Anti-wrinkle injection gone wrong: signs, causes and what can help

What can go wrong after anti-wrinkle injections?

Most wrinkle-relaxing injections go smoothly, and the problems that do occur are usually temporary because the medicine wears off. The common side effects are minor: bruising, a mild headache, tenderness and small bumps at injection points that settle within 15 to 30 minutes. Less often, the result is not what was planned.

The unwanted effects people ask about most:

• A droopy eyelid: the upper lid sits lower, usually on one side.
• A heavy or low brow: the forehead feels heavy and the brows sit lower.
• Uneven brows: one brow higher than the other, or a sharply raised outer brow.
• Smile and mouth changes: a flatter or uneven smile, or difficulty with straws and whistling.
• Too little effect: lines that still move after two weeks.

Rarely, the medicine affects muscles further away, causing double vision or difficulty swallowing; difficulty swallowing or breathing needs urgent help.

Wrinkle-relaxing injections work by temporarily reducing the signal from nerve to muscle, so the treated muscle moves less. Problems usually come from the medicine reaching a muscle it was not meant to, a dose that is too strong or too weak for that muscle, or placement that does not suit the person's brow and lid position.

Movement gradually returns over about three to four months, sometimes nearer six, so even an unwanted effect has a time limit. There is no product that switches the medicine off, so correction relies on time, balancing doses and supportive care. For how the treatment is done at SkinRev Lab, see the main wrinkle-relaxing injections page.

How common are anti-wrinkle injection complications?

Unwanted effects after wrinkle-relaxing injections are uncommon in experienced hands, and almost all are temporary. Brow drop and asymmetry are the effects reviewers name most often.

• A 2020 narrative review identified a lowered brow and asymmetry as common adverse effects, and stressed that treating doctors should know how to recognise and manage them (Kassir and colleagues, 2020).
• A 2026 narrative review reported a droopy upper eyelid in about 1% to 14% of people after frown-line injections, falling below 1% in series from experienced injectors. It usually appeared within about 7 to 10 days, and most cases settled within two to four weeks, although some lasted longer. Uneven brows were described as relatively common but rarely measured, and changes around the mouth as rare (Freixo and Camões-Barbosa, 2026).
• A 2016 article on managing a droopy lid or brow described an overall rate of 5.4% in one multicentre trial, with many cases attributed to inexperienced injectors, and suggested that experienced injectors likely see under 1%. It noted that a droopy lid often settles within three to four weeks and a lowered brow within about six weeks (King, 2016).

Two points follow. First, the person injecting, their assessment of your brow and lid position, and the dose and placement they choose all make a large difference. Second, because effects wear off, the main questions after a problem are how to manage it while it lasts and how to plan the next treatment differently. Your doctor will advise how this applies to you.

Droopy eyelid after anti-wrinkle injections

A droopy eyelid after wrinkle-relaxing injections is temporary, usually appears within about three to ten days, and often settles within two to four weeks. It happens when the medicine reaches the small muscle that lifts the upper lid, most often after injections for frown lines placed close to the brow.

How to recognise it:

• The edge of the upper lid sits lower and covers more of the coloured part of the eye.
• It usually affects one side, and may be worse when tired or at the end of the day.
• It differs from a heavy brow, where the brow itself sits lower and the upper lid skin feels crowded.

What usually helps:

• Time: the lid lifts as the medicine's effect fades from that muscle.
• Prescription eye drops: a doctor may advise drops that stimulate a separate small lifting muscle and can lift the lid slightly while the effect wears off. They are not suitable for everyone, for example people at risk of a certain type of glaucoma, so a doctor must assess first.
• Avoiding further injections near the area until it has settled.

If the lid is low enough to affect vision or driving, tell the doctor, who can advise on practical measures. Eye pain, a red eye or double vision are different and need prompt review.

Risk is lowered by assessing brow and lid position before treatment, dosing conservatively near the brows and placing injections accurately. For other causes of a low lid, see droopy eyelids.

Heavy brow and a heavy forehead

A heavy brow or forehead after wrinkle-relaxing injections happens when the forehead muscle that lifts the brows is relaxed too much, and it is temporary, often easing over about six weeks as movement returns. The forehead muscle is the only muscle that raises the brows, so when it is weakened too far, the brows sit lower and the upper face can feel heavy.

Who is more prone:

• People with heavy upper lids or low-set brows, who rely on the forehead muscle to keep the brows up.
• People who have had previous eyelid surgery or have certain eye conditions.
• Older skin, where the brows have already descended.
• Treatment of the forehead without the frown muscles, or injections placed too low on the forehead.

What usually helps:

• Time: the brow position improves as forehead movement returns.
• Small balancing doses into the muscles that pull the brows down may lift the brow slightly, where the doctor judges this appropriate.
• No further forehead treatment until the next plan has been reviewed, with lighter dosing next time.

There is no quick reversal for a heavy brow, so prevention matters. A doctor should look at brow height, lid heaviness and forehead movement before treating the forehead, and in some people the forehead is treated lightly or not at all. For people whose main concern is brow position, see non-surgical brow lift, and for line treatments by area, see frown lines and forehead lines.

Uneven brows and an uneven result

Uneven brows or an uneven result after wrinkle-relaxing injections are relatively common, are usually judged at the two-week review, and may be balanced with a small additional dose. Many faces are naturally asymmetric, and muscles on each side can respond differently, so some unevenness is not a sign that something went badly wrong.

The common patterns:

• A sharply raised outer brow: sometimes called a quizzical look, when the outer part of the forehead muscle stays active while the centre is relaxed.
• One brow higher than the other: from uneven dosing, placement or muscle strength.
• Uneven lines: one side of the forehead or one set of crow's feet still moving more.

What usually helps:

• Waiting until about two weeks: the effect builds over that time, so early unevenness often evens out.
• A small corrective dose into the muscle that is still overactive, such as above the raised outer brow.
• Reassurance and observation for mild unevenness, which fades as the effect wears off.

Photos taken before treatment help here, because they show which asymmetries were already present. For the next treatment, the doctor can adjust the dose on each side. A review at about two weeks is part of the plan at SkinRev Lab, and it is the right time to raise any unevenness.

Smile, lip and mouth changes

Changes to the smile or mouth after wrinkle-relaxing injections are uncommon, happen when the medicine affects the muscles that lift the cheek or move the lips, and fade as the effect wears off. They can feel more unsettling than brow changes because the mouth is used constantly for speaking and eating.

How they can arise:

• Crow's feet treatment placed too low can weaken muscles that lift the cheek, giving a flatter or uneven smile.
• Lip flip or gummy smile treatment can make it harder to use a straw, whistle, or hold liquid in the mouth if the dose is too strong.
• Jaw slimming treatment near the corners of the mouth can occasionally affect smile muscles, giving an uneven smile.

What usually helps:

• Explanation, reassurance and time while the effect wears off.
• Practical measures, such as using a straw or taking small sips, while lip control is weaker.
• In selected cases, a small balancing dose on the other side, where the doctor judges this appropriate.

Doses around the mouth are kept low for this reason, and a doctor should explain what to expect before treating these areas. For more on the treatments involved, see crow's feet treatment, lip flip vs lip filler and jaw slimming injections.

Bruising, headache and when it seems not to work

Bruising, a mild headache and tenderness are the common side effects of wrinkle-relaxing injections and usually settle within days; lines that still move after two weeks are reviewed rather than assumed to be a failure. Neither is usually a sign of a complication.

Bruising and headache:

• Pinpoint bruises can appear at injection points and can be covered with make-up.
• A mild headache on the day or the next day is common and short-lived.
• For the rest of the day, avoid rubbing or massaging the treated areas, lying flat for a few hours, saunas and strenuous exercise.

When it seems not to work:

• Softening starts within a few days, but the full effect takes about two weeks, so judging earlier can mislead.
• Strong muscles, or a dose kept deliberately light near the brows, may leave more movement than expected.
• True resistance to the medicine is very rare.
• Lines etched into the skin at rest may soften but not fully disappear, because the injections relax muscle rather than fill or resurface skin.

At the two-week review, a doctor can decide whether a small top-up suits you or whether another approach would help more. For deep lines at rest, treatments that fill or remodel the skin may suit better; see wrinkle relaxers vs fillers.

Warning signs: what is normal and when to get help

Small bumps for up to half an hour, pinpoint bruising and a mild headache are normal after wrinkle-relaxing injections; difficulty swallowing, speaking or breathing, double vision or spreading weakness are not, and need urgent help. Use the table as a general guide, and contact your provider or a doctor if you are unsure.

If you were treated elsewhere and cannot reach your provider, any doctor can assess urgent symptoms.

How Dr Sin Yong assesses and corrects anti-wrinkle injection problems

At SkinRev Lab, Dr Sin Yong, medical adviser, assesses problems after wrinkle-relaxing injections by examining your face at rest and in motion, checking brow and lid position, and reviewing what was injected and when. Because there is no way to switch the medicine off, correction means managing the effect while it lasts and planning the next treatment differently.

What helps the assessment:

• The date of injection and the areas treated.
• The product, dose and injection points, if you have a record.
• Photos of your face before treatment and since the change began.
• Any history of eyelid surgery, eye conditions or neuromuscular conditions, and your current medicines.

What correction may involve, where appropriate:

• Observation and reassurance where the change is mild and expected to fade.
• Prescription eye drops for a droopy eyelid, if suitable for you.
• Small balancing doses for uneven brows or a raised outer brow.
• Practical advice for smile or lip changes while they last.
• Referral to an eye specialist for double vision or eye symptoms.
• A revised plan for the next treatment, with adjusted doses and placement.

Some effects simply need time, and correction cannot shorten every one. Dr Sin Yong will explain what is realistic, and correction is priced at consultation. If your treatment was done elsewhere, it is still worth contacting that provider too, as they hold your treatment records. At SkinRev Lab, the product used is named and recorded at each visit.

How to lower the risk: questions to ask before anti-wrinkle injections

The most useful way to lower the risk is to have wrinkle-relaxing injections from a doctor who assesses your brow and lid position first, explains the dose and placement, and includes a review at about two weeks. These questions help:

• Who will inject, and are they a doctor trained and experienced in facial anatomy?
• Will my brow and lid position be assessed first, especially if my upper lids are heavy or my brows sit low?
• Which product will be used, and will the product, dose and points be recorded?
• Is a review at about two weeks included, and how are uneven results handled?
• What should I expect in the first two weeks, and who do I contact if something changes?

Tell the doctor about: pregnancy or breastfeeding, neuromuscular conditions such as myasthenia gravis, infection at injection sites, a known allergy to the product, previous eyelid surgery, eye conditions, and medicines that may interact, such as certain antibiotics.

Your part after treatment: avoid rubbing or massaging the treated areas, avoid lying flat for a few hours, and skip saunas and strenuous exercise for the rest of the day. For an event, treat at least two to three weeks ahead so the review fits in.

A doctor who suggests a lighter dose, or a different treatment, is often protecting your result. Wrinkle-relaxing injections do not fill deep folds or lift sagging skin, and other treatments may suit those concerns better.