Ultherapy vs. Thermage: Ultrasound and Radiofrequency

Ultherapy is a name associated with the Ulthera System, a focused-ultrasound device. Thermage FLX names a radiofrequency (RF) device. The cited U.S. Food and Drug Administration (FDA) records describe highly focused, low-energy ultrasound for the first system and RF energy with conductive cooling of the epidermis for the second. Their U.S. regulatory classifications differ. The records do not compare results, identify which approach suits an individual, or establish duration. U.S. classification does not define Korean authorization.

• The FDA device records identify focused ultrasound in one system and RF energy in the other.
• Neither an energy label nor a U.S. regulatory category establishes a result, ranking, individual suitability, or duration.
• RF is different from laser and intense pulsed light (IPL); the cited RF device description includes conductive cooling of the epidermis.
• The two U.S. classification names differ and do not state the scope of Korean authorization.
• Before treatment, discuss expected changes and complications. AAD says nonsurgical skin tightening is not right for people who are pregnant, have a skin infection, or take certain medicines; ASLMS identifies a pacemaker or implantable cardioverter-defibrillator as an RF contraindication. This is not a complete screening list.

This article compares the specific systems named in the FDA documents. It does not provide a direct clinical comparison of their outcomes or how long those outcomes last. Device names identify the records being discussed, not a product preference.

RF is different from laser and IPL

The American Society for Laser Medicine and Surgery (ASLMS) describes RF as a different form of energy from laser or intense pulsed light (IPL). The FDA’s Thermage FLX record also specifies conductive cooling of the epidermis during RF energy delivery. Neither description compares clinical effectiveness.

U.S. regulatory categories and Korean authorization

The FDA lists the Ulthera System as a “Focused Ultrasound Stimulator System for Aesthetic Use” and the Thermage FLX System as an “Electrosurgical Cutting and Coagulation Device and Accessories.” These U.S. classification names say nothing about Korean authorization or classification. A U.S. 510(k) clearance is a substantial-equivalence determination; it does not endorse one device over the other or provide a head-to-head clinical comparison.

Treatment conditions and regulatory intended use

The ASLMS review says RF session number and spacing may vary with the degree of skin aging and device characteristics. Separately, the FDA describes the focused-ultrasound system’s intended use as temporary changes in skin’s physical appearance. Neither statement compares how long results last.

There are also matters to check before treatment. Asan Medical Center advises understanding expected changes and possible complications when considering procedures for an aging face. The American Academy of Dermatology says nonsurgical skin tightening is not right for people who are pregnant, have a skin infection, or take certain medications. The ASLMS review identifies a pacemaker or implantable cardioverter-defibrillator as an important contraindication to RF treatment and says patients should be screened beforehand. These points come from different sources and are not an exhaustive list for every device or patient.

The ASLMS review describes temporary pain, redness, and swelling at RF treatment sites that usually resolve within 48 hours; tissue overheating can cause blisters, full-thickness burns, and eschar. These are class-level RF risks, not Thermage FLX-specific rates.

The same review describes ultrasound-site redness and swelling that usually resolve within 48 hours. Hives may last from two days to two months, and rare atrophic scarring has been reported. Improper transducer contact or excess gel may lead to blisters, erosions, or ulcers. The review also describes possible weakness of a motor nerve near the jaw, expected to resolve within two to six weeks. These are ultrasound class-level risks, not Ulthera System-specific rates.

References

1. U.S. Food and Drug Administration, “K243035 — Ulthera System 510(k) clearance and summary.” https://www.accessdata.fda.gov/cdrh_docs/pdf24/K243035.pdf
2. U.S. Food and Drug Administration, “K170758 — Thermage FLX System 510(k) clearance and summary.” https://www.accessdata.fda.gov/cdrh_docs/pdf17/K170758.pdf
3. American Society for Laser Medicine and Surgery, “Radiofrequency.” https://www.aslms.org/for-the-public/general-information/devices---radiofrequency
4. American Society for Laser Medicine and Surgery, “Minimally Invasive Procedural Treatments for Skin Laxity: A Review of the Literature.” https://web.archive.org/web/20240511101143/https://www.aslms.org/docs/default-source/for-professionals/mentorship-program/minimally-invasive-procedural-treatments-for-skin-laxity.pdf (archived copy).
5. Asan Medical Center, “노화된 얼굴 (Aging face)” (in Korean). https://www.amc.seoul.kr/asan/healthinfo/disease/diseaseDetail.do?contentId=31766
6. American Academy of Dermatology, “Many ways to firm sagging skin.” https://www.aad.org/public/cosmetic/younger-looking/firm-sagging-skin

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