How many sessions does it take for underarm laser hair removal?

Laser hair removal is an increasingly popular way to get rid of unwanted body hair. It works by targeting the hair follicle with pulses of highly concentrated light that damage the follicle and inhibit future hair growth. While laser hair removal can provide lasting results, it does require multiple treatments to fully remove hair from an area.

So how many laser hair removal sessions are needed to remove underarm hair? Typically, it takes 4-6 treatments spaced 4-6 weeks apart for optimal underarm hair removal. However, the exact number of sessions needed can vary based on factors like your hair color and thickness, the laser being used, and your body’s response to treatment.

Laser Hair Removal Basics

Before diving into the specifics on underarm laser hair removal, it helps to understand some basics about how laser technology removes hair.

There are three key principles that allow lasers to eliminate unwanted hair growth:

  • Selective photothermolysis – This is the ability of lasers to selectively target dark matter like hair follicles while leaving surrounding skin undamaged.
  • Chromophore targeting – Melanin in hair follicles absorbs laser energy. This allows the energy to damage structures responsible for hair growth.
  • Multiple treatments – Laser only impacts hair follicles in the active growth phase so multiple treatments are needed to target follicles in different stages.

These factors make laser very effective at preventing future hair growth. However, permanently removing every single hair follicle requires repeating treatments.

How Many Laser Sessions for Underarms?

Most laser specialists recommend between 4-6 treatments to fully remove underarm hair. Here is a more detailed look at what to expect during the multi-session process:

Sessions 1-3

During the first three laser hair removal sessions, patients will see a reduction in underarm hair growth of about 20-30% per treatment.

These initial sessions disable many of the active hair follicles. However, dormant follicles and straggler hairs may still produce some regrowth between treatments.

It typically takes 3 sessions to achieve around an 80% reduction in underarm hair. But results can vary based on your individual response.

Sessions 4-5

Additional treatments are usually needed to disable the remaining underarm hair follicles and achieve full clearance.

Sessions 4 and 5 produce less dramatic results compared to the first few treatments. Patients may see a 10-15% further reduction in hair growth with each additional laser session.

After 5 treatments, most achieve 95-98% underarm hair removal. At this point, remaining hairs are sparse, fine, and lighter in color.

Session 6

Some choose to do one final touch-up laser session 6-12 months after the initial set of treatments. This can help target any rare stubborn hairs and achieve full underarm hair removal.

After the 6th treatment, most find they can go years with smooth, stubble-free underarms before requiring any maintenance sessions.

Factors That Influence Number of Sessions

While 4-6 sessions is typical, the exact number of laser treatments needed depends on:

Hair Color

Lasers target melanin pigment in hair. So those with dark coarse hair often see the fastest response compared to people with blonde, red, or white hairs.

Light-colored hair may require more sessions for full underarm clearance.

Hair Density

People with dense underarm hair growth may need more treatments than those with fine sparse growth. Thick hair tends to be more stubborn to remove.


Hormonal factors can influence hair growth patterns. Those with high testosterone or polycystic ovary syndrome (PCOS) are often good candidates for extra sessions.

Laser Device

Modern lasers like the ND:YAG 1064nm, Diode 810nm, and Alexandrite 755nm are considered most effective options for underarm hair removal.

IPL devices are less powerful and may require more treatments for similar results.

Technician Skill

An experienced laser technician will tailor settings and treatment intervals for optimal results. Poor technique can lead to need for extra sessions.

Treatment Schedule

Ideally, laser hair removal treatments are spaced:

  • 4-6 weeks apart during the initial clearance phase (sessions 1-5)
  • 6-12 months apart for any touch-up sessions

This timing allows hair follicles to enter the active growth phase so they can be effectively targeted at the next appointment.

Treating more frequently than 4 weeks increases risk of side effects without much added benefit.

Who Is a Good Candidate for Laser Hair Removal?

The best candidates for laser hair removal have:

  • Dark coarse hair growth
  • Fair to olive skin tones
  • Realistic expectations about the multi-session process
  • No current skin conditions or medications that increase light sensitivity

Those with blonde, red, white or grey hair have low levels of melanin and won’t see significant results.

Tanned skin and darker complexions have higher risk of pigment changes or burns.

Laser works by heating the hair follicle so it cannot sustain growth long-term. It does not permanently destroy every single follicle after one session.

Preparing for Laser Hair Removal Treatments

To prep for optimal results during laser underarm sessions:

  • Shave the underarms 24-48 hours pre-treatment so hair length is ideal for laser targeting
  • Avoid sun exposure, tanning beds, spray tans to reduce risk of complications
  • Stop exfoliating and irritating underarms 2-3 days before
  • Avoid caffeine for 6 hours pre-treatment to minimizes discomfort
  • Take an anti-inflammatory like ibuprofen if prone to swelling

What to Expect During Underarm Laser Sessions

Here’s a quick rundown of what to expect when getting underarms treated:

  • The laser technician will clean and shave the underarm area.
  • The applicator handpiece is placed directly against the skin to deliver laser pulses.
  • You’ll feel a brief pricking or rubber band snapping sensation with each pulse.
  • Sessions take 15-20 minutes to treat both underarms.
  • 3-5 days after, shedding hairs may appear as treated follicles eject them.

Most describe the laser feeling as tolerable, like a hot pinch or zap. Your provider can supply numbing cream or adjust settings to maximize comfort.

Side Effects and Risks

Potential side effects include:

  • Redness and swelling for 24-48 hours
  • Tenderness
  • Temporary bruising or blistering (rare)
  • Hyperpigmentation or hypopigmentation
  • Paradoxical hair growth (rare)

Costs range from $150 to $350 per underarm session depending on your provider’s fees and your location.

While underarm laser hair removal is considered very safe when properly performed, minimizing risks depends on choosing an experienced technician.

Aftercare Tips

Be sure to care for your skin after laser sessions to aid healing and reduce irritation:

  • Use cool compresses to ease discomfort and swelling
  • Moisturize with aloe vera gel twice a day
  • Avoid hot showers, deodorant, antiperspirant for 24 hours
  • Wear loose clothing to minimize friction
  • Apply SPF 30+ sunscreen if going outside

Most side effects resolve within a few days.

Results Timeline

With a typical schedule of 4-6 sessions, patients can expect:

Treatment Number Expected Results
1 Up to 20% hair reduction
2 Up to 40% reduction
3 Up to 60% reduction
4 Up to 80% reduction
5 Up to 95% reduction
6 Up to 99% long-term reduction expected

With each session, patients notice less hair regrowth. But multiple treatments are needed to successfully disable all follicles and prevent re-growth.

How Long Does It Last?

With proper treatments, laser hair removal can provide permanent underarm hair reduction. Most patients enjoy years of bald underarms before requiring any touch-up sessions.

However, it’s important to note hair follicles can “wake up” over time. Your underarm hair growth may never return to pretreatment levels. But some maintenance sessions help sustain the smooth results.

Factors like hormones, genetics, and age will influence how long results last. Youth, menopause, and androgenetic alopecia can all impact hair regrowth.

Finding a Provider

When searching for a laser hair removal provider, the ideal candidate will have:

  • Dedicated laser training and several years of experience.
  • Modern FDA-cleared laser technology like ND:YAG, Diode, or Alexandrite lasers.
  • Strong attention to safety protocols and client comfort.
  • Onsite medical director and qualified technicians.
  • Customizable settings to tailor treatment for hair color and skin type.

Beware of “laser hair removal deals” at spas or salons with no dedicated physician oversight. Visit a reputable dermatology clinic with specific expertise in using lasers for permanent hair reduction.

The Takeaway

While a single laser session provides some hair reduction, most patients need 4-6 treatments for full underarm clearance. Spacing these treatments every 4-6 weeks allows time for hair to re-enter the growth cycle so it can be targeted again.

With multiple sessions, laser can provide years of smooth, stubble-free results. But periodic maintenance may be needed as hair follicles can eventually reactivate.

Achieving successful underarm hair removal relies on choosing an experienced laser technician, using appropriate settings for your skin type, managing expectations, and following all pre and post treatment care instructions.

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