Alexandrite vs Nd:YAG: How Skin Tone Should Drive Your Laser Hair Removal Choice in Beverly Hills

Walk into almost any laser practice in Beverly Hills and you will encounter two names on the treatment menu for hair removal: the Alexandrite laser at 755 nanometers and the Nd:YAG laser at 1064 nanometers. Both are legitimate, well studied devices. But they are not interchangeable, and the single most important variable in choosing between them is the amount of melanin in your skin.

The mechanism, in plain terms. Laser hair removal works through a principle called selective photothermolysis. The laser emits a specific wavelength of light that is preferentially absorbed by a target chromophore, in this case the melanin concentrated in the hair follicle. The absorbed light converts to heat, and that heat damages the follicle structures responsible for regrowth, particularly the bulge and bulb regions. The pulse must be short enough to confine heat to the follicle but long enough to cook it thoroughly, which is why practitioners adjust pulse duration alongside energy settings. For an independent overview, see Laser hair removal: overview and what to expect.

Why wavelength matters. Melanin absorbs light most strongly at shorter wavelengths. The 755 nm Alexandrite wavelength is absorbed by melanin roughly two to three times more efficiently than 1064 nm light. That makes Alexandrite highly effective on fine or lighter brown hair, because even modest melanin content in the follicle soaks up enough energy to matter. The tradeoff is that melanin in the epidermis, the outermost skin layer, absorbs that same light. In deeply pigmented skin, an Alexandrite pulse can heat the surface enough to cause blistering, hyperpigmentation, or hypopigmentation.

The Nd:YAG at 1064 nm sits at the other end of the practical spectrum. Melanin absorbs it weakly, which means the epidermis in darker skin tones is largely spared. The light also penetrates deeper into the dermis, reaching follicles that sit four to five millimeters below the surface. The cost of that safety margin is efficiency: because follicular melanin also absorbs 1064 nm light less avidly, higher fluences are typically needed, treatments can feel more uncomfortable, and results on fine or light hair are noticeably weaker.

Matching device to Fitzpatrick type. Clinicians classify skin using the Fitzpatrick scale, which runs from Type I, very fair skin that always burns, to Type VI, deeply pigmented skin that never burns. As a general clinical pattern, Alexandrite lasers perform well and safely on Types I to III. Type IV sits in a gray zone where an experienced operator may use either device with conservative settings and test spots. Types V and VI are almost universally treated with Nd:YAG, and peer reviewed dermatology literature consistently supports 1064 nm as the standard of care for darker skin.

This matters in a city as demographically diverse as Los Angeles. A practice that owns only an Alexandrite platform has an incentive to treat everyone with it. A practice equipped with both, or with a dual wavelength system, can match physics to the patient rather than the other way around.

What about diode lasers? Many offices also run 800 to 810 nm diode devices, which occupy a middle position. They are versatile across Types I to IV and, with long pulse durations and aggressive cooling, are sometimes used on Type V. They do not change the underlying logic: shorter wavelength favors efficacy, longer wavelength favors epidermal safety.

Tanned skin is a temporary skin type change. A point that surprises many patients: a recent tan, whether from sun or a spray product containing DHA in some cases, effectively shifts your skin toward a darker Fitzpatrick behavior for laser purposes. Reputable practices ask you to avoid significant sun exposure for two to four weeks before treatment. If a provider is willing to fire an Alexandrite at visibly tanned skin without adjusting the plan, that is a red flag.

Cooling is not a luxury. All modern platforms pair the laser with epidermal cooling, whether cryogen spray, a chilled sapphire contact tip, or forced cold air. Cooling protects the surface while the deeper follicle heats, and it is a core part of the safety equation rather than a comfort add-on.

Reasonable expectations. No wavelength delivers permanent, total hair removal in one visit. Follicles cycle through growth phases, and only follicles in the active anagen phase respond well. Most patients need six to eight sessions spaced four to eight weeks apart, with occasional maintenance afterward. White, gray, and true blonde hair lacks the melanin target entirely, and no mainstream laser treats it effectively regardless of what a consultation promises.

Questions to ask at consultation. Which wavelengths does the practice operate, and why is a given one recommended for your skin and hair combination? Will a test spot be performed? Who actually fires the laser, and what is their training? How is cooling delivered? Clear, specific answers to those four questions tell you more about a practice than any before and after gallery.

Related reading: Alexandrite vs. Nd:YAG: How Wavelength Decides Who Can Safely Get Laser Hair Removal.