Anti-Wrinkle Injections (Botulinum Toxin): How They Work, What They Treat, Side Effects and the Things Clinics Leave Out

What botulinum toxin can soften, what it cannot, how long it lasts, and why dose and placement matter more than the product.

Anti-wrinkle injections use botulinum toxin, a purified protein often known by the brand name Botox, to temporarily relax specific facial muscles. When the muscle moves less, the lines it creates in the skin above it soften. Treatment takes about 15 to 30 minutes, with no downtime. The effect begins after three to five days, peaks at around ten days to two weeks, and typically lasts three to four months, sometimes longer.

It is the most common aesthetic treatment in the world, and it is often treated as casually as a beauty appointment. It is a prescription medicine injected into the face, and the difference between a result that looks rested and one that looks frozen, heavy or uneven comes down to the assessment, the dose and exactly where it is placed. This guide explains how it works, what it can realistically do, and how to recognise safe practice.

What it is — and what it cannot do

Botulinum toxin blocks the release of the chemical messenger that tells a muscle to contract. Injected in tiny, precise amounts into a chosen muscle, it reduces that muscle's movement for several months. Lines caused by that movement, called dynamic lines, soften because the skin is no longer folded repeatedly. Gradually the nerve endings recover, movement returns and the effect wears off.

It treats lines caused by movement. It works best on the forehead, the frown lines between the brows, and the crow's feet at the sides of the eyes.

It does not fill. Lines that are present at rest and deeply etched into the skin (static lines) may soften but will not disappear, and they may need skin treatments or filler. Hollows from volume loss need volume, such as facial fat transfer.

It does not lift sagging skin. It can raise the tail of the brow by a few millimetres. A brow or eyelid that has genuinely descended needs a brow lift or eyelid surgery. A long upper lip needs a lip lift.

It is temporary. It needs repeating to maintain the effect.

The most important thing on this page: dose and placement, not the product

Most of the problems people associate with botulinum toxin are problems of assessment, dose and placement, not of the medicine itself.

The frozen look comes from too high a dose across too wide an area, so the face loses expression.

Heavy, lowered brows come from treating the forehead without accounting for the fact that the forehead muscle is what holds the brows up. In people whose brows sit low, or who already raise their forehead to keep their eyes clear, a strong forehead dose can make the eyes look hooded and tired.

A drooping upper eyelid (ptosis) comes from toxin spreading to the muscle that opens the eye. It is uncommon, usually lasts a few weeks, and is related to where and how the injections are placed.

Unnatural brow shapes, such as an over-arched "Spock" brow, come from uneven treatment across the forehead.

A good treatment starts by watching how your face moves: frowning, raising the brows, smiling and squinting. The dose is then planned muscle by muscle. Many practitioners prefer to start conservatively and review at two weeks, adding a little if needed, rather than doing too much at once.

The product must also be genuine. Only use licensed products, supplied through proper pharmaceutical channels and injected from a sealed vial. It is reasonable to ask which product will be used and to see the packaging. Counterfeit and unlicensed products carry serious risks.

What it can treat

Forehead lines. The horizontal lines from raising the eyebrows.

Frown lines (glabellar lines). The vertical lines between the eyebrows.

Crow's feet. The lines at the outer corners of the eyes.

Bunny lines. The small lines on the sides of the nose when scrunching.

A small brow lift. Relaxing the muscles that pull the tail of the brow down.

Lip flip. A small amount above the upper lip to turn it slightly outwards. The effect is subtle and short-lived.

Gummy smile. Reducing how much the upper lip lifts when smiling.

Chin dimpling ("orange-peel" chin).

Downturned corners of the mouth.

Neck bands. Visible vertical bands in the neck.

Jaw muscle (masseter). For a wide, square jaw or teeth grinding (bruxism), relaxing the jaw muscle can slim the lower face over several weeks and reduce grinding.

Excessive sweating (hyperhidrosis). Of the underarms, palms or forehead.

Lower-face and neck treatments need particular care, because the muscles there control speech, smiling, chewing and swallowing.

Products

Several licensed botulinum toxin products exist, including onabotulinumtoxinA (Botox), abobotulinumtoxinA (Dysport), incobotulinumtoxinA (Xeomin) and others. They are all effective. Their doses are measured in units that are not interchangeable between products, so the number of units only means something for the specific product used.

In Türkiye, only a limited number of botulinum toxin products are officially authorized for medical use. Dr. Feryal Yıldız works with two carefully selected, established botulinum toxin brands, choosing between them according to each patient’s individual anatomy, muscle activity, treatment goals and previous response.

For Dr. Yıldız, Botox is never a one-product, one-dose-fits-all treatment. Product selection, dosage and injection technique are individually tailored to achieve a refined result while preserving natural facial expression.

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Who performs your treatment

Treatment is assessed and performed by Op. Dr. Feryal Yıldız, a specialist in plastic, reconstructive and aesthetic surgery. She qualified from Ege University Faculty of Medicine in 2013 and completed her specialist training in plastic, reconstructive and aesthetic surgery at Istanbul University–Cerrahpaşa in 2018.

Dr. Feryal Yıldız is a European Board-Certified Plastic Surgeon, a member of ISAPS (International Society of Aesthetic Plastic Surgery) and TPRECD (Turkish Society of Plastic, Reconstructive and Aesthetic Surgeons), with an educational background at some of Türkiye’s leading universities.

Her approach to Botox and facial aesthetics is shaped not only by years of clinical experience, but also by a deeply personal understanding of the treatment. Having received Botox herself for many years, Dr. Yıldız has observed its effects, longevity and subtle changes over time firsthand, alongside treating a wide range of patients.

This experience has reinforced one of her core principles: there is no universal Botox technique. Every face has different anatomy, muscle dynamics, expressions and aesthetic priorities.

For Dr. Yıldız, the goal is never a “Botox look.” It is to understand how much, where and — just as importantly — where not to inject, while preserving natural expression and individuality.

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Who this suits

Anti-wrinkle injections suit adults over 18 who are in good health and bothered by lines caused by facial movement, or by one of the other conditions above.

It is not suitable during pregnancy or breastfeeding. It is also not suitable for people with neuromuscular disorders such as myasthenia gravis, with an infection or active skin condition at the treatment site, or with a known allergy to any component of the product.

Tell your practitioner about any bleeding disorder, blood-thinning medicine or supplement, certain antibiotics, previous treatments and their results, and any upcoming surgery or events.

The treatment

A numbing cream may be applied first. The face is cleaned, and the medicine, diluted with sterile saline, is injected with a very fine needle at planned points. Most people describe a brief pinch. The appointment takes about 15 to 30 minutes, and you can return to your normal day immediately.

The effect begins after three to five days and reaches its peak at around ten days to two weeks. A review at around two weeks allows small adjustments.

After treatment

• Keep your head upright for the first four hours. Avoid lying down and bending forwards.
• Do not rub, massage or press on the treated areas for the rest of the day.
• Avoid strenuous exercise, saunas, steam rooms and hamams for the first day or two.
• Avoid alcohol on the day of treatment, as it can increase bruising.
• Avoid make-up on the treated areas for the rest of the day.
• Avoid facials, facial massage and strong sun for the first few days.
• Wash your face gently, with cool water.

How long it lasts

Most people find the effect lasts three to four months. Some find it lasts longer, and a first treatment may wear off sooner. Movement returns gradually, not suddenly. With regular treatment, some people find their lines are softer between sessions and they need treatment less often, because the muscle has been less active. The effect is not permanent, though, and stopping treatment is safe: the face returns gradually to how it would have been.

Side effects and risks

Serious complications are rare when licensed products are used correctly. The recognised side effects include:

Bruising, redness and small bumps at the injection points. These usually settle within hours to days.

Headache. It is usually mild and short-lived.

A frozen or heavy appearance, from too high a dose or a wide spread.

Lowered or heavy brows, particularly after forehead treatment.

Drooping of the upper eyelid. It is uncommon, temporary, and usually settles within a few weeks.

Asymmetry, usually correctable at review.

Smile or speech changes after lower-face treatment, or chewing weakness after high doses to the jaw muscle.

Difficulty swallowing or neck weakness after large neck doses. It is rare.

Allergic reaction. It is rare.

Reduced effect over time. It is rare, but some people develop antibodies that make treatment less effective.

Spread beyond the treatment area. It is very rare at cosmetic doses, but seek medical help immediately if you notice difficulty swallowing, speaking or breathing, or generalised muscle weakness.

If you are travelling to Istanbul

Most international patients have anti-wrinkle injections as part of a trip for another treatment, not as a trip on their own. If you do:

Timing. The effect takes up to two weeks to develop. If you want a review and possible adjustment, plan to have the treatment early in your stay, or arrange a review at home.

Before surgery. If you are also having facial surgery, discuss the timing. Sometimes injections are planned before or after surgery rather than on the same day.

Records. Ask for a written record of the product, the dose and the areas treated, so that whoever treats you next can build on it.

Choosing a practitioner

Choose a doctor. Botulinum toxin is a prescription medicine, and in expert hands complications are rare and manageable. Ask who will inject you and what their qualification is.

Ask which product will be used, and see the sealed packaging.

Expect an assessment of how your face moves before any injection, and a plan explained muscle by muscle.

Ask about a review at two weeks.

Be wary of very low prices, "packages" of many areas treated at once without assessment, and treatment in non-medical settings.

Frequently asked questions

Is botulinum toxin the same as Botox?
Botox is one brand of botulinum toxin. Other licensed brands work in a similar way, but their doses are measured differently.

How long does it last?
Typically three to four months, sometimes longer. A first treatment may wear off sooner.

How soon will I see results?
The effect begins after three to five days and peaks at around ten days to two weeks.

Does it hurt?
Most people describe a brief pinch. A numbing cream can be used.

Will I look frozen?
You should not. A well-planned treatment softens lines while keeping natural expression. A frozen look usually means too high a dose or too wide an area.

Can it lift my brows?
It can raise the tail of the brow by a few millimetres. A brow that has genuinely descended needs a brow lift.

Is it safe?
Serious complications are rare when licensed products are injected correctly by a trained doctor. Temporary side effects such as bruising, headache or, less often, a drooping eyelid can occur.

Can I have it if I am pregnant or breastfeeding?
No. Treatment is not recommended during pregnancy or breastfeeding.

Does it prevent wrinkles?
Relaxing a muscle regularly reduces how often the skin folds, which can slow the deepening of lines. It does not prevent ageing.

What happens if I stop?
Movement returns gradually, and your face returns to how it would have been. Stopping does not make lines worse.

Can it slim the jaw?
Yes. Relaxing an enlarged jaw muscle can slim a square lower face over several weeks, and it can also reduce teeth grinding.

Arranging a consultation

If you are considering anti-wrinkle injections, the useful next step is an assessment of how your face moves and which lines are dynamic, static or caused by volume loss. That should come with an honest answer to whether injections, another treatment or a combination will help.

You are welcome to contact the clinic to arrange a consultation with Op. Dr. Feryal Yıldız. There is no obligation to proceed, and you should not be asked to decide on the day.

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