Botox is administered through a series of small injections using a very fine needle, placed directly into specific facial muscles. A typical cosmetic session involves 5 to 6 injection points per treatment area, takes about 10 to 15 minutes, and requires no anesthesia. The process is more precise than most people expect, with exact dosages, depths, and angles tailored to each muscle being treated.
What Happens Before the Injections
Botox arrives as a freeze-dried powder in a sealed vial. Before it can be injected, a provider mixes it with sterile saline to create a liquid solution. A 100-unit vial gets 2.5 mL of saline, producing a concentration of 4 units per 0.1 mL. This standardized concentration means every injection delivers a consistent, measured dose.
Unopened vials are stored in a refrigerator between 36°F and 46°F and remain stable for up to 36 months. Once mixed, the solution must be used within 24 hours. Your provider will typically clean the treatment area with an antiseptic and may apply a topical numbing cream, though many people skip it since the needles are extremely thin.
The Injection Process
The standard needle for cosmetic Botox is a 30-gauge needle, roughly the width of a human hair. Injections are placed at very specific points that correspond to the underlying muscles responsible for the wrinkles being treated. The depth of each injection matters: some muscles require the needle to go deep into the muscle bulk, while others call for shallow placement just beneath the skin to avoid affecting nearby structures.
Each injection delivers a small, precise volume, typically 0.1 mL containing 4 units of Botox. The provider may ask you to frown, squint, or raise your eyebrows during the process to help locate the muscles and confirm proper placement. Most people describe the sensation as a brief pinch or sting that fades within seconds.
Where Injections Are Placed by Area
The three FDA-approved cosmetic treatment areas each have their own injection map.
Frown lines (between the eyebrows): Five injection points target three muscles. Two injections go into each corrugator muscle (the muscles that pull your brows together when you frown), and one goes into the procerus muscle (the small muscle at the bridge of your nose that creates horizontal lines). The medial injections are placed deep into the muscle, while the lateral ones are positioned more superficially and slightly above the brow line. Total dose: 20 units.
Forehead lines: Five injection points are spread across the frontalis muscle, the broad muscle that raises your eyebrows and creates horizontal forehead creases. This area is always treated alongside frown lines, bringing the combined dose to 40 units. Treating the forehead alone risks a heavy, droopy feeling because the frontalis works in opposition to the frown muscles.
Crow’s feet: Three injection points per side target the circular muscle around each eye. These six total injections deliver 24 units and are placed in the outer portion of the muscle to smooth the fan-shaped lines that appear when you smile or squint.
How Botox Works Once Injected
After injection, the toxin binds to nerve endings at the junction where nerves communicate with muscles. It enters the nerve cell and blocks the release of the chemical signal that tells the muscle to contract. Without that signal, the muscle relaxes and the overlying skin smooths out.
This process takes time. You can expect to see initial effects within 24 to 72 hours, though some people need up to five days for the full result to develop. The effects are temporary because nerve endings gradually form new connections, which is why results typically last three to four months before the muscle activity returns.
Injection Technique for Non-Cosmetic Areas
Botox is also injected into the neck, jawline, and trapezius muscles for both cosmetic contouring and medical purposes like chronic pain. These areas demand different techniques because the surrounding anatomy is more complex.
Neck and jawline injections are placed at the most superficial level, just beneath the skin, to avoid paralyzing deeper muscles involved in swallowing. Along the jawline, injections are angled at roughly 45 degrees from the corner of the mouth and kept above the marionette line to prevent unintended weakness in the lower lip. Trapezius injections for shoulder slimming or tension relief use a short, half-inch needle because the underlying ribs sit only about 2 cm below the skin surface in that area.
What to Do After Your Appointment
The first four hours after treatment are the most important. Stay upright, stick to gentle walking, and avoid bending over or lying flat. These precautions help keep the Botox in the intended muscles rather than migrating to adjacent areas.
For the first 24 hours, avoid strenuous exercise, heavy lifting, and any activity that significantly raises your heart rate or blood pressure. Skip yoga inversions, contact sports, and anything that puts pressure on your face. Heat exposure and activities that cause heavy sweating should also be postponed until you get the green light from your provider. After 24 hours, you can gradually return to your normal routine, starting with moderate cardio and lighter strength training before working back up to full intensity.
Who Should Not Get Botox
Botox is not appropriate for everyone. It is contraindicated for people with neuromuscular disorders like ALS, those who are pregnant or breastfeeding, anyone with a known allergy to botulinum toxin, and people with a history of keloid scarring at injection sites. Body dysmorphic disorder is also listed as a contraindication because the psychological condition can drive unrealistic expectations and compulsive pursuit of additional treatments.