Most people need 20 to 30 units of Botox for horizontal forehead lines and 20 to 40 total units for crow’s feet, putting the combined range at roughly 40 to 70 units for both areas. Your actual number depends on factors like muscle strength, gender, and how deep your lines are.
Forehead Lines: 15 to 30 Units
The forehead’s frontalis muscle is a broad, flat muscle that pulls upward every time you raise your eyebrows. Botox relaxes it just enough to soften the horizontal creases that form across the forehead over time. The manufacturer’s recommended dose is 4 units at each of five injection sites, totaling 20 units. In practice, providers use anywhere from 15 to 30 units depending on how strong your muscle contractions are and how deep the lines have become.
One important detail: the FDA-approved protocol pairs the forehead with the glabellar area (the vertical “11 lines” between your eyebrows), adding another 20 units across five sites there. That’s because treating the forehead alone, without also treating the frown lines, can create an unbalanced look or pull the brows into an unnatural position. If your provider recommends treating both, the forehead plus glabella combination typically runs 35 to 50 units total.
Crow’s Feet: 20 to 40 Units Total
Crow’s feet form in the thin, fan-shaped muscle that encircles each eye. When you smile or squint, this muscle contracts and creates the branching lines at the outer corners. The FDA-approved dose is 4 units at three injection points per side, totaling 24 units for both eyes. Many providers use 10 to 20 units per side, so total crow’s feet treatment ranges from 20 to 40 units depending on line severity.
Because the skin around the eyes is thinner than on the forehead, crow’s feet often respond well to moderate doses. Starting on the lower end lets your provider gauge your response and add more at a follow-up if needed, rather than overcorrecting on the first visit.
Why Men Typically Need More
Men’s facial muscles, particularly in the upper face, are thicker and generate stronger contractions. Clinical experience suggests men often require 1.5 to 2 times the number of units women need in the same area. A woman might get 10 to 20 units for the forehead, while a man could need 20 to 40 units for visible smoothing. The same pattern holds for crow’s feet: 15 to 20 units per side for men versus 10 to 12 for women. If the dose is too low relative to muscle mass, the effect wears off in weeks rather than months.
What the Full Treatment Costs
Most providers in the U.S. charge $10 to $25 per unit. At those rates, a combined forehead and crow’s feet treatment using 50 units would run $500 to $1,250 per session. Prices vary by city and by the credentials of your injector. Some clinics charge a flat rate per area rather than per unit, so it’s worth asking how your provider bills before your appointment.
When Results Appear and How Long They Last
Some people notice subtle changes within 3 to 4 days, but the full effect takes 10 to 14 days to develop. That two-week mark is when your provider would evaluate whether you need a touch-up. Results generally last about 3 months, though the actual duration depends on dosing. Lighter, more natural-looking doses may fade in 6 to 8 weeks, while higher doses can hold for over 6 months. Most people settle into a schedule of treatments every 3 to 4 months once they find the dose that works for them.
Risks of Getting the Dose Wrong
The most common issue with forehead Botox is brow drooping. This happens when too much product is used, when it’s injected too low on the forehead, or when it spreads beyond the intended area and over-relaxes the muscle that lifts your brow. Symptoms include a heavy feeling in the eyelids, a flattened brow arch, or a tired appearance. In rare cases, the drooping can create mild hooding over the upper eyelid.
The good news is that brow drooping from Botox is temporary. It typically improves within 3 to 6 weeks as the effect gradually wears off. This is one reason experienced injectors often start conservatively, especially with first-time patients, and add units at a follow-up rather than risk overcorrection. Crow’s feet injections carry less risk of visible complications because the muscle is smaller and more isolated, but poor placement can still cause asymmetry or a stiff look when smiling.
Putting the Numbers Together
Here’s a quick reference for typical unit ranges:
- Horizontal forehead lines: 15 to 30 units
- Frown lines (11s between brows): 15 to 25 units
- Crow’s feet: 10 to 20 units per side (20 to 40 total)
If you’re treating all three areas in one session, the total typically falls between 50 and 90 units. Treating just the forehead lines and crow’s feet without the frown lines puts you in the 40 to 70 unit range, though your provider may recommend including the glabella for a more balanced result. These are starting points. Your injector should assess your muscle strength, skin thickness, and aesthetic goals before settling on a final number.