How Many Units of Botox Do I Need? A Dosing Guide by Area

Written by Cristina Borhani, MSN, NP. Medically reviewed by Korosh Borhani, D.O., board-certified emergency physician and Medical Director of Skin Bio. Last reviewed September 17, 2026. Instagram: @CristinaBorhani_NP

It is the question I get more than any other, usually before a patient has finished sitting down. How many units of Botox do I need? Fair question. That number determines your result, how long it lasts, and what you pay, and almost nobody explains where it comes from.

The real answer depends on your anatomy, your muscle strength, and what you want your face to still be able to do. But “it depends” is a non-answer. So here is how I actually think about dosing, area by area, and why I dose the way I do.

First: a unit is not a universal measurement

This trips up almost everyone. A unit of Botox is not equivalent to a unit of Dysport, Xeomin, Jeuveau, or Daxxify. These products are not interchangeable and their units do not convert on any simple ratio. Dysport, for instance, is typically dosed at roughly two to three times the unit count for comparable effect.

So when you are comparing prices, ask which product is being used before you compare per-unit cost. Otherwise you are comparing dollars per ounce to dollars per pound. This is worth knowing in a market like Los Angeles, where per-unit pricing gets advertised aggressively and the product name is often in the fine print.

Why I use Botox

I am brand loyal, and I will tell you why. Botox has the longest track record and the deepest body of clinical research of any neurotoxin available. It has been studied in more patients, across more indications, over more years than anything else in the category, and it currently holds four FDA-approved aesthetic indications: frown lines, forehead lines, crow’s feet, and platysma bands.

That matters for one practical reason. When a product has been studied that thoroughly, I know what to expect from it. Onset window, duration curve, dose-response, safety profile at specific doses in specific muscles. Predictability is not a small thing when you are injecting someone’s face.

Newer toxins may well prove excellent, and some already look promising. I would still rather give you the most predictable result available than the newest one.

How many units of Botox by area

Below are the doses from the FDA-approved labeling, which come directly out of the clinical trials. Below that are the areas treated off-label, meaning the dose comes from published literature and practice experience rather than an FDA indication. Off-label use is standard and appropriate in aesthetics, but you should know which is which.

FDA-approved areas

The forehead number is the one that raises eyebrows, so to speak. The FDA-approved dose for forehead lines is not 20 units of frontalis on its own. It is 20 units into the frontalis plus 20 units into the glabella, for 40 total, and the glabellar portion is written into the label specifically to reduce the risk of the brow dropping.

The reason is mechanical. Your frontalis lifts your brow. The muscles between your brows pull it down. Weaken only the lifter and you get a heavy, hooded brow, which is the complaint I hear most often from patients who were treated somewhere else. Treating both keeps the balance. If someone offers to do “just your forehead” for ten units, this is why I would ask questions.

Platysma bands were approved in 2024, the first Botox indication below the face. It has genuinely changed how I approach jawline definition in patients who were previously told their only option was filler or surgery.

Off-label areas and what I use

The masseter range is wide for a reason. A patient with a strong clench habit and a visibly square jaw may need 30 units per side. Someone slimmer may need 15. This is also the area where patients get impatient, because you are waiting for muscle to atrophy rather than simply relax, and that takes weeks longer than it does on the face.

Why I dose fully

There is a trend toward micro-dosing, sprinkling a few units around and calling it prevention. I understand the appeal. Lower commitment, friendlier price.

I dose according to what Allergan actually studied, and the reasoning is simple. Those trial doses are not arbitrary numbers. They are the doses at which the duration data was generated. When you read that Botox lasts three to four months, that is three to four months at the studied dose. Halve the dose and you do not get half the result for half the price. You typically get a weaker result that fades meaningfully sooner, and sometimes an uneven one, because partial weakening of a muscle does not distribute itself neatly.

What happens next is the part worth understanding. Underdosed patients come back sooner. The result softens at six or seven weeks instead of twelve, so they book a touch-up, then another, and they end up injected more often in smaller increments, chasing a result they never fully got the first time.

That matters beyond your calendar. Botox’s own labeling advises using the lowest effective dose at the longest feasible intervals between treatments, because more frequent injections are one of the factors associated with developing antibodies to the toxin. That is what people mean when they say Botox “stopped working” for them. It is uncommon and not something most patients need to worry about. But a dosing approach that has you back in the chair every seven weeks is working against that guidance, not with it.

An adequate dose on a sensible three-to-four-month schedule is the more predictable approach and, in my experience, the better value. You pay for more units and you buy months instead of weeks.

What changes your number

Muscle mass. Stronger muscles need more product. This is the single biggest variable, and it is why I watch you move before I pick a number.

Sex. Men generally have greater muscle bulk in the glabella and frontalis and often require noticeably higher doses, sometimes close to double in the glabella, for the same softening.

Treatment history. Patients treated consistently for years may need slightly less over time as the muscles weaken with disuse. First-timers with never-treated muscles usually need the full dose.

Your goal. Wanting complete stillness is a different dose than wanting softened lines with expression preserved. Tell me which one you want. Both are legitimate and I would rather know than guess.

Your metabolism. Some people break the product down faster. If you are consistently getting eight to ten weeks at a full dose, that is worth discussing rather than accepting.

Risks, and who should not have this

Botox is a prescription medication and carries a boxed warning about the distant spread of toxin effect. Reported side effects include bruising, headache, brow or eyelid droop, asymmetry, and, in the crow’s feet area, temporary dry eye or a heavy-feeling lower lid. Most of these are temporary and resolve as the product wears off, but “temporary” can still mean weeks.

Botox is contraindicated if you have an infection at the injection site or a known hypersensitivity to any botulinum toxin preparation. I do not treat patients who are pregnant or breastfeeding. If you have a neuromuscular disorder such as myasthenia gravis, Lambert-Eaton syndrome, or ALS, you need a conversation with your neurologist before anyone injects you, because these conditions can amplify the effect of the toxin.

There are also patients I turn away for reasons that have nothing to do with safety. If your concern is skin texture, crepiness, or volume loss, a neurotoxin is the wrong tool and will disappoint you. Sometimes the honest answer is filler, sometimes it is a resurfacing treatment, and sometimes it is a skincare plan and nothing else that day.

What to expect at your appointment

Your first visit is mostly assessment. I will have you frown, raise your brows, squint and smile so I can see how your muscles actually move at rest and in motion. Then I map your injection points and give you a specific unit count and price before anything happens. No surprises at checkout.

Movement starts to soften around day three to five, with the full result at about two weeks. I schedule a two-week follow-up for new patients so we can look at the result together and document your dose for next time. That record is how your second treatment comes out better than your first.

Plan on returning around the three-to-four-month mark. Coming in before your movement has fully returned is the most reliable way to keep your results consistent over time.

Follow along on Instagram: @CristinaBorhani_NP and @skinbio.co

This article is educational and is not individual medical advice. Botox is a prescription medication, and treatment requires evaluation by a licensed provider. If you would like to discuss whether it is appropriate for you, get in touch.