Botox for Excessive Sweating (Hyperhidrosis)
Reviewed for medical accuracy against our Medical Review Board · Last updated 21 August 2026
Part of Botox Guides: Basics, Dosing and Safety
Botox is FDA approved for severe underarm sweating at 50 units per armpit, so 100 units for the pair. That is five times a frown line treatment, and it lasts far longer: the median duration of response in the approval trials was 201 days, not the three to four months cosmetic Botox gives. For hands, feet and face it is effective but off-label, and the label names what can go wrong.
Hyperhidrosis is the one use of botulinum toxin where the cosmetic mental model actively misleads you. The dose is much larger, the result lasts roughly twice as long, insurance sometimes pays, and the injection does not go into muscle at all. Almost everything you know about Botox from the aesthetics world has to be set aside.
1. What is actually approved, word for word
The wording on the BOTOX label matters more here than in any cosmetic use, because it is doing two jobs at once. It reads: for the treatment of severe primary axillary hyperhidrosis that is inadequately managed with topical agents.
Three words in that sentence are gates:
- Severe. Not "more than I would like". There is a scoring scale for this, and it is in section 3.
- Primary. Sweating that is the condition itself, not sweating caused by something else. This is the distinction in section 2, and it is the one that can matter medically rather than just financially.
- Axillary. Underarms. Not palms, not soles, not scalp, not face. The label is explicit that safety and effectiveness for hyperhidrosis in other body areas have not been established.
- Inadequately managed with topical agents. You are expected to have tried a prescription antiperspirant first and found it insufficient. This is also, not coincidentally, what most insurers ask you to document.
Meeting all four is what separates a treatment that is straightforward to get funded from one you will be paying for yourself.
2. The test that has to come first
This is the part almost no article on this subject mentions, and it is the part with actual medical consequences. The label instructs that patients should be evaluated for potential causes of secondary hyperhidrosis, giving hyperthyroidism as its example, so that treatment does not suppress the symptom without diagnosing the disease underneath it.
Read that again in plain terms: excessive sweating can be a symptom. An overactive thyroid, diabetes, some infections, some lymphomas, the menopause, and a long list of medications all cause it. Injecting the underarms will reduce the sweat regardless of the cause. If the cause was thyroid disease, you have now made the most visible sign of it go away while leaving the disease itself untreated.
The practical signals that point toward a secondary cause rather than primary hyperhidrosis are worth knowing before you walk in:
- It started suddenly, in adulthood. Primary hyperhidrosis usually begins in childhood or the teens.
- It is generalised rather than focal. Primary hyperhidrosis is concentrated in specific sites: underarms, palms, soles, scalp.
- It happens during sleep. Primary hyperhidrosis characteristically stops when you are asleep. Night sweats point elsewhere.
- It comes with weight loss, fever, a racing heart or new fatigue.
If any of those describe you, the right first appointment is with a doctor about the sweating, not with an injector about the Botox. A clinic that offers to treat underarm sweating without asking a single question about when it started or whether it wakes you up is not following the label.
3. The four point scale that decides everything
Severity here is not a judgement call, it is a score. The approval trials used the Hyperhidrosis Disease Severity Scale, a four point scale where 1 is "underarm sweating is never noticeable and never interferes with my daily activities" and 4 is "underarm sweating is intolerable and always interferes with my daily activities".
The trials enrolled people scoring 3 or 4, who also produced at least 50 mg of sweat in each armpit at rest over five minutes. Duration of response was then measured as the number of days until a patient returned to a score of 3 or 4.
Two things follow from that, and both are useful to you:
- A score of 3 or 4 is the evidence base. If you are a 1 or a 2, you are outside the population the treatment was approved in, and both the label and your insurer will treat you differently.
- The scale is self-reported, and it is short enough to answer honestly before your appointment. Deciding your own score in advance means the conversation starts from your own words rather than from a form filled in for you.
4. The iodine and starch test that maps your sweat
The label includes instructions for something called Minor's iodine-starch test, and it is used to find the area that actually needs injecting rather than guessing at the shape of the armpit. Iodine is applied, starch is dusted over it, and wherever sweat appears the two react and turn dark. The result is a literal map of your own sweat distribution.
The preparation the label asks for is specific and easy to get wrong: shave your underarms, and stop using any deodorant or antiperspirant for 24 hours before the test. Turn up having applied antiperspirant that morning and the map will be wrong, which means the injection pattern based on it will be wrong too.
Not every clinic performs the test. It is worth asking whether yours does, because the alternative is injecting a standard grid across an assumed area, and sweat distribution is not the same shape in everybody.
5. Five times a cosmetic dose
The approved dose is 50 units per armpit. Both sides is 100 units.
Set that against the cosmetic doses on the BOTOX Cosmetic label and the gap is the whole story:
| Treatment | Approved dose | Relative to frown lines |
|---|---|---|
| Frown lines (glabellar) | 20 units | 1x |
| Forehead lines with frown lines | 40 units | 2x |
| Crow's feet (lateral canthal) | 24 units | 1.2x |
| Underarm sweating, both sides | 100 units | 5x |
A single 100 unit vial, in other words, is one hyperhidrosis treatment. That is why the pricing conversation goes differently, and why per-unit pricing is often abandoned entirely for this treatment in favour of a flat fee. Our units guide and calculator covers how unit counts work across every area, and the underarm figure is the largest on the list.
6. Into the skin, not the muscle
Cosmetic Botox goes into muscle. Hyperhidrosis Botox does not, and this is a real difference rather than a technicality. The target is the sweat glands in the skin, so the injection is intradermal.
The label is unusually prescriptive about how:
- A 30 gauge needle, which is fine.
- 50 units diluted into 2 mL, spread across 10 to 15 separate injection sites per armpit, roughly 1 to 2 cm apart.
- Each one to a depth of about 2 mm, at a 45 degree angle to the skin, bevel up, to keep the dose in the skin and stop it leaking back out.
Ten to fifteen injections per side means 20 to 30 in a session. This is the honest answer to "does it hurt": there are a lot of them, they are shallow, and the underarm is sensitive. Most clinics offer topical numbing cream or ice, and it is reasonable to ask for it rather than wait to be offered.
The shallow depth is also why the muscle-related risks that dominate cosmetic Botox largely do not apply here. There is no muscle underneath that you need for expression.
7. Why it lasts twice as long
This is the number that should change your planning, and it is the one most articles get wrong by repeating the cosmetic figure.
In the approval trials, the median duration of response after a first treatment was 201 days. That is a little under seven months. Among people who went on to have a second treatment, the median duration was similar to the first, so the effect does not shorten with repetition.
Against three to four months for a frown line treatment, that reframes the annual cost completely:
| Treatment | Typical duration | Treatments a year |
|---|---|---|
| Frown lines | 3 to 4 months | 3 to 4 |
| Underarm sweating | About 6 to 7 months (201 day median) | Roughly 2 |
So although a single hyperhidrosis session costs several times a cosmetic one, you need it about half as often. The label is also clear on when to repeat: when the clinical effect of the previous injection diminishes, rather than on a fixed calendar.
8. What it costs at real published rates
Most clinics quote hyperhidrosis as a flat fee rather than per unit, which makes it hard to tell whether you are being quoted fairly. So here is the 100 unit dose priced at the per-unit rates clinics actually publish in the cities we verify, which gives you a floor to compare any flat fee against.
| City | Published rate per unit | 100 to 100 units |
|---|---|---|
| Atlanta, GA | $9 to $15 | $900 to $1,500 |
| Austin, TX | $11 to $13.5 | $1,100 to $1,350 |
| Charleston, SC | $9.99 to $13 | $999 to $1,300 |
| Charlotte, NC | $9 to $15 | $900 to $1,500 |
| Chicago, IL | $9 to $15 | $900 to $1,500 |
| Denver, CO | $10 to $16 | $1,000 to $1,600 |
| Las Vegas, NV | $10 to $16 | $1,000 to $1,600 |
| Nashville, TN | $10 to $14 | $1,000 to $1,400 |
| Philadelphia, PA | $10 to $15 | $1,000 to $1,500 |
| Phoenix, AZ | $9.99 to $13 | $999 to $1,300 |
| Raleigh, NC | $13 to $14 | $1,300 to $1,400 |
| Salt Lake City, UT | $9.8 to $14 | $980 to $1,400 |
| San Antonio, TX | $10.5 to $12.5 | $1,050 to $1,250 |
| Scottsdale, AZ | $10.5 to $13.5 | $1,050 to $1,350 |
| Tampa, FL | $10 to $18 | $1,000 to $1,800 |
If a clinic's flat fee is far above the figure for your city, the gap is either injector time, the iodine-starch test, or margin, and it is fair to ask which. If it is far below, ask how many units the price covers, because 50 units total rather than 50 per side is a real and common way for a quote to look cheap. Our Botox price guide covers the rest of what moves the number.
9. Insurance, and the gate you have to fail first
Unlike almost every cosmetic use, this one is often covered, because it treats a diagnosed medical condition with an on-label treatment. But coverage turns on a specific sequence, and the sequence is visible in the indication itself: inadequately managed with topical agents.
In practice that means insurers want to see, documented in your notes:
- A diagnosis of primary focal hyperhidrosis, with secondary causes considered and excluded.
- A severity score, usually 3 or 4 on the scale in section 3.
- A documented trial of prescription strength aluminium chloride antiperspirant that either failed or could not be tolerated. This is the step people skip, and it is the one that gets claims denied.
- Sometimes a trial of an oral anticholinergic as well, depending on the plan.
The order matters. A prescription antiperspirant tried and documented before you ask about Botox is worth more to your claim than the same antiperspirant tried afterwards. If your sweating is severe enough to be reading this, starting that paper trail at your next GP or dermatologist appointment costs you nothing and may save you the full fee.
Botox for chronic migraine works the same way and is the other use where insurance is genuinely routine. We cover that gate in detail in the chronic migraine guide. Compare that with masseter treatment for jaw clenching, where coverage is far harder to obtain because the aesthetic benefit muddies the medical claim.
10. Hands, feet and face: off-label, and why that matters here
Botox does work on palms, soles, scalp and face. It is used for all of them. But this is one of the few places where "off-label" carries a warning printed on the label itself, and it is worth quoting the substance of it: the label states that weakness of hand muscles may occur in patients treated for palmar hyperhidrosis, and drooping of the eyelid may occur in patients treated for facial hyperhidrosis.
That is the manufacturer naming the specific complication for each specific site. It changes the calculation:
- Palms. The muscles that pinch and grip sit directly under the skin you are injecting. Temporary weakness of fine pinch grip is a recognised consequence. For a pianist, a surgeon, a climber or anyone whose hands are their livelihood, that is a real trade rather than a footnote. Palmar injection is also markedly more painful than underarm, and often needs a nerve block rather than numbing cream.
- Face and scalp. The muscle that holds your eyelid up is nearby, and the label says so. Facial sweating is the site where the aesthetic complication risk is highest.
- Soles. Painful to inject, and the results are generally reported as less reliable than underarm.
None of that makes these treatments unreasonable. It makes injector experience matter far more than it does for underarms, where the anatomy is forgiving. If you are having palms done, ask specifically how many palmar cases the person injecting has treated, and check their license yourself using our 50 state verification guide.
11. What it does not do
Three honest limits, none of which usually appear in clinic marketing:
It does not cure anything. It blocks the signal to the sweat glands in the area injected. The glands are intact, the condition is unchanged, and when the toxin wears off the sweating returns to exactly where it was. This is a management treatment repeated indefinitely, not a fix.
It only treats where the needle goes. Injected underarms will stop sweating. Nothing else changes. If your hands and underarms both sweat, treating one does nothing for the other, and both being treated means two off-label decisions and two costs.
Compensatory sweating is the honest open question. Patients often ask whether blocking sweat in one place forces it out somewhere else. The strong version of this worry comes from surgical sympathectomy, where compensatory sweating is a well documented and sometimes severe outcome. With focal injection it is reported much less and much more mildly, and it is not listed as a common adverse reaction on the label. It is reasonable to ask your injector what they have seen rather than expecting a guarantee either way.
One thing that applies to every use of this drug regardless of site: the label carries a boxed warning about distant spread of toxin effect, with symptoms reported anywhere from hours to weeks after injection, and swallowing and breathing difficulties described as potentially life threatening. Hyperhidrosis doses are large. Knowing that difficulty swallowing or breathing after any botulinum toxin injection is an emergency rather than a side effect to wait out is not scaremongering, it is the label.
12. What to ask before you agree
- When did my sweating start, and have you ruled out a cause other than primary hyperhidrosis? If nobody asks you this, ask them.
- What is my severity score, and are you recording it? It is what a future insurance claim rests on.
- How many units per side, and is that 50 each or 50 total? Get the number, not the package name.
- Do you perform the iodine-starch test, or inject a standard pattern?
- Is this being billed as a medical treatment, and have we documented a failed topical trial?
- What numbing do you offer, given this is 20 to 30 injections?
- If you are treating my palms: how many palmar cases have you done, and what do you tell patients about grip strength?
- When should I expect to come back, and do you charge the same for a repeat?
Sweating starts to reduce within a few days to a couple of weeks. If nothing has changed at all four weeks after treatment, that is worth reporting rather than accepting, because dose and placement can both be adjusted next time.
Frequently asked questions
Is Botox FDA approved for sweating?
How many units of Botox do I need for underarm sweating?
How long does Botox for sweating last?
Does insurance cover Botox for hyperhidrosis?
Does Botox for sweating hurt?
Can Botox be used for sweaty hands?
Will treating my underarms make me sweat somewhere else?
Does Botox cure hyperhidrosis?
Should I see a doctor before getting Botox for sweating?
Is Botox or miraDry better for underarm sweating?
