TL;DR: Alexandrite laser (755 nm) is the gold standard for permanent hair reduction in Fitzpatrick I–IV skin types. High melanin affinity reaches more follicles per pulse than Diode or Nd:YAG, with faster results and fewer sessions in suitable candidates. Not safe in Fitzpatrick V–VI — use Nd:YAG 1064 nm instead.
How Alexandrite works
A chrysoberyl (alexandrite) crystal emits 755 nm light that is strongly absorbed by melanin. The pigmented hair shaft and follicular bulge heat up, destroying the germinal cells responsible for regrowth — permanent hair reduction, not "permanent removal" (some follicles always survive).
Melanin affinity ranking: 755 (Alex) > 810 (Diode) > 1064 (Nd:YAG). This is why Alex is more efficient on light skin but unsafe on dark skin (epidermal melanin absorbs as well).
Long-pulse vs Q-switch Alexandrite
- Long-pulse (ms range) — thermal effect, hair removal and vascular
- Q-switch (ns range) — photomechanical, pigmented lesions and tattoo
This guide focuses on long-pulse Alexandrite for hair removal.
Indications
- Face (upper lip, chin, sideburns)
- Underarms
- Bikini line
- Legs, arms
- Back, chest (especially male)
- Beard shaping (transgender care, PCOS)
Skin type suitability
| Fitzpatrick | Alexandrite |
|---|---|
| I (very fair) | Safe + efficient |
| II | Ideal |
| III | Ideal |
| IV | Safe with careful parameters + cooling |
| V | Not recommended — burn risk |
| VI | Contraindicated |
Dark skin → switch to Nd:YAG 1064.
Session planning
| Area | Average sessions | Interval |
|---|---|---|
| Face | 8–12 | 4–6 weeks |
| Underarms | 6–8 | 4–6 weeks |
| Bikini | 6–8 | 4–6 weeks |
| Legs | 6–8 | 6–8 weeks |
| Back / chest | 8–10 | 6–8 weeks |
Then annual maintenance: 1–2 sessions/year.
Procedure
- Consultation: Fitzpatrick assessment, hormonal status, medications
- Shave 24 h before; no waxing/epilation (root must be present)
- Antiseptic prep + protective eyewear
- Test patch (first session)
- Treatment with contact cooling or cryogen spray
- Cold pack after, SPF50+
Side effects
Expected: perifollicular erythema and edema 1–4 h, treated hairs shed in 5–10 days. Less common: mild crusting, transient hyper/hypopigmentation. Rare: burn, permanent pigment change, scarring, paradoxical hair stimulation (rare on facial vellus).
Contraindications
- Recent sunburn or fresh tan
- Fitzpatrick V–VI
- Active herpes (need antiviral prophylaxis)
- Pregnancy / breastfeeding
- Isotretinoin within 6 months
- Keloid tendency
- Active infection in treatment area
- Recent waxing/epilation (no root)
- Active vitiligo
Preparation and aftercare
Before (4–6 weeks): no waxing/epilation/electrolysis; shaving fine; sun avoidance + SPF50+; tell physician about photosensitizing meds. Day of: shaved, clean, no creams/makeup. After: 24 h cold compresses; 48 h no sauna/hot showers; 1 week no direct sun + SPF50+; 2 weeks no peeling/retinoid.
Alexandrite vs Diode vs Nd:YAG
| Feature | Alexandrite 755 | Diode 810 | Nd:YAG 1064 |
|---|---|---|---|
| Best skin | I–IV | I–V | I–VI (only safe in VI) |
| Melanin affinity | High | Moderate | Low |
| Penetration | Shallow-mid | Mid | Deep |
| Pain | Moderate | Moderate-low | Moderate-high |
| Speed | Fast | Fast | Slower |
| Dark-skin safety | Low | Moderate (cautious) | High |
FAQ
One session enough? No. Hair cycles require multiple sessions. White/blond hair? No — no target chromophore. Electrolysis instead. Recently tanned? Wait 4 weeks; strict SPF50+. Pregnant? No. Truly forever? Not "permanent removal" — "permanent reduction" with annual maintenance. Male patients? Yes — back, chest, shoulders, arms common; beard contouring popular. Paradoxical stimulation? Rare, mainly periorbital vellus in female patients; test patch + correct energy mitigates.
Our approach
- Skin type assessment + correct laser (Alex/Diode/Nd:YAG) per Fitzpatrick
- Test patch + written consent + before/after photos
- Contact-cooled handpiece — minimizes burn risk
- CE/FDA-approved device, certified operator
Conclusion
In the right skin type, Alexandrite is the most efficient hair-removal technology available. Correct patient selection, energy, cooling, and post-care discipline deliver high success with low complications.
Dr. Murat Toktamısoglu, MD, PhD — Ataşehir, Istanbul. WhatsApp: +90 533 356 2480. Last medical review: May 18, 2026.
