Is Laser Hair Removal Really Permanent? Evidence-Based Analysis
- Virginija M.
- Jun 19
- 6 min read
Summary
The Science Behind Hair Growth
Defining "Permanent": What the Research Actually Says
Factors That Influence Permanency
The Reality: What Clients Can Expect
Maximising Your Results: Evidence-Based Recommendations
The Technology Factor: Why Your Choice of Clinic Matters
Conclusion: What Does “Permanent” Mean for You?
About Cells Aesthetics
Clients often ask us: “Is laser hair removal really permanent?”
It’s a good question — and one that deserves a clear, honest answer.
At Cells Aesthetics we believe in evidence-based treatments and realistic expectations. In this article, we break down what the science actually says about laser hair removal, how “permanent” it really is, and what results you can expect based on clinical research and our hands-on experience.
The Science Behind Hair Growth
To understand if laser hair removal can deliver permanent results, we first need to grasp how hair grows.
Understanding the Hair Cycle
Hair growth occurs in three phases:
Anagen (growth phase): Hair actively grows. Crucial for laser targeting.
Catagen (transition phase): Hair growth slows, follicle shrinks.
Telogen (resting phase): Hair rests, eventually falling out.
Why does this matter? Laser treatments are only effective on hairs in the anagen (active growth) phase—which typically includes just 20–30% of your hair at any given time. That’s why multiple sessions are needed. Each treatment targets a different subset of active follicles, leading to gradual, cumulative reduction. The graph below illustrates how results build over a full treatment course.
As you can see, hair removal is progressive, not immediate—which is why a full course of treatments is essential for optimal results.
Melanin and Light Absorption
Lasers work on the principle of selective photothermolysis, where laser energy is absorbed by melanin—the pigment in hair. The absorbed energy converts to heat, destroying or damaging the follicle without harming surrounding skin.
Clinical data consistently shows that darker, coarser hairs respond better due to higher melanin concentrations, while lighter hairs (blonde, red, grey) are often less responsive, though technology continues to evolve to address these challenges.
Defining "Permanent": What the Research Actually Says
The word “permanent” can be misleading when it comes to laser hair removal. It's important to understand what it means from a regulatory and scientific standpoint—especially within the UK.
MHRA Classifications: What “Permanent” Really Means
In the UK, laser hair removal devices are regulated by the MHRA (Medicines and Healthcare products Regulatory Agency). This government body ensures all medical and aesthetic equipment is safe, effective, and meets high standards.
The MHRA classifies laser systems as medical or cosmetic devices, depending on how they’re used. It also makes a clear distinction between:
Permanent hair reduction: A long-term, stable decrease in the number of regrowing hairs after a treatment regimen. (MHRA-approved claim).
Permanent hair removal: A much higher standard implying the complete, lifelong elimination of hair (not guaranteed or approved).
In essence, if a clinic or device promises 100% “permanent hair removal,” that’s not only scientifically unlikely—it’s also not MHRA-compliant.
What the Research Supports
Numerous peer-reviewed clinical studies have shown that patients experience an average of 70–90% long-term hair reduction after completing a full series of professional laser hair removal treatments. However, due to factors like hair cycle biology, hormonal changes, and genetics, some regrowth is possible over time.
The Reality: What Clients Can Expect
Laser hair removal consistently delivers significant, long-term hair reduction — but not all areas of the body respond in the same way. That’s because different regions have different hair densities, growth cycles, and hormone sensitivities.
Underarms/Bikini: Often achieve around 90% reduction. These areas typically respond best to laser hair removal because the hair tends to be coarser, darker, and more pigment-rich, making it easier for the laser to target effectively. Additionally, underarm and bikini hair often grows in well-defined cycles, allowing treatments to align more accurately with the anagen phase.
Legs and Arms: Approximately 70-85% reduction. Hair in these areas is often less coarse than bikini or underarm hair, but still contains enough melanin for good laser absorption. However, because leg and arm hair may grow more diffusely and with a longer cycle, it can take more sessions or slightly longer intervals to achieve optimal reduction.
Facial hair: Typically 60-80% due to hormonal influences. Facial hair, especially on the chin and upper lip, is often influenced by androgens (male hormones), even in women. This hormonal stimulation means new follicles can become active over time, which makes the area more prone to regrowth and typically requires ongoing maintenance sessions for sustained results.
Factors That Influence Permanency
Biological Variables
Hormonal changes: Hormonal conditions such as PCOS, menopause, and pregnancy can significantly influence hair growth patterns, often requiring a more tailored and long-term treatment plan.
For example, individuals with PCOS may experience regrowth in hormone-sensitive areas despite multiple sessions. In such cases, ongoing maintenance treatments or combination approaches (e.g., medical management alongside laser therapy) may be recommended.
Age and genetics: As we age, hormonal profiles shift, and some people may develop new hair growth patterns. Genetics also play a role in how thick, dark, or resilient your hair is, which can affect how well it responds to treatment.
Medical conditions: Disorders like hypothyroidism or certain autoimmune diseases can disrupt hair growth cycles. Additionally, treatments such as corticosteroids or androgen-based medications can reactivate dormant follicles.
Treatment Variables
Number of sessions: Most individuals require 6–10 sessions to achieve significant reduction because not all hair follicles are in the growth (anagen) phase at the same time. Skipping or under-treating can leave a significant percentage of follicles unaffected.
Session spacing: Spacing treatments 4–8 weeks apart aligns with the hair’s natural cycle, allowing new follicles to enter the anagen phase and be effectively treated. Too-close scheduling can reduce efficiency, while too much time between sessions allows regrowth.
Laser technology: Devices like the Soprano Titanium use advanced multi-wavelength technology to target a broader range of hair types and skin tones. Outdated or single-wavelength systems may yield slower results or increase the risk of side effects.
Practitioner expertise: A qualified aesthetician knows how to tailor settings to your skin type, hair density, and sensitivity—improving both safety and results. Inexperienced hands may under-treat or over-treat, compromising outcomes.
Lifestyle and Environmental Factors
Medication effects: Certain drugs, including some antidepressants, hormonal contraceptives, and anabolic steroids, can stimulate unwanted hair growth. This means even after successful laser treatment, new growth may emerge if medication changes.
Sun exposure: UV exposure before or after laser sessions can sensitise the skin, increasing the risk of burns, hyperpigmentation, or reduced treatment effectiveness. This is why laser hair removal is often recommended in autumn or winter.
Skincare routines: Using retinoids, strong acids, or exfoliants immediately before or after treatment can irritate the skin or delay healing. A simple, calming post-treatment skincare routine is vital to avoid complications and maximise results.
Maximising Your Results: Evidence-Based Recommendations
Here’s how to achieve and maintain optimal laser hair removal outcomes:
Pre-treatment Preparation
Avoid sun exposure: Minimises skin sensitivity and hyperpigmentation risk.
Shave (don’t wax): Ensures follicles remain intact for targeting.
Skincare: Hydrate and soothe skin to enhance treatment comfort.
During Treatment
Pain management: Choose treatments with built-in cooling technology.
Consistency: Maintain scheduled appointments for maximum results.
Track Progress: Document hair reduction objectively for clarity.
Post-treatment Care
Aftercare: Use soothing gels and SPF protection consistently.
Monitor results: Watch for reduced hair density and slower regrowth.
Seek professional advice: Any unusual reactions should prompt professional consultation.
The Technology Factor: Why Your Choice of Clinic Matters
Advanced Laser Systems
Not all laser devices deliver the same results. Older systems like IPL or single-wavelength lasers often underperform—especially on darker skin or finer hair—resulting in slower progress or increased risk of side effects.
Newer systems feature:
Multiple wavelengths for targeting hair at different depths
Integrated cooling for comfort and safety
In-motion technology for even, efficient coverage
These innovations make treatments faster, safer, and more effective across a wider range of skin tones and hair types.
Studies show that modern diode lasers outperform older devices in long-term hair reduction and patient satisfaction. Many are MHRA-certified, ensuring they meet UK standards for safety and efficacy.
Technology directly impacts your results. Choosing a provider with advanced systems ensures more effective, longer-lasting hair reduction with fewer risks.
Conclusion: What Does “Permanent” Mean for You?
Laser hair removal can provide remarkable permanent hair reduction, typically between 70-90%. True permanence is rare but lasting reduction and easier maintenance is achievable.
The key to success lies in choosing the right clinic, skilled practitioners, and advanced technology. When you invest in professional laser hair removal, you're investing in long-term convenience, confidence, and freedom from constant hair maintenance.
For Brighton residents seeking permanent laser hair removal, the combination of advanced technology, expert practitioners, and realistic expectations creates the foundation for excellent results.
About Cells Aesthetics
At Cells Aesthetics, we’re committed to transparency, realistic expectations, and evidence-based care. We invite you to visit us in Brighton & Hove for a personalised consultation, where we will discuss your specific needs and the scientifically supported path to achieving them.
We offer:
Evidence-based aesthetic solutions.
Personalised, holistic skincare approach.
Professional, accredited expertise in Soprano Titanium laser technology.
Convenient location serving Brighton, Hove, and surrounding areas.
Book your free consultation to experience Brighton’s best in aesthetic care.