Botulinum toxin (Botox)

Also known as: Botox, Dysport, Xeomin, Jeuveau, Daxxify, onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA

Botulinum toxin type A is a purified protein injected into facial muscles to soften expression lines, sold under brand names including Botox, Dysport, Xeomin, and Jeuveau. It is the single best-studied cosmetic injectable, with dozens of randomized placebo-controlled trials and multiple meta-analyses behind its FDA-approved uses for frown lines, crow's feet, and forehead lines. Effects are temporary, typically 3 to 4 months, and the safety record over roughly 20 years of cosmetic use is strong when injected by trained practitioners. Newer intradermal uses for pore size and oiliness are far less proven.

How it works

The toxin blocks release of acetylcholine, the chemical nerves use to tell muscles to contract. Injected into a specific muscle, it temporarily weakens that muscle, so the overlying skin stops creasing with each expression and existing dynamic wrinkles soften. Nerve endings recover over a few months, which is why the effect wears off and treatment must be repeated.

What the evidence says, claim by claim

These are the results measured in studies, not the results shown in ads. Where the research is weak, the grade says so.

For wrinkles and fine lines

Strong evidence

A meta-analysis of 7 randomized placebo-controlled trials with 1,474 subjects found investigator-rated response rates dramatically higher with botulinum toxin than placebo for glabellar (frown) lines, with no increase in adverse events versus placebo. A 2023 network meta-analysis of randomized trials compared the approved formulations and found all effective for moderate to severe glabellar lines. For crow's feet, two phase 3 trials totaling 1,362 patients plus a separate multicenter randomized trial showed significant improvement with a 24-unit dose, with effects lasting roughly 3 to 5 months. Frown lines, crow's feet, and forehead lines are all on-label FDA-approved uses.

Multiple randomized controlled trials or a meta-analysis support this use. The effect is real and repeatable.

Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Glabellar Lines: A Meta-Analysis of Randomized, Placebo-Controlled, Double-Blind Trials (Plastic and Reconstructive Surgery, 2015; meta-analysis)
Efficacy and Safety of Botulinum Toxin Type A for Treatment of Glabellar Lines: A Network Meta-Analysis of Randomized Controlled Trials (Aesthetic Plastic Surgery, 2023; meta-analysis)
Efficacy and safety of onabotulinumtoxinA for treating crow's feet lines alone or in combination with glabellar lines (Dermatologic Surgery, 2015; RCT)

For enlarged pores

Limited evidence

Very shallow intradermal injection of dilute botulinum toxin (often marketed as microbotox or microtox) is used off-label to shrink pores and cut oil production. A 2025 randomized split-face trial in 30 patients found reduced sebum and pore scores at 1 month, and a randomized placebo-controlled trial showed reduced scalp sebum for about 3 months. Studies so far are small and short, effects fade within 3 to 4 months, and this use is entirely off-label.

Only small, short, or lower-quality studies exist. Treat marketing claims about this use with caution.

Comparison of Intradermal Versus Microneedling-Assisted Botulinum A Toxin Injection for Enlarged Facial Pores: A Randomized Clinical Trial (Journal of Cosmetic Dermatology, 2025; RCT)
Intradermal Botulinum Toxin A Injection for Scalp Sebum Secretion Regulation: A Multicenter, Randomized, Double-Blinded, Placebo-Controlled, Prospective Study in Chinese Subjects (Aesthetic Surgery Journal, 2023; RCT)

Risks and what can go wrong

Common side effects are injection-site bruising, swelling, and headache, all short-lived. Eyelid or brow droop (ptosis) occurs in roughly 1 to 5 percent of upper-face treatments and resolves as the toxin wears off, usually within weeks to months. Placement is skill-dependent: an experienced injector matters more for avoiding droop and asymmetry than for almost any other complication. Serious spread of toxin effect is extremely rare at cosmetic doses. Avoid during pregnancy and breastfeeding, and in people with neuromuscular disorders such as myasthenia gravis or ALS.

The practical details

Typical US pricing is 10 to 20 dollars per unit; a glabellar treatment uses about 20 units and crow's feet about 24 units, so common sessions run 300 to 600 dollars. Results appear in 3 to 7 days, peak around 2 weeks, and last 3 to 4 months, so most people treat 3 to 4 times per year. Botox, Dysport, Xeomin, Jeuveau, and Daxxify are FDA approved for glabellar lines; Botox is also approved for crow's feet and forehead lines. Pore, oil, and jawline slimming uses are off-label.