatment. I review at two weeks. If I think you do not need it yet, I will say so. Read about the Long Game Anti-ageing Plan, or how long the effect lasts.
Frequently asked questions
Do anti-wrinkle injections hurt?
Most people describe a brief sting or pinch at each point. The needle is very fine and the doses are tiny, so local anaesthetic is usually not needed. The whole injection part takes a few minutes. Some people feel a mild headache for a few hours after forehead treatment, which settles on its own or with paracetamol.
Will I look frozen?
Not if the dose is matched to your face. A frozen look usually comes from high doses across the whole forehead. I prefer to start lower, keep some natural movement and adjust at the two-week review. The goal is that people see you as rested, not that they can tell something was done.
Can I go to work straight after?
Usually yes. There may be small bumps or slight redness at the injection points for a short while, and occasionally a small bruise. Most people return to normal activities the same day. I give simple aftercare instructions on the day, and you can message us if anything worries you.
Is botulinum toxin the same as a filler?
No. Botulinum toxin is a medicine that relaxes muscles, so it softens lines caused by movement. Hyaluronic acid fillers are gels that add support or volume where it has been lost. They solve different problems, and many faces need neither, one, or a small amount of each at different times.
How often will I need it?
The effect usually lasts about three to four months, so people who continue tend to repeat it a few times a year. Some people find the interval lengthens with repeated treatment. It is always optional. If you stop, the muscles simply return to how they were, and the lines gradually come back.
Written by
Dr Amit KarkhanisAesthetic Physician · MBBS, Dip. Dermatology (UK) · Reg. No. 2001/02/1124Founder of Dr Tvacha, practising in Thane since 2005. Leads the weight loss and hair programmes.
Sources
- Botulinum toxin (DermNet)
- US FDA prescribing information: onabotulinumtoxinA (2018)
- The Science and Theory behind Facial Aging (Plastic and Reconstructive Surgery Global Open, 2013)
- Application of Nonsurgical Modalities in Improving Facial Aging (International Journal of Dentistry, 2022)
This article is for general education and does not replace a consultation. Medicines and treatments are prescribed only after a doctor's assessment. Last reviewed 25 October 2026.