Crow's Feet: What Wrinkle Relaxer Can (and Can't) Do
If you squint against the desert sun on your way into work, you already know where crow's feet come from — and if you live anywhere near Henderson or Las Vegas, you're squinting a lot. Patients ask me all the time whether wrinkle relaxer actually does anything for those fine lines that fan out from the outer corner of the eye, or whether it's just marketing. It's a fair question, and it's one with a genuinely well-researched answer. Botox-type treatments for crow's feet (technically called lateral canthal lines) are among the most heavily studied cosmetic injectable indications there are, with an FDA approval specifically for this area. Here's what that research actually shows, in plain language, plus how to think about whether it's worth it for you.
Why Crow's Feet Form in the First Place
Crow's feet aren't caused by any one thing — they're the result of several factors layering on top of each other over time:
• Repeated muscle contraction. Every time you smile, squint, or laugh, the orbicularis oculi muscle around your eye contracts, folding the thin skin above it. Do that thousands of times a year and the fold starts to stay put.
• Sun exposure. Henderson and Las Vegas sit under some of the highest UV indexes in the country most of the year. UV light breaks down collagen and elastin, and it also makes people squint more, which compounds the muscle-contraction factor above.
• Thinning, less elastic skin. The skin around the eyes is already thinner than skin elsewhere on the face, and it naturally loses collagen and elasticity with age, so it creases more easily and springs back more slowly.
• Dehydration and dryness. Dry skin shows fine lines more readily, especially in a low-humidity desert climate.
• Genetics. Skin thickness, natural muscle tone around the eyes, and how early lines show up all vary quite a bit from person to person.
How Wrinkle Relaxer Targets the Eye Area
Wrinkle relaxer (onabotulinumtoxinA and similar neuromodulators) works by temporarily blocking the nerve signal that tells the orbicularis oculi muscle to contract. It doesn't fill in lines or add volume — it simply reduces how forcefully that muscle folds the skin above it every time you smile or squint. With the muscle contracting more gently, the skin has a chance to lie smoother, and over the following one to two weeks, existing lines visibly soften. The diagram below walks through that process step by step.
What the Research Shows
This is one of the better-studied areas in cosmetic medicine, which is part of why I'm comfortable recommending it. A few of the key findings:
• A 445-patient, multicenter, placebo-controlled trial found that 66.7% of onabotulinumtoxinA-treated patients were rated as treatment responders by investigators at Day 30, compared with just 6.7% of patients who received placebo (p<0.001). Patients themselves reported similarly high satisfaction — 60.1% said they were satisfied or very satisfied with their appearance, versus 7.5% in the placebo group. Improvement was still holding at Day 150 for many patients (Carruthers et al., Dermatologic Surgery, 2014).
• The same trial measured duration of effect at a median of about 118 days (just under 4 months) for patients who responded well, and reported that side effects were mild and similar in frequency to placebo — the most common was headache, occurring in a small minority of patients, with no treatment discontinuations.
• A 2025 review of botulinum toxin research for facial wrinkles confirmed consistently higher responder rates versus placebo across multiple trials, and noted that injection technique matters — placing injections roughly 1.5 to 2 centimeters lateral to the outer corner of the eye, and using four injection points rather than three, has been linked to higher patient satisfaction without an increase in side effects. This review put typical effect duration at 3 to 4 months (Ghalamghash, medRxiv preprint, 2025).
• The American Society of Plastic Surgeons notes that crow's feet are one of the FDA-approved indications for several botulinum toxin brands (including Botox, Dysport, Xeomin, Jeuveau, and Daxxify), all of which work through the same nerve-blocking mechanism, though they can differ somewhat in onset and duration.
I'll be honest about the limits here too: results vary from person to person depending on muscle strength, skin quality, and sun damage, and no injectable eliminates lines completely at rest if they've become etched in over many years of sun exposure — a wrinkle relaxer softens dynamic lines (the ones that appear with movement) most effectively.
Am I a Good Candidate?
• Good candidates typically have: visible lines when smiling or squinting (even if faint at rest), realistic expectations about softening rather than erasing lines, and no known allergy to the product's ingredients.
• Caution or non-candidacy includes: pregnancy or breastfeeding, certain neuromuscular conditions such as myasthenia gravis, active skin infection at the planned injection site, or a known hypersensitivity to botulinum toxin products.
• Because the injection sites sit close to the eye, technique and injector experience matter — precise placement helps avoid affecting nearby muscles that control eyelid position.
What to Expect: Timeline
• Days 1–3: Mild redness, small bumps, or pinpoint bruising at injection sites are possible and typically resolve quickly.
• Days 3–7: Early softening of lines with expression often begins.
• Day 14: Full effect is generally visible.
• 3–4 months: Typical duration of visible effect, per the research above, before a touch-up is needed to maintain results.
• Ongoing care: Daily sunscreen (especially important in our climate) and gentle eye-area skincare help protect results between sessions.
If you're curious whether wrinkle relaxer makes sense for your crow's feet specifically, the honest answer is that it depends on your skin, your goals, and how those lines behave when you're not smiling. That's exactly the kind of thing that's easier to talk through in person than to guess at from a blog post. If you're in the Henderson or Las Vegas area and want a straightforward, no-pressure assessment, I'd be glad to see you for a consultation.
About the Author
Bianca Camille Fong, APRN, FNP-BC is a board-certified Family Nurse Practitioner and the Founder & CEO of Blanqa Medspa in Henderson, NV, as well as Fong Precision Care. She provides wrinkle relaxer, dermal filler, microneedling, and a full range of aesthetic and wellness treatments, with a focus on safe, evidence-informed care and realistic outcomes.
Blanqa Medspa
1485 W Warm Springs Rd, Suite 109B, Henderson, NV 89014
Phone: 702-997-6764 | Email: hello@blanqaLV.com
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Sources
• Carruthers, A., Bruce, S., de Coninck, A., et al. (2014). Efficacy and Safety of OnabotulinumtoxinA for the Treatment of Crow's Feet Lines: A Multicenter, Randomized, Controlled Trial. Dermatologic Surgery, 40(11), 1181–1190.
• Ghalamghash, R. (2025). Efficacy of Botulinum Toxin Type A in Reducing Facial Wrinkles: A Comprehensive Review of Clinical Outcomes. medRxiv preprint 2025.05.14.25327581.
• American Society of Plastic Surgeons. Botulinum Toxin. plasticsurgery.org/cosmetic-procedures/botulinum-toxin.