Gua sha has had a second life on social media as a smooth stone for the face, but it started out as a much firmer body technique in Chinese medicine. I sometimes use it alongside acupuncture. Here's what it is, where it comes from, why it leaves marks, and what one well-known study measured.
What is gua sha?
The name joins gua, the scraping of the skin, with sha, the marks that appear afterwards. The technique itself is a series of repeated, one-direction press-strokes over lubricated skin with a smooth-edged instrument, carried on until small blemishes appear.
A 2016 paper in the journal PeerJ pictures a smooth-edged tool made of bull-horn, roughly the size and shape of a credit card. Oil or balm on the skin lets the tool glide rather than drag.
Where does it come from?
Skin-based techniques such as gua sha and cupping were developed in China around 2,000 years ago.
In traditional Chinese medical theory, gua sha is described as a way to help clear sha, thought of as something the body can't clear by itself. That's a traditional explanation rather than a proven mechanism, and it's best understood that way.
What does it feel like?
Usually a firm, scraping pressure, a little like a deep massage with an edge. Some areas feel tender while it's happening. I check in with you as I go, and the pressure can be eased at any time. Many people find it relaxing once they get used to the sensation.
Why do the marks appear?
The red or purple dots and patches are what give gua sha its name. Sha refers to petechiae, tiny spots that appear when small blood vessels near the surface leak a little blood into the skin. Where the spots merge they can look more like a flat bruise.
The marks usually fade and clear completely within 2 to 5 days. If you're having a medical examination in the next few days, mention that you've had gua sha so nobody mistakes the marks for something else.
What did the research measure?
One of the best-known studies is a small pilot published in the journal Explore in 2007 by Arya Nielsen and colleagues, including Ted Kaptchuk. They used laser Doppler imaging, which measures blood flow in the surface of the skin, on 11 healthy volunteers before and after gua sha on the back.
They reported a roughly fourfold increase in surface microcirculation at the treated area for the first 7.5 minutes, and an increase could still be measured throughout the 25-minute observation period. Women responded more strongly than men, and no adverse reactions were recorded. The authors suggested that this change in circulation might play a part in the effects people report.
Keep that in proportion, though. It was a pilot study of 11 people with no control group, its main measure was blood flow in the skin of healthy volunteers, and one small study can't tell us what gua sha does for any condition. I don't offer gua sha as a treatment for anything specific. It's simply one of the hands-on techniques I may use as part of a session.
A few practical notes
- Tell me about any medicines you take, especially blood thinners, and about any bleeding or skin conditions.
- Gua sha isn't a substitute for medical care, so keep up anything your GP has advised.
If you'd like to see how gua sha, cupping and moxa fit around acupuncture at my clinic, take a look at what happens at your first visit.