How far does 20 units of Botox go?

Botox is one of the most popular non-surgical cosmetic procedures for reducing the appearance of wrinkles and fine lines on the face. It works by temporarily relaxing the muscles that cause wrinkles to form over time. Many people considering Botox are curious about how far a certain number of units will go in treating different areas of the face. This article provides an in-depth look at how far 20 units of Botox typically spreads when used on common treatment areas.

What is Botox?

Botox is the brand name for botulinum toxin type A, a protein produced by the bacterium Clostridium botulinum. When injected into muscles, Botox blocks nerve signals, causing temporary muscle relaxation and weakness. This reduces skin wrinkling that develops with facial expressions and repetitive movements over time.

The effects of Botox take 2-14 days to appear and last 3-6 months. After this, as the Botox wears off, wrinkles and fine lines will gradually reappear, and retreatment is needed to maintain results.

Botox injections are customized to the individual and their treatment goals. Factors like the size of the muscle, thickness of the skin, and depth of wrinkles all impact how much Botox is needed to achieve optimal results in a particular area.

How Botox Units are Measured

Botox is measured in units. One unit of Botox is the smallest detectable dose. The number of units needed depends on several factors:

– Treatment area – Some areas need more Botox to relax the larger or stronger muscles. The forehead and crow’s feet require more units than the nose or chin area.

– Severity of wrinkles – More units are required to smooth deeper wrinkles versus fine lines.

– Gender – Women’s facial muscles tend to be smaller and weaker than men’s. Therefore, women generally require fewer units to achieve similar results as men.

– Muscle mass – The size and thickness of the muscle also impact the amount of Botox required. Larger or thicker muscles need more units relax fully.

– Expertise of injector – Experienced injectors use the minimum effective dose needed to achieve optimal results with minimal risk of side effects.

How Many Units are in a Botox Vial?

Botox comes in a sterile vacuum-dried powder form inside a glass vial. Each vial of Botox contains either 50 units or 100 units of botulinum toxin type A.

Once reconstituted with sterile saline, each vial of 50 units makes up 0.5 ml of liquid Botox. This means:

– 1 ml of reconstituted Botox contains 100 units
– 0.1 ml of reconstituted Botox contains 10 units
– 0.05 ml of reconstituted Botox contains 5 units

Knowing the concentration of units per ml allows the injector to precisely measure out and deliver the desired dose.

How Far Does 20 Units of Botox Go?

Now that we understand Botox units, we can take a closer look at how far 20 units typically spread:


The forehead is often one of the first facial areas to show signs of aging. Frowning, raising the eyebrows, and making surprised expressions can etch lines horizontally across the forehead over time.

Most people need 10-30 units total to smooth forehead wrinkles. Therefore, 20 units of Botox can treat a moderate forehead area nicely. It relaxes the corrugator muscles between the brows as well as the frontalis muscle which lifts the eyebrows.

Crow’s Feet

Crow’s feet are the fine radial wrinkles that form at the outer corners of the eyes during smiling or squinting. About 6-15 units are needed per side to relax the orbicularis oculi muscles that contract here.

20 units of Botox could treat mild to moderate crow’s feet on both eyes. Alternatively, the full 20 units could treat more pronounced crow’s feet on just one eye area.

Frown Lines

Vertical frown lines between the eyebrows often make people appear angry, sad, or upset even when they aren’t. These are also called the “elevens” based on their 11-shaped appearance.

Approximately 10-25 units of Botox can smooth frown lines. 20 units would provide a moderate treatment, relaxing the muscles enough to soften the lines but still allowing some natural expression.

Bunny Lines

Bunny lines are the small wrinkles that develop on the sides of the nose from frequent scrunching. This area is more delicate and requires less Botox – about 5-15 units per side.

20 units would allow a more complete relaxation of the tiny nasal muscles versus just a subtle softening of bunny lines. Full treatment may cause a slight smile or nostril flare if overdone.

Smoker’s Lines

Also called lip lines, smoker’s lines form vertically above the upper lip from pursing the lips around cigarettes or drinking straws. About 2-6 units per line smooths these area nicely.

20 units of Botox could almost fully treat smoker’s lines on both sides of the upper lip for a complete reduction. Or a more conservative approach may use less than 20 units to soften the lines while allowing some natural puckering motions.

Neck Bands

The platysmal neck bands that run vertically down the neck are also treatable with Botox. Approximately 20-60 units are needed depending on the length and severity of the bands.

20 units of Botox for neck bands would provide a conservative starting treatment. While likely not providing dramatic smoothing, it may soften the bands’ appearance before slowly increasing the dose at subsequent treatments.

Downturned Mouth Corners

Frowning and chewing can turn down the corners of the mouth over time. 5-15 units per side lifts the corners upward for a pleasant, relaxed appearance.

20 units split between the two sides could lift mouth corners into a subtle smile shape. Balance is important to avoid asymmetry. Less may be recommended at first.

Treatment Area Typical Botox Range What 20 Units May Treat
Forehead 10-30 units Moderate forehead wrinkles
Crow’s Feet 6-15 units per side Mild to moderate crow’s feet on both eyes or more significant on one eye
Frown Lines 10-25 units Moderate frown lines between eyebrows
Bunny Lines 5-15 units per side Fuller treatment of bunny lines on nose
Smoker’s Lines 2-6 units per line Almost complete treatment of lines on both sides of upper lip
Neck Bands 20-60 units Conservative initial treatment
Downturned Mouth 5-15 units per side Subtle lift to both mouth corners

Factors That Impact How Far Botox Spreads

While these general unit guidelines provide a good starting point, several factors impact precisely how far 20 units of Botox spreads for a given individual:


Since men’s facial muscles tend to be larger and stronger, 20 units may treat a smaller area on a man versus a woman with smaller, delicate facial muscles.


Younger patients tend to need fewer units of Botox to achieve wrinkle relaxation. As skin elasticity and muscle mass decrease with age, 20 units may go slightly further in an older patient.

Muscle Mass and Strength

Patients with larger, thicker, or more active facial muscles require more Botox units to relax the muscles fully. The same 20 units treats a smaller area of a muscular face versus a delicate one.

Wrinkle Severity

Twenty units spreads further when treating fine dynamic lines versus deep wrinkle etching. Deep wrinkles often need higher doses for optimal smoothing.

Treatment Goals

Patients desiring maximum wrinkle freezing may need higher doses and fewer treatment areas per vial. Those wanting subtle enhancement can spread 20 units over more areas for light muscle relaxation only.

Injector Experience

The skill and experience of the injector also impacts how far 20 units may spread. Inexperienced injectors often under-inject, so their 20 units may cover less area versus an expert injector using the precise minimum effective dose.

How Many Areas Can 20 Units Treat?

As a general guideline, 20 units of Botox can optimally treat 1-2 areas of the upper face, such as:

– Forehead wrinkles
– Frown lines between the brows
– Crow’s feet on both eyes or more significantly on one eye

For smaller or delicate areas like the nose, lips, or neck, 20 units may stretch to treat 3-4 zones:

– Bunny lines on the nose
– Smoker’s lines above the upper lip
– Neck bands
– Downturned mouth corners

However, for optimal results in each area, more units per area or treatment at the next appointment may be recommended. The injector customizes the treatment plan based on the patient’s unique needs and facial anatomy.

Results: What to Expect from 20 Units of Botox

When used properly, 20 units of Botox produces light to moderate wrinkle reduction and muscle relaxation in the treated areas. Patients notice a softening in lines while still retaining some natural facial expressions.

With 20 units divided over multiple areas, patients see subtle improvements versus dramatic wrinkle freezing. This provides an excellent starting point to gradually increase Botox at follow-up visits for optimal effects and safety.

It takes 2-14 days to see the final results. Effects last approximately 3-6 months as muscles gradually regain strength and wrinkles return. Maintenance appointments every 3-4 months continue relaxing the muscles to sustain smooth, youthful results long-term.

Safety and Side Effects

When performed correctly by an experienced medical professional, a dose of 20 Botox units is generally quite safe with minimal risks of complications:

– Mild pain, swelling, redness at the injection sites
– Minor bruising around injection sites
– Temporary headache, especially first time patients
– Slight eyelid drooping if too close to the eye area
– Asymmetry if one side treated more than the other

Using the minimal doses, proper injection techniques, and precise placements minimize these potential side effects from Botox. Choosing an expert injector further reduces risks for the best results.


In summary, 20 units of Botox can provide moderate treatment for 1-2 areas of the upper face such as the forehead, frown lines, and/or crow’s feet. For delicate areas around the eyes, nose, mouth, and neck, 20 units may spread to relax 3-4 zones subtly. However, more dramatic smoothing may require higher doses per treatment area.

Precisely how far 20 units of Botox spreads depends on several individual factors. An experienced injector will evaluate each patient’s unique facial anatomy, muscle size, wrinkle severity, and treatment goals to determine the optimal number of units needed per area.

When administered properly, 20 units of Botox produce light to moderate wrinkle reduction with minimal risks or side effects. Overly aggressive freezing is avoided, allowing patients to still make some facial expressions. Regular maintenance every 3-6 months enables patients to gradually increase muscle relaxation for their desired level of smooth, youthful results over time.

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