Getting sucked into to a ShopNBC item can happen to the best of us, so I didn’t judge when a reader confessed to a trance-like state in front of Silk'N FaceFX Anti-Aging Heat & Light Therapy Tool (around $280). This is one of those at-home LED devices, although it claims to be different from the rest (eg Baby Quasar or Sirius Aurora) because it has something called “fractional light”. I wondered what this meant – if anything.

I’ve heard of fractional laser, but not fractional light. In fact, after reading around, I think that fractional light is a term that Silk'N FaceFX has made up. Fractional laser resurfacing, also known as fractional photothermolysis, targets areas of the skin that are precisely spaced out at a microscopic level and heats some skin zones while others are left undisturbed. Instead of emitting a solid beam, the laser puts out clusters of minuscule beams that punch invisible holes in the skin. An at home version of this would be the PaloVia. Meanwhile, Silk'N FaceFX  doesn’t function in this way at all. What this device does seem to use is LED (light emitting diodes that we are familiar with) and what it also alternately calls “dermal” or “thermal” heating.

Deep dermal heating has long been a salon treatment. Thermage is the one that most people are familiar with. But since it is painful and not especially effective, it has given way recently to newer treatments such as Pellevé. Thermage and Pellevé work in the same way by delivering gradual energy to the skin, causing heat to build up where the skin and fat layer come together. The increasing heat modifies the collagen bundles deep inside the skin. This part of the process is called denaturation. The denaturation of collagen fibers causes them to contract and, because they believe they are undergoing a trauma, they start stimulating the growth of new collagen. The advance that Pellevé has made over Thermage is that the denaturation takes place at 41°C (rather than 65 degrees with Thermage).

And this is where the debate over Silk'N FaceFX really heats up. As I mentioned, Thermage’s 65 degrees has a reputation for being painful. I’ve had Pellevé in the hands of a trained professional and 41°C, I can tell you, is hot and it is essential that the practitioner keeps the device moving around the skin at all times to prevent burning. I personally wouldn’t dream of trying this out at home. So my guess was that Silk'N FaceFX, given that it has FDA approval, probably doesn’t get up to 41°C.

My hunch was right. The specifications of the Silk'N FaceFX state that the operating temperature is 15°C to 35°C. I also found a safety study during which the device cut off when the skin surface temperature reached 41°C. It is unlikely then that denaturation is taking place with the Silk'N FaceFX. In other words, it probably doesn’t work.

The reviews are a mixed bag, but there are an awful lot of them that are disappointed and saw no results after a month of using Silk'N FaceFX three times a week. I’ll think I’ll stick with my Ultra Renew LED/ultrasonic device.