Sure, Kim Kardashian West and Christie Brinkley have great genes, but they also have great dermatologists. Both have admitted to using laser treatments to keep their skin looking beautiful, but there are quite a few to choose from — what’s the difference between a Fraxel and an IPL, or Clear and Brilliant versus Trivantage?

YouTube reviews just weren’t giving us solid answers, so we turned to celebrity dermatologist Dr. Michele Green, who provided this cheat sheet of the most popular laser and pulsed light treatments.

Dr. Green says the first order of business is to be sure any laser or pulsed light treatment is performed by a well-trained physician — an untrained provider can cause serious, and even permanent damage.

“Get the procedure from a board-certified doctor with a knowledge of skin — only from physicians in the field,” she tells People. “Make sure this is what they’ve been doing for a long time, not that they just took a weekend class and you’re their first person. But when in the right hands, lasers are great for the skin.”

Fraxel Lasers

Kim Kardashian told Oprah she likes Fraxel laser treatments, and Dr. Green confirms they can help with sun damage, finelines and dullness.

“If you have a lot of sun damage, you might need twoFraxels, or you might need threeFraxels,” Dr. Green, who is based in New York City, says. A Fraxel, the laser’s brand name, treats a fraction of the skin, instead of the entire surface, and so lessens the recovery time to around five days.

“It’s two days where you’re red and two to three days where you’re peeling, but the results are dramatic,” she says. Removing a portion of the epithelium (the outer layer) of the skin encourages collagen production.

Dr. Green, who charges $1,500 per session, says the procedure doesn’t hurt because she applies a numbing cream 30 minutes beforehand. She also notes that patients should stay completely out of the sun after the procedure, so she doesn’t perform it at all in the summer months.

 

 Ari MichelsonAri Michelson

Clear and Brilliant

Christie Brinkley favors Clear and Brilliant laser treatments. “I grew up in Malibu, then my real job of modeling took me to beaches all over the world and under the sun. I really am aware of all the sun exposure I’ve had in my life and I’m interested in things that they can do to [reverse the sun’s effects],” the 62-year-old told People.

“Clear and Brilliant is like a mini Fraxel. It takes five sessions to get the effect of one Fraxel,” Dr. Green, who does not treat Brinkley, says. “But the good thing about it is that there’s no downtime.”

She explains that, like a Fraxel, the Clear and Brilliant laser makes microscopic holes in the skin through heat. “The skin has a microscopic injury, and so it regenerates and makes new collagen. But it’s very, very light with the Clear and Brilliant. You won’t even know that it’s happening apart from a minor sensation.”

Dr. Green also uses the numbing gel for the Clear and Brilliant treatment, so it’s painless;afterwardsthe skin is a bit red for about an hour. But you can get away with going to an event a couple of hoursafterwardsand you can definitely go to work the next day. The downside is the number of treatments needed, at $500 a pop.