Wrinkle Relaxing › The Science
Explore the Science

Wrinkle Relaxing, in depth.

Relaxing the muscles that fold the skin, to soften expression lines and help prevent them deepening — treated conservatively, for a natural result. Here is the science, the evidence, and an honest account of what to expect.

The mechanism

Softening the movement

Wrinkle-relaxing treatment works on the muscles beneath the skin. By gently relaxing the muscles that fold the skin, it softens the lines they create — and helps stop them deepening.

Many expression lines — across the forehead, between the brows, at the corners of the eyes — are created by the repeated contraction of the muscles beneath. A muscle-relaxing treatment works by temporarily reducing a targeted muscle's ability to contract, at the point where nerve meets muscle. With the movement softened, the overlying skin creases less, and existing lines are given the chance to settle. The effect is temporary, and wears off gradually over months as normal movement returns.

Done well, the aim is never a frozen or expressionless look — it is softened, natural movement, with lines eased rather than erased. Matt treats conservatively, for a result that looks like you, rested.

Onset

A few days

The effect begins to appear within a few days, building to its full result at around two weeks — the point at which any fine adjustment is judged.

Duration

Around 3–4 months

For facial expression lines, the effect of a single treatment typically lasts around three to four months, after which movement gradually returns.

Approach

Natural, not frozen

Treated conservatively and mapped to your face — softening movement while keeping expression, never freezing it.

The science & evidence
  • Muscle-relaxing treatment works by blocking the chemical signal (acetylcholine) that tells a muscle to contract, temporarily and reversibly.
  • A pooled analysis of clinical trials for frown lines found the median duration of effect was around 120–131 days — roughly four months — in those who responded.
  • The treatment is one of the most studied in aesthetic medicine, with a long-established and well-understood safety profile.
Glogau R et al., Dermatol Surg 2012;38:1794–1803. Mechanism: neuromuscular junction / SNAP-25 literature.
Important — how we can talk about this treatment

Muscle-relaxing injectables are a prescription-only medicine in the UK. That means the law does not allow them to be advertised to the public, or their brand names promoted. This page is therefore educational — explaining the science and the approach — rather than promotional. Every treatment follows a personal consultation with Matt, and is prescribed only where appropriate. We do not list products, doses or prices here.

The areas

Where it helps

The same underlying science addresses expression lines, an enlarged or overactive jaw muscle, and excessive sweating.

Expression Lines

Strong evidence

Forehead lines, frown lines and crow\'s feet

The classic areas: horizontal forehead lines, the vertical frown lines between the brows, and the fine lines at the outer corners of the eyes. Relaxing the muscles behind them softens these lines and helps prevent them etching in.

Evidence — strong, trial-proven
  • Frown-line treatment is supported by large randomised controlled trials, with a median duration of effect of roughly four months in responders.
  • Forehead and crow\'s-feet treatment is well established, with duration typically in the same three-to-four-month range.
Glogau R et al., Dermatol Surg 2012; RCT evidence base.
What to expect
  • Onset: A few days, full effect at about two weeks.
  • Duration: Around three to four months.
  • Downtime: Minimal — occasional small bruise or short-lived redness.

Jaw & Clenching

Good evidence

Softening an enlarged or overactive jaw muscle

Relaxing the masseter — the main chewing muscle — can ease clenching and grinding, relieve associated jaw tension, and, with repeated treatment, soften and slim the line of a strong or enlarged lower face.

Evidence — what the research shows
  • A systematic review of randomised trials found muscle-relaxing treatment significantly reduced clenching force compared with both placebo and a dental splint.
  • Studies show reduced muscle bulk, bite force and jaw pain; slimming builds with repeated treatment.
Chen KJ, Tsai TH et al., Aesthetic Plast Surg 2023;47:775–790.
What to expect
  • Onset: Relief of clenching over the first weeks; slimming builds over months.
  • Duration: Around three to four months for symptom relief; longer, progressive slimming with repeat treatment.
  • Course: Often several initial sessions for full slimming.

Excessive Sweating

Strong evidence

Underarm hyperhidrosis

The same treatment, placed into the underarm, calms the nerve signals that drive the sweat glands — markedly reducing excessive underarm sweating for many months at a time.

Evidence — strong, trial-proven
  • A 52-week randomised controlled trial found a marked reduction in underarm sweating, with a median duration of effect of around 197–205 days (roughly six to seven months).
  • The treatment is well tolerated and outperforms several alternatives for excessive sweating.
Lowe NJ et al., J Am Acad Dermatol 2007;56:604–611.
What to expect
  • Onset: A noticeable reduction over the first week or two.
  • Duration: Often around six to nine months, sometimes longer with repeat treatment.
  • Downtime: Minimal.
Advanced areas

The finer details

Beyond the classic areas, the same science addresses a number of finer, more advanced concerns — each treated with restraint. These are more subtle, technique-sensitive treatments, always mapped to your face.

The advanced options

  • Gummy smile — softening the upward pull of the top lip on smiling, so less gum shows.
  • Bunny lines — easing the fine wrinkles that appear across the top of the nose on animation.
  • Chin dimpling — smoothing a dimpled or ‘orange-peel’ chin caused by an overactive chin muscle.
  • Brow lift — a subtle, non-surgical lift of the brow by relaxing the muscles that pull it down.
  • Perioral lines — softening the fine vertical lines around the mouth, and a gentle relaxing of the top lip. This adds no volume — a different approach to lip filler.

Because these areas are subtle and highly individual, they are always assessed and mapped to your face at consultation. Matt will advise whether they suit you, and treats each conservatively for a natural result.

Safety & suitability

Well established, expertly placed

Muscle-relaxing treatment has one of the longest and best-understood safety records in aesthetic medicine. Most effects are mild, temporary and closely related to the skill of the injector. A few honest points guide the conversation at consultation.

Good to know

Normal, temporary effects

What to expect.

  • A small bruise, short-lived redness or a mild headache in the first days
  • Full effect takes about two weeks — it isn\'t instant
  • Rarely, temporary heaviness or slight asymmetry as it settles — careful, expert placement minimises this
Discuss first

Worth telling us about

These guide safe, appropriate treatment.

  • Any neuromuscular condition
  • Current medications
  • What you\'d like to achieve — so treatment is mapped to keep your natural expression
Not suitable

When we won\'t proceed

For your safety, treatment isn\'t possible in these situations.

  • Pregnancy or breastfeeding
  • Certain neuromuscular disorders
  • Active skin infection in the treatment area
  • Under 18 — cosmetic treatment is not provided to minors

This is educational information to help you prepare — it isn\'t a diagnosis, and it isn\'t exhaustive. Treatment is prescription-only, follows a personal consultation with Matt, and is provided only where appropriate.

Begin with a consultation

Every treatment begins with a personal consultation with Matt, so it's mapped to your face and your goals — and prescribed only where appropriate.

Book a ConsultationBack to Wrinkle Relaxing
Instagram Call WhatsApp Book