How Does Laser Hair Removal Work?

Key Takeaways

• Laser hair removal offers long-term hair reduction by targeting the hair follicle with concentrated light, resulting in slower regrowth over time.
• It's most effective on individuals with lighter skin and darker hair, but modern technologies are improving outcomes for a wider range of skin tones and hair types.
• Multiple sessions are usually needed to achieve optimal results, as hair grows in cycles and not all follicles are active at the same time.
• Proper pre- and post-treatment care—including avoiding sun exposure and following your technician’s advice—can enhance results and minimise potential side effects.

What is Laser Hair Removal?

Laser hair removal is a non-invasive procedure that reduces unwanted hair by using concentrated light energy to target hair follicles. The laser emits a specific wavelength that is absorbed by melanin (the pigment in hair), converting light into heat. This heat damages the follicle, slowing down or preventing future hair growth.

While the treatment significantly reduces hair regrowth, multiple sessions are typically needed for long-term results. 

Treatment Areas

Both women and men can achieve effective hair removal in various common areas where unwanted hair tends to grow. The following list highlights popular treatment areas for both genders:

• Legs
• Underarms
• Upper lip
• Chin
• Bikini line
• Back
• Chest

The Science Behind Laser Hair Removal

At the heart of this technique lies laser technology, which emits light at specific wavelengths that can be absorbed by target substances like melanin, the pigment found in hair. When the laser light is directed at the hair, the melanin absorbs the energy, converting it into heat. This heat damages the hair follicle, inhibiting its ability to regenerate hair. The treatment is most effective during the anagen (growth) phase of the hair cycle, when follicles are actively producing hair.

The success of the procedure depends on selecting the appropriate laser device. Different lasers are designed with varying wavelengths, which penetrate the skin to different depths and have varying affinities for melanin. 

For example, the Alexandrite laser, emitting light at 755 nm, is best suited for lighter skin tones, while the neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 1064 nm, works effectively on darker skin. 

The right choice of laser ensures that dermatologists can provide safe and effective treatment across a wide range of skin and hair types. As demand for these personalised treatments grows, the global laser hair removal market is projected to reach USD 1.58 billion by 2025, reflecting both technological advancements and increasing consumer interest in long-term hair reduction solutions.

Laseinfinity™ ‍Super Laser Hair Removal

At the Institute of Medical Physics, we offer a scientifically advanced approach with our exclusive Laseinfinity™ Super Laser Hair Removal treatment. This cutting-edge technology utilises six full-spectrum lasers, delivering optimal results for all skin types, hair colours, and body areas. This revolutionary approach maximises effectiveness while minimising any damage—even for the most stubborn hair.

What Does the Laser Hair Removal Process Involve?

The laser hair removal process involves a series of steps both before and after the treatment. Here’s what you can expect during the procedure:

1. Consultation

Before beginning any laser hair removal treatment, a thorough consultation is important to assess your skin type, hair colour, and overall suitability for the procedure. During this session, the dermatologist will review your medical history, answer any questions, and create a personalised treatment plan.

To enhance the precision of your treatment, we utilise our cutting-edge BHBR™ technology. This groundbreaking polymetabolic screening technique provides a detailed, clear picture of your unique biology, offering valuable insights into your hair growth patterns. With this information, we can optimise each session to ensure the most effective and personalised results for you.

2. Before Treatment

Before your first treatment session, avoid sun exposure and tanning for at least four to six weeks, as tanned skin increases the risk of side effects, and refrain from waxing or plucking for at least six weeks, as these methods can make the laser hair removal less effective. Shaving is acceptable, but avoid irritating skin products like retinoids or alpha-hydroxy acids, as they can increase sensitivity and the risk of irritation or redness following your laser treatment.

3. During Treatment

On the day of treatment, the targeted area will be thoroughly cleansed, and protective eyewear will be provided. The hair in the treatment area will be trimmed to a shorter length to improve the effectiveness of the procedure. The skin should be free of any abrasions, redness, or inflammation before the treatment begins.

The practitioner will use a handheld device to deliver laser pulses to the hair follicles. Each pulse lasts a fraction of a second. Most patients experience mild tingling or a warm sensation during the treatment, which is generally well-tolerated.

4. After Treatment

After the treatment, a soothing cream or probiotic spray is applied to the skin to promote healing and reduce any potential side effects. Multiple sessions are usually required to achieve optimal results, as laser hair removal only targets hair in the active growth phase. Dermatologists recommend spacing these sessions at intervals of three to eight weeks.

How Effective Is Laser Hair Removal?

While significant hair reduction may not be immediately visible after the first session, most individuals begin to notice changes after several treatments. Hair shedding typically occurs days to weeks following each session, providing a clearer picture of the treatment’s effectiveness over time.

Hair reduction generally becomes noticeable after the third or fourth session. Factors like hair type, skin tone, and the treatment area can influence the timeline, and individual results may vary. 

How Many Sessions Are Needed for Best Results?

On average, most individuals need between 6 and 8 sessions to achieve significant long-term hair reduction. However, the exact number of sessions may vary depending on several factors:

• Hair Type: Darker, coarser hair tends to respond more effectively to laser hair removal due to its higher melanin content, making it easier for the laser beams to target and destroy the hair follicle. Lighter, finer hair may require more sessions for noticeable results.
• Skin Tone: Individuals with dark hair and light skin generally see faster results, as the contrast between skin and hair colour allows the laser to target the melanin more effectively. 
• Treatment Area: Different areas of the body may require varying numbers of sessions. For instance, areas with denser hair growth, like the underarms or bikini line, may need more sessions than areas with finer hair, like the upper lip.
• Hair Growth Cycle: Since laser hair removal targets hair in the active growth phase (anagen), multiple sessions spaced 3 to 8 weeks apart are necessary to catch hair in this phase as it cycles through different stages of growth.
• Hormonal Influences: Hormonal imbalances or conditions such as polycystic ovary syndrome (PCOS), which affects 1 in 10 women in the UK, can lead to persistent hair growth, which may require additional sessions to achieve the desired results.

Over time, hair density and regrowth decrease, leading to smoother skin and fewer maintenance sessions. Patience and consistency are key, as the cumulative effects of each treatment session contribute to overall success.

Is Laser Hair Removal Permanent?

Laser hair removal is often marketed as a long-term solution for permanent hair reduction but it’s important to understand that it isn’t always permanent. While laser treatment significantly reduces hair growth, it doesn’t guarantee the complete and permanent removal of all hair.

Factors such as hormonal changes, genetics, and individual variations in how your body responds to the treatment can influence the results. For most people, laser hair removal provides a substantial reduction in hair density and regrowth, with many experiencing smooth, hair-free skin for months or even years after completing their sessions.

Risks and Side Effects of Laser Hair Removal

While laser hair removal is generally considered safe and effective there are some risks and side effects that potential patients should be aware of before undergoing treatment. Understanding these risks can help you make an informed decision and ensure a positive experience. Some of the potential side effects include:

Common Side Effects:

• Erythema (Redness): One of the most common side effects immediately following laser hair removal is redness of the treated area. This is temporary and subsides within a few hours to a day after treatment.
• Itching: Some people may experience mild itching at the site of treatment, which generally resolves on its own. This is typically a sign that the skin is reacting to the procedure, but it should not be a cause for concern if it's mild.

Severe Side Effects (Rare):

• Burns: If the laser is not calibrated properly or the procedure is not performed correctly, there is a risk of burns to the skin. Burns can lead to more serious long-term damage, including scarring. To avoid this, it's important to choose an experienced practitioner who uses high-quality equipment.
• Hyperpigmentation: Some individuals may experience darkening of the skin (hyperpigmentation) in the treated area. This is more common in people with darker skin tones, but it is usually temporary. In some cases, it can last for several months.
• Hypopigmentation: On the other hand, some people may experience lightening of the skin (hypopigmentation), particularly those with lighter skin. This condition can be more difficult to treat and may result in uneven skin tone.

To reduce the likelihood of these side effects, it's important to choose a reputable clinic or practitioner with a proven track record in performing laser hair removal. High-quality laser devices and proper calibration are crucial for ensuring safety. A skilled practitioner will consider the patient's skin type, hair colour, and medical history to determine the most appropriate laser settings. 

Before You Go

Achieving effective laser hair removal depends on various factors, including hair colour, skin tone, and the specific technology utilised. Traditionally, individuals with lighter skin and darker hair have experienced the best outcomes due to the contrast that allows lasers to target hair follicles more precisely. However, advancements in laser technology have broadened the range of treatable skin and hair types.​

At the Institute of Medical Physics, the Laseinfinity™ Super Laser Hair Removal system exemplifies these advancements. This system incorporates six specialised lasers, each tailored to address different skin tones and hair colours. This versatility enables the customisation of treatments to enhance both safety and efficacy.​

For personalised advice and to explore how Laseinfinity™ can be adapted to your specific needs, consider scheduling a consultation with the specialists at the Institute of Medical Physics.

Read More

• What to do after laser hair removal? 
• How old do you have to be to get laser hair removal treatment?
• How to prepare for laser hair removal? 
• How many sessions of laser hair removal?

About Us

The Institute of Medical Physics, founded by Dr. Emanuel Paleco, is at the forefront of Medical and Aesthetic Laser Science, with a flagship clinic in King's Cross and locations across North London and Essex. Our mission is to provide cutting-edge treatments rooted in science and guided by patient wellbeing.

Our exclusive Laseinfinity™ treatment represents the next generation of laser hair removal. By combining six advanced laser technologies into one comprehensive system, Laseinfinity™ allows for precise, safe, and effective treatment across all skin types and tones. Whether targeting fine facial hair or larger body areas, this system is designed to deliver lasting results with minimal discomfort.

At the Institute of Medical Physics, we are committed to innovation, safety, and personalised care—empowering you to feel confident in every treatment you choose.