The In-Office Treatment That Builds Long-Lasting Collagen

Vogue

05-07-2025

I've always followed the skincare holy trinity: good nutrition, adequate sleep, and lots of SPF. But when I turned 35, I started to think about something that had never crossed my mind before: skin laxity. I found myself examining my face in the mirror more closely. Is that a new wrinkle? Am I getting jowls? Suddenly, my daily collagen drinks didn't seem like enough.
Last week, I finally decided to undergo my first in-office treatment. No, I didn't get Botox or fillers. Instead, I went with something non-invasive that promised to address my biggest concern: collagen loss.
My treatment of choice? Thermage FLX, which is FDA-approved and marketed as one of the most powerful in-office radiofrequency treatments on the market. According to one recent scientific analysis that looked at 52 surveys among dermatologists, Thermage FLX was considered 57.4% more effective than older Thermage devices. I figured that if it was good enough for Jennifer Aniston and Gwyneth Paltrow, it was good enough for me.
What is Thermage FLX?
Thermage FLX is a non-invasive monopolar radiofrequency treatment that 'ensures stimulation of endogenous collagen with just one treatment,' says Dr. Óscar Suárez, founder and medical director of Barcelona's MD Cliniques. He says it's so effective that a once-a-year treatment is enough for most people.
But what exactly makes Thermage FLX so effective? 'It's specially designed to reverse skin flaccidity and improve wrinkles and expression lines,' explains Dr. Maria Dolores Antón, an aesthetic doctor and the medical director of Antón Clinic in Valencia, Spain. 'It tightens and firms the skin through an extremely precise delivery of energy. The device can be used to treat all areas that show the effects of flaccidity: cheeks, eyelids, jawline, bags, buttocks, arms, abdomen, knees, and thighs.'
How does Thermage FLX work?
Basically, Thermage FLX emits low-frequency electromagnetic waves to generate heat below the surface of the skin. 'The heat penetrates deep into the skin to stimulate the production of collagen, which is responsible for tissue tightening, rejuvenation, and improved elasticity,' explains board certified dermatologist Dr. Tanya Kormeili, a clinical instructor at UCLA. 'Because collagen and elastin are essential for skin firmness and youthfulness, the more you build the more youthful your skin can be in theory,' she says.
Thermage FLX heats the deepest layer of the skin to around 140°F to stimulate the fibroblast to increase collagen production. 'Thermage FLX acts directly on the deep dermis in a very specific way: It causes shrinkage of old collagen and gives a message to the fibroblast to generate new, high-quality collagen,' Anton says.