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A Complete Guide to Recommended Underarm Odor Treatments

Causes of Underarm Odor (Axillary Osmidrosis) and Treatment Options by Odor Severity

Are you worried that you might have underarm odor (axillary osmidrosis)?

Axillary osmidrosis is not visible to the eye, and it can be difficult to notice the odor yourself. As a result, you may unknowingly be causing discomfort to colleagues or family members without realizing it.

Rather than continuing to live with that anxiety, let’s take a positive step toward addressing the root causes of axillary osmidrosis through treatment or other measures.

In this article, we explain how to self-check your symptoms and outline specific treatment options.

Treatment technology has advanced considerably, and there are now treatment methods that can be performed without hospitalization, as well as surgical procedures designed to minimize scarring and disruption to daily life.

If you are concerned about underarm odor, we hope this article will be a helpful resource.

What Is Underarm Odor (Axillary Osmidrosis)? | A Condition Causing Strong Underarm Odor Due to Sweat Secreted by the Apocrine Glands

Axillary osmidrosis refers to the condition of unpleasant odor emanating from the underarms.

Formally defined as axillary osmidrosis, it is characterized by a strong odor that can be detected even without raising the arms.

The odor originates from the oxidation of sweat produced by the apocrine sweat glands in the underarms. Because perspiration intensifies the odor, symptoms tend to be more noticeable in summer, after exercise, or in other situations where sweating occurs.

The condition often first appears around puberty, and in many cases the symptoms become less noticeable with age.

Axillary osmidrosis is estimated to affect approximately 10% of the Japanese population — a relatively low proportion globally — yet many people are bothered by the characteristic odor, and a wide range of products aimed at managing it have become available.

Research into axillary osmidrosis treatment has advanced, and in recent years treatment has enabled significant improvement in most cases.

What Does Axillary Osmidrosis Smell Like? Characteristic Symptoms Explained

The odor associated with axillary osmidrosis is often described in the following ways:

・A sulfur-like smell
・A spicy, pungent smell reminiscent of strong seasonings
・A sharp smell similar to onions
・A smell resembling pencil lead

If you notice an odor with these characteristics, there is a possibility you may have axillary osmidrosis.

In addition, the more of the following physical signs that apply to you, the higher the likelihood of axillary osmidrosis:

・Wet or moist earwax
・Yellowing of underwear or clothing
・One or both parents have axillary osmidrosis
・Excessive underarm sweating

If you are concerned about whether you have axillary osmidrosis, start by checking how many of the above items apply to you.

Why Does Axillary Osmidrosis Cause Odor?

Sweat secreted by the apocrine glands contains components such as iron, fatty acids, and ammonia, giving it a slightly viscous quality and making it the primary source of the distinctive odor associated with axillary osmidrosis.

Sweat glands are divided into apocrine glands and eccrine glands, and the composition of the sweat they produce differs between the two.

Sweat from the eccrine glands is approximately 98% water and produces little to no odor.

Apocrine glands, on the other hand, secrete sweat that contains fatty acids. These fatty acids are broken down by bacteria on the skin into shorter-chain fatty acids, eventually converting into 3-methyl-2-hexenoic acid.

The substance known as “3-methyl-2-hexenoic acid” is considered to be responsible for the odor characteristic of axillary osmidrosis.

The Relationship Between Axillary Osmidrosis and Earwax

Moist earwax is considered an indicator of a higher likelihood of axillary osmidrosis.

The ear canal also contains apocrine glands — the same glands associated with axillary osmidrosis — and the number of these glands influences the consistency of earwax.

A greater number of apocrine glands leads to more secretion, which is why moist earwax may be associated with a higher likelihood of axillary osmidrosis.

If the earwax has a sticky, caramel-like texture, the possibility of axillary osmidrosis may be even higher.

However, even among people with moist earwax, the rate of axillary osmidrosis is estimated at around 80%, meaning moist earwax does not necessarily indicate the condition.

In particular, for women, the correlation between earwax type and odor severity is not as strong as it is for men.

Rather than relying on earwax alone, consider multiple factors when assessing whether you may have axillary osmidrosis.

What Causes Axillary Osmidrosis? Diet and Lifestyle Habits Also Play a Role

The causes of axillary osmidrosis involve both genetic factors and lifestyle habits.

The main causes can be grouped into the following three categories:

・Inheriting a larger number of apocrine glands through genetics
・Increased apocrine gland secretion due to the influence of sex hormones
・Disrupted lifestyle habits, which can act as a trigger for the onset of axillary osmidrosis

Let’s look at each one in turn.

Cause ①: Inheriting a Greater Number of Apocrine Glands Through Genetics

Inheriting a larger number of apocrine glands from one’s parents is one contributing factor.

It is well established that axillary osmidrosis can be inherited. If one parent has the condition, there is approximately a 50% chance it will be passed on to their child.

If both parents have axillary osmidrosis, the likelihood of inheritance rises to around 80%, indicating a significant genetic influence.

The greater the number of apocrine glands and the larger their size, the stronger the associated odor tends to be.

While inheritance is not guaranteed, if one or both parents have axillary osmidrosis, the probability that their child will also develop the condition is higher.

Cause ②: Increased Apocrine Gland Secretion Due to Sex Hormone Influence

The amount of secretion from the apocrine glands is determined by their size and number, which in turn affects the intensity of odor.

Axillary osmidrosis most commonly develops around puberty, when shifts in sex hormone balance cause the apocrine glands to enlarge and become more active.

While the size and number of apocrine glands are determined by genetics, axillary osmidrosis does not typically manifest immediately after birth.

The age of onset varies from person to person; however, onset during puberty — when sex hormone levels are more likely to fluctuate — is particularly common.

Cause ③: Disrupted Lifestyle Habits Can Act as a Trigger

Irregular lifestyle habits can also contribute to the onset of axillary osmidrosis.

When the body is under stress, the apocrine glands may be stimulated, leading to increased sweat secretion.

Sweating when nervous — such as when speaking in front of others — is a familiar example of stress-induced perspiration that many people have experienced.

Furthermore, a lack of physical activity can make it harder for the body to sweat regularly, which may intensify underarm odor.

Without regular exercise, the body sweats less, allowing waste products to accumulate.

When sweating does eventually occur, these accumulated waste products are released all at once, which can result in a stronger odor.

Axillary Osmidrosis Severity Levels: Three Main Categories

Axillary osmidrosis can be broadly classified into three severity levels, ranging from mild to severe.

The characteristics of each level are as follows:

・Mild: Odor is only noticeable when the nose is brought close to the affected area
・Moderate: Odor is detectable when in close proximity or in an enclosed space
・Severe: Odor is strong enough for anyone entering the room to notice

If you are concerned about whether you may have axillary osmidrosis, use these descriptions to get a sense of where your symptoms might fall.

Mild: Odor Noticeable Only When the Nose Is Brought Close to the Affected Area

In mild cases, the odor is barely noticeable unless one gets close, and many individuals are unaware of it themselves.

For example, this level might describe someone who has never been told about the odor by others but notices a faint smell from their underarm when changing clothes and bringing their nose close to the area.

Over-the-counter antiperspirants can be helpful for managing mild symptoms, though those who are concerned may wish to consult a clinic sooner rather than later.

At this level, others are unlikely to find the odor unpleasant, and in most cases, only the person themselves is aware of it.

Some individuals may worry more than necessary; in such cases, it is worth considering whether the concern might relate to a separate condition called “olfactory reference syndrome” — a tendency to believe others perceive an odor when they do not.

Counseling can help ease these concerns, so consulting a healthcare provider is worth considering.

Of course, medical treatment for axillary osmidrosis is also available, so if you are concerned, we recommend speaking with a physician.

Moderate: Odor Detectable When in Close Proximity or in an Enclosed Space

When odor is noticeable when getting close to someone or in an enclosed space, this falls into the moderate category.

For example, this level might describe a situation where a faint odor is perceptible when in a confined space such as a train carriage and in close proximity to others.

In moderate cases, some people nearby may notice the odor, but it is generally not clear who the source is.

As long as you are not in very close contact with others or frequently in enclosed spaces, others are unlikely to notice.

However, on a hot summer day when wearing light clothing, others nearby may find the odor uncomfortable.

Since moderate axillary osmidrosis can cause discomfort to those around you, it is worth considering treatment as appropriate.

For mild to moderate cases, miraDry treatment is an option with relatively low physical burden.

Severe: Odor Strong Enough for Anyone Entering the Room to Notice

In severe cases, the odor is strong enough for anyone entering the room to notice.

For example, if a strong odor is detectable even when wearing a jacket and without being in a crowded space, this is indicative of severe axillary osmidrosis.

The odor can permeate a room, causing discomfort to many, and in enclosed spaces particularly, a significant number of people are likely to notice it.

Over-the-counter products are generally insufficient to manage this level of odor, and prompt medical treatment is advisable.

Removing or destroying the apocrine glands responsible for the odor can help reduce it significantly.

For concerns about underarm odor, please consult IC Clinic.

Living with the worry of axillary osmidrosis and constantly managing it can be exhausting.

IC Clinic offers free consultations for underarm odor treatment.

We propose treatment approaches suited to a range of individual needs, such as “I want to minimize scarring” or “I want to see results as soon as possible.”

To find the treatment approach that is right for you and move toward relief from axillary osmidrosis concerns, we encourage you to take advantage of our free consultation.

Three Types of Underarm Odor Treatment | Features and Approximate Costs

When focusing specifically on the underarm area, the appropriate treatment depends on whether you wish to address odor, excessive sweating, or both.

Each option has its own advantages and disadvantages, and costs can range widely from tens of thousands to several hundred thousand yen. It is therefore important to receive a consultation from an experienced physician and select the treatment approach that is right for you.

Here we explain three of the most common underarm odor treatment methods:

・Botox (botulinum toxin) injections
・Surgical treatment
・miraDry

Botox Injections: A Convenient Treatment Option for Those Seeking a Simple Approach

Botox injections require relatively little treatment time and are comparatively affordable, making them a convenient treatment option.

A medication is injected directly into the affected area to suppress nerve activity and reduce the amount of sweat produced.

This treatment is well suited to those who want a straightforward option they can access when needed.

Surgical Treatment (Excision Method): The Primary Option for Severe Cases

For patients with severe axillary osmidrosis, surgery is generally the first treatment to consider.

Surgical treatment can provide substantial improvement and has been performed for many years.

Several surgical techniques exist; at our clinic, we use the standard procedure known as the “excision method (skin-flap technique).”

After administering anesthesia, the affected area is surgically opened and the apocrine glands are directly removed.

miraDry: Non-Surgical Underarm Odor Treatment

miraDry involves minimal discomfort and is a treatment option that has been attracting attention for its potential to provide long-lasting results.

Microwave energy is applied to the underarm area to target and destroy the apocrine glands.

Temporary Management of Underarm Odor with Topical and Oral Medications

Topical and oral medications are also available as options for managing axillary osmidrosis.

However, these medications offer only temporary relief and do not address the underlying cause of axillary osmidrosis.

Medications may be prescribed by a physician or, in some cases, purchased at a pharmacy.

Topical Medications: Reducing Underarm Odor by Suppressing Perspiration

There are two main types of topical medications:

・Those that help reduce sweating
・Those that help suppress odor

Both types work by being applied directly to the affected area where sweating is most pronounced.

Topical antiperspirants typically contain aluminum chloride; as they may cause itching upon application, it is advisable to apply them using a tissue or similar material to limit contact to the target area.

Topical antibiotics are also effective. Applying them for 2 to 3 days to suppress odor can provide relief for approximately 1 to 2 weeks before reapplication is needed.

By reapplying the medication whenever symptoms return, axillary osmidrosis can be kept under control.

If topical medications alone are insufficient to manage odor, using oral medication in combination or wearing antibacterial clothing may also be helpful.

Oral Medications: Reducing Underarm Odor by Inhibiting Acetylcholine

Oral medications containing anticholinergic agents work by inhibiting acetylcholine, thereby reducing the amount of sweat the body produces.

The dosing schedule will be determined in consultation with your physician, but typically requires taking the medication 3 to 4 times per day. Effects generally appear within about one hour of taking the medication, so timing your doses accordingly is helpful.

One potential side effect of reducing sweating is a sensation of warmth in the body.

Long-term use may place a burden on the body, so for those seeking a more fundamental solution, treatments such as miraDry or surgery may be worth considering.

Self-Care Measures for Managing Underarm Odor

For those who want to address the root cause of axillary osmidrosis, medical treatment is recommended. However, if you are not yet in a position to pursue treatment — whether due to cost or a preference to try accessible measures first — the following approaches may help:

・Shower frequently / wipe away sweat regularly
・Remove or reduce underarm hair
・Use antiperspirants or deodorant products with antibacterial properties

Let’s look at each one in turn.

Measure ①: Shower Frequently / Wipe Away Sweat Regularly

Keep your body clean by showering regularly and wiping away sweat promptly.

Removing excreted waste products from the skin is an effective way to help reduce odor.

Showering is ideal where possible, but when you are out, thoroughly wiping the underarms — where sweat tends to accumulate — can also be sufficient.

Use clean handkerchiefs or wipes, and make sure to dry the area thoroughly — this is key.

Make a habit of wiping down whenever you notice perspiration.

Measure ②: Remove or Reduce Underarm Hair

Moisture and heat trapped by hair can contribute to odor. Removing or reducing hair in the underarm and intimate areas helps prevent sweat from becoming trapped and causing that issue, so it is particularly advisable to address areas with dense hair growth.

Hair removal also makes it easier to wipe away sweat, helping you maintain cleanliness more consistently.

Hair removal creams suitable for intimate areas are rarely available over the counter, so undergoing hair removal at a clinic is recommended for safety.

Measure ③: Use Antiperspirants or Antibacterial Deodorant Products

Antiperspirants can be helpful for managing mild odor.

Antiperspirants are products that can temporarily help reduce sweating. Their appeal lies in how they can be used in targeted situations — such as during summer when sweating is more likely, or before exercise.

Deodorants help reduce unpleasant odor by inhibiting the growth of odor-causing bacteria.

Products that also contain antiperspirant ingredients can help reduce the amount of sweat at the same time.

Both types are readily available at pharmacies.

These products come in various forms — including roll-on, spray, sheet, and cream — but the roll-on type is generally recommended for close contact with the underarm. Oronine, which has antibacterial properties, is also a popular choice.

Many products contain fragrance, so choose one that suits your preferences.

Measure ④: Wipe with Alcohol-Soaked Cotton

Wiping the affected area with alcohol-soaked cotton can help inhibit bacterial growth and keep the area consistently clean.

If cotton is not available, tissues or antibacterial body wipes can also be effective.

Do not reuse the same cloth or wipe; always use a fresh one each time.

After wiping, put on clean clothing and try to prevent sweat from transferring back to the fabric.

For Underarm Odor Treatment, Please Consult IC Clinic

If you are considering treatment for axillary osmidrosis, please feel free to consult IC Clinic.

IC Clinic offers a range of treatments — including sweat-reducing injections, miraDry, and the skin-flap surgical technique — with options tailored to the severity of your condition.

We can suggest flexible treatment approaches to match a variety of needs, such as “I want to see results quickly,” “I want surgery but would prefer to minimize scarring,” or “I want treatment that won’t interfere with my daily routine.”

To find the treatment approach that suits you best, we encourage you to make use of our free consultation.

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