Hair Removal Lasers: Comparing Diode and Alexandrite Lasers (2024)

How Do You Find the Best Laser for Your Hair Removal?

Diode vs. Alexandrite Lasers – Which Delivers the Best Laser Hair Removal Results

What’s the bottom line for choosing the best laser hair removal machine – diode or Alexandrite?

Here it is.

No fluff, just the best information from multiple studies done that will save you money.

Caution – results are also heavily dependent on operator experience. This experience includes choosing the optimal setting on the laser that is used.

Let’s eliminate that factor and assume the laser operators are equal.

Disclaimer – you can’t.

So, it’s much more important to choose your laser hair removal operator and center carefully.

You must also be aware that some laser places switch you from operator to operator with each treatment.

With these types of places, it all depends who is available the minute that you walk in.

Therefore, experience counts a lot in this debate.

Realistically it is more important than the choice of diode vs. Alexandrite laser.

Dr. Roy Geronemus is a laser expert in New York owns more than 50 lasers.

He prefers the Alexandrite laser for hair removal but also uses the diode and Nd:Yag lasers on patients with darker skin to prevent burns and complications.

The first two types of lasers (diode and Alexandrite) have produced similar results in early trials comparing the two types of lasers.

Nd:Yag lasers are the only option with dark skin and not as effective with light skin.

Dermatologic surgery reports that results with diode and alexandrite were essentially the same.

Other studies of comparing these two types of lasers after four treatment sessions confirmed these results.

No studies have extended the follow-up times beyond two years and only three controlled trials had follow-up times beyond one year.

What is the Difference Between Diode and Alexandrite Lasers for Hair Removal?

Although Diode can treat patients with slightly darker skin tones, Alexandrite lasers tend to shine for lighter skinned individuals.

Let’s start with the pain of having laser hair removal.

Pain sensitivities vary widely.

It has been reported in Cosmetic Surgery Times that the LightSheer (diode laser) hurts more than the GentleLASE (Alexandrite laser) on a per laser pulse basis.

More pain was also reported with the new diode lasers by Grunewald (2014) but otherwise efficacy was similar to Alexandrite lasers.

Having said that, let’s compare the diode vs. Alexandrite laser hair removal studies.

Diode lasers use a longer wavelength (usually around 810nm).

That results in a deeper penetration of the skin.

The longer wavelengths avoid skin damage superficially near the skin’s surface in darker skin patients.

Diode lasers also perform slightly better on coarse hair like pubic hair.

On the other hand, Alexandrite lasers have a shorter wavelength.

That is good for lighter skin types (people who burn easily when tanning).

In our laser center, the Alexandrite lasers (which have a shorter wavelength around 755 nm) excel with whiter or light skin color.

What about Problems or Complications of Diode and Alexandrite Lasers?

A 2006 review article in the journal “Lasers in Medical Science” compared both Alexandrite and diode lasers.

In this study, diode lasers were found to cause problems in 28.9% compared to 9.5% with the Alexandrite lasers. These side effects and complications resolved within six months.

Side effects were observed with all laser sources but also more frequently with Diode in another study.

In an early 2001 study, the two lasers were compared to see which produced the best long-term results.

Twelve-month results with the alexandrite and diode lasers achieved 85% versus 84% hair reduction.

For most patients, four treatment sessions got excellent results of hair removal in the 90% range after 12 months.

The higher power with relatively larger laser head (12 mm round for the 755 nm alexandrite and 9 mm for the 800 nm diode) resulted in these excellent results.

Another study in 2004 in Dermatologic Surgery Dermatologic Surgery Journal in 2004 compared 3 types of lasers.

The results were a greater reduction in hair with the Alexandrite (65.6%) vs. 46.9% with the Diode lasers. This was not statistically significant as a difference.

Nd:/YAG lasers were not as effective 42.4% but were better for the darkest skin in reducing burns and heat related skin complications.

One of the leading laser experts, Dr. Tina Alster, in 2001 confirmed the equal effectiveness of Alexandrite and Diode lasers.

Disadvantages with Diode Lasers

The diode wavelength works on the same category of skin types and hairs as the Alexandrite but may not be as effective for lighter colored hairs.

It really depends on skin type as to how far the power or intensity of the laser can be pushed to treat lighter hair colors.

A laser operator can get away (read – it is safer) with treating slightly darker skin colors with a diode laser.

The darkest skin colors are best treated with an Nd:YAG lasers which have a wavelength of 1064nm.

Diode lasers have a smaller diameter beam – due to their smaller application area (surface area of the probe the contacts the skin).

Early diode lasers had a surface area of 9mm square. Those lasers can take twice as long to treat the same area as compared to the time taken when using a typical Alexandrite laser machine.

Lightsheer is a brand of diode laser sold by the company, Lumenis.

It offers a huge spot size of 22×35 mm which allows for a deeper penetration (good) and the ability to treat large areas like the back or legs much more quickly.

These lasers suck the skin to provide optimum contact with the cold head. The smaller 9×9 mm head is also available.

For cooling with diode lasers, a cooling contact tip is used. This is not as effective pain wise as the Cryogen gas is sprayed as a burst just before the laser pulse with Alexandrite lasers.

Practically, it is more difficult to provide consistent contact with the skin with a Diode laser as opposed to the increased fine control of the zap or small spray of laser light with the Alexandrite lasers.

Subtherapeutic low power of a diode laser may induce more hair growth called as paradoxical hypertrichosis.

That is how laser combs theoretically cause hair growth in men and women who suffer from hair loss.

This is also the mechanism that low-level laser therapy (also called a soft laser, cold laser or LLLT) is used to increase cell division in the hair follicle causing new hair to grow.

American Laser Skincare, the largest laser hair removal chain in the country, used the Soprano diode laser and went bankrupt in 2014.

Disadvantage of Alexandrite Lasers

The main controversy or concern is the Cryogen cooling of the Candela brand of Alexandrite laser hair removal machines.

The Cryogen comes in liquid form at very low temperatures. (-238 degrees Fahrenheit). The gas released from the cryogenic liquids remains very cold.

Oxygen deficiency, frostbite, explosion and flammability are hazards of cryogen in a poorly ventilated room. Problems can also occur with the Cryogen’s delivery system.

With the Cynosure brand of laser machines, a different type of cooling system is used.

It is called a Zimmer cooler. A Zimmer is a separate machine from the actual laser and costs $3000 for a refurbished model and up to $9,000 for the new Cryo 6.

It blows cold air contiguously on the skin like through a nozzle like a vacuum cleaner (in reverse).

Cryogen is more effective than a Zimmer machine in cooling the skin and providing a more comfortable experience for the patient during laser hair removal.

Candela brand of Alexandrite has a larger spot size of 18mm as opposed to Cynosure brand of Alexandrite with their 15 mm spot size.

The 69% larger spot size means for large areas, it is much faster.

The Bottom Line – Which Laser Should You Choose?

Alexandrite and Diode lasers are equally effective in reducing hair.

Two studies compared the Alexandrite vs. Diode lasers and similar treatment outcomes were obtained after repetitive treatments at six and twelve months after the treatments.

Alexandrite lasers with the Cryogen cooling system are the least painful.

Diode lasers can be used in slightly darker skin but Nd:Yag lasers are used in the darkest skin and are less effective.

Intense pulsed light machines can remove hair but are inferior to true lasers and have a steep learning curve.

IPL is actually just a flash lamp and is not an actual laser.

IPL machines are viewed by experts as equivalent to long term waxing.

If you live in Pittsburgh around the Bethel Park and South Hills Village area, you want the best laser hair removal machine that will deliver the best results with the least amount of discomfort.

See and feel the difference with the built-in cryogen cooling spray.

Call us at 724-969-0600 for a free demo with our state-of-the-art Alexandrite laser.