A laser fires one wavelength. BBL does not — it fires a broad spread of them from a xenon flashlamp, then uses a filter to block everything below a chosen cutoff. That is what makes it intense pulsed light rather than a laser, and it is a real distinction, not a technicality. A laser is precise; IPL is a floodlight with a gate on it.
Different filters change what the light can find. A 515 or 560 nanometer filter lets through wavelengths that melanin absorbs well, so it targets brown spots. A 560 or 590 nanometer filter is used for oxyhemoglobin in blood vessels, so it targets redness. The energy absorbed becomes heat: pigment clusters get damaged and rise to the surface as fine dark specks that flake off, and small vessels are heated until they collapse and get reabsorbed.
Sciton's BBL adds a cooled sapphire crystal in the handpiece that chills the surface while the pulse fires, which lets the operator use more energy with less risk of a surface burn. BBL HERO ("High Energy Rapid Output") is a faster, higher-power version aimed at treating large body areas — arms, chest, back — in a reasonable time.
The core limitation is unchanged by any of this. Because the light covers a wide band, it cannot distinguish the melanin in a sun spot from the melanin spread evenly through darker skin. On light skin there is enough contrast for the spots to absorb more than the background. On deep skin tones there is not, and the energy goes into the whole treated area.
Ask what filter and what settings will be used, and ask for a test patch if your skin is anything other than clearly fair. A test on the jawline or behind the ear, read a week later, is worth the extra visit.
Say if you have ever had melasma, even if it is quiet right now. That changes the plan.
Say if you get cold sores — antivirals are started the day before for facial treatments.
List your medications. Doxycycline, some diuretics and other drugs make skin light-sensitive.
No sun on the treatment area, no sunbeds, no self-tanner. A tan is the single most common reason a BBL session goes wrong, and the clinic should postpone you if you turn up tanned.
Stop retinoids and exfoliating acids on the area.
Do not wax, thread or epilate the area — hair follicles absorb the light too.
Come with bare, clean skin. No makeup, sunscreen or moisturizer.
Eat first. It is not painful, but people who arrive faint do worse with heat and light.
Your skin is cleaned and you put on opaque eye shields — light this bright is a genuine hazard to the retina, so they go over your eyes completely and you will not be able to see during the treatment.
A layer of cool gel is applied on most protocols.
The handpiece is pressed flat against the skin and fired, then moved along in overlapping stamps. The cooled sapphire tip feels cold against the skin between pulses.
Each pulse is a flash of light and a snap of heat, most often described as an elastic band flicked against sunburn. It is brief. Around the nose, the upper lip and over bony areas it stings more.
A full face takes about 15 to 30 minutes. Adding the neck, chest or hands adds time. BBL HERO on a large body area is faster per unit of skin than standard BBL.
You come out flushed and warm, as if you had spent an afternoon outside. Brown spots often look slightly darker before you leave the room.
Rules throughout: no hot showers, saunas, hot yoga or heavy exercise for 48 hours; no retinoids or acids for about five days; keep moisturized; and daily sunscreen on treated skin, without exception, throughout the course and for a month after. Sun during a BBL course is how people end up more pigmented than when they started.
There are home IPL devices, but they are not BBL and they are not comparable. They fire at a small fraction of the energy, have crude or no filtering, and no contact cooling of the kind BBL uses. Most are sold for hair removal rather than pigment or redness, and the ones marketed for "skin rejuvenation" produce very little.
They also carry the same skin tone problem in a worse form. Most home IPL devices have a built-in sensor that refuses to fire on dark skin — which is honest of them, and also means they are useless for a large share of the people who buy them. Using one on deep skin tones, or overriding the sensor, causes burns and pale patches.
If you want at-home progress on the same problems: for brown spots, daily sunscreen, a retinoid, and a lightener such as azelaic acid, tranexamic acid or alpha arbutin. For redness, azelaic acid and prescription treatments such as metronidazole or Soolantra do more for rosacea than any home light device.