The Q-Collar is a wearable device that sits around the neck and applies light pressure to the jugular veins, slightly increasing the volume of blood inside the skull. The idea is that this extra blood fills the space around the brain more tightly, reducing the brain’s ability to slosh around inside the skull during impacts. It’s FDA-cleared as a Class II medical device for athletes aged 13 and older to help protect against the cumulative effects of repetitive sub-concussive head impacts during sports.
How the Q-Collar Works
The collar is a U-shaped device that rests on the neck and presses gently on the jugular veins, the main vessels that drain blood from the head. This compression doesn’t block blood flow. Instead, it slows the outflow just enough to keep a slightly larger volume of blood inside the cranial space at any given moment. That extra blood acts like packing material, reducing the gap between the brain and the skull. With less room to move, the brain experiences less of what researchers call “slosh,” the internal movement that occurs when the head absorbs a hit.
The design was inspired by the woodpecker. Woodpeckers slam their beaks into trees at high speed repeatedly without brain injury, and one reason is that their skulls contain very little cerebrospinal fluid. Their brains are essentially packed tight against the skull wall, leaving almost no room for the brain to bounce around. The woodpecker also has a remarkable tongue structure that wraps up from the lower jaw, around the back of the skull, and over the top of the head, acting as a natural shock-absorbing sling. The Q-Collar attempts to replicate the tight-packing principle by using blood volume rather than anatomy to fill the space around the human brain.
What the Research Shows
The strongest evidence comes from MRI-based studies tracking changes in the brain’s white matter over the course of a sports season. In a study of American football players published in the British Journal of Sports Medicine, researchers compared athletes wearing the collar to a control group over a full season. Brain scans revealed significant changes in white matter integrity among the control group from preseason to postseason. The collar group did not show those same changes.
The numbers tell a clear story on one specific marker of white matter health called axial diffusivity. All 21 athletes in the control group showed decreases in this measure, averaging a 2.43% reduction. In the collar group, results were mixed: 11 out of 21 showed decreases (averaging 0.95%), 8 showed increases, and 2 showed no change at all. The overall average reduction in the collar group was essentially zero at 0.03%.
Similar patterns appeared in studies of other sports. In a study of female high school soccer players, brain imaging during memory tasks showed that non-collar athletes had significantly increased brain activation after one season, a sign the brain was working harder to perform the same tasks. The collar group showed no significant change. Both groups experienced comparable numbers of head impacts during the season, suggesting the difference wasn’t about who got hit more.
These studies across football, hockey, and soccer have consistently shown that the collar group experiences less measurable change in brain structure and function over a season. That said, the collar is designed to address sub-concussive impacts, the hundreds of smaller hits that accumulate over time. It is not marketed or cleared as a device that prevents concussions.
What It Protects Against (and What It Doesn’t)
The distinction between concussions and sub-concussive impacts matters here. A concussion is a single event with noticeable symptoms: dizziness, confusion, headache. Sub-concussive impacts are the routine hits that happen dozens or hundreds of times per season in contact sports. No single one causes obvious symptoms, but the cumulative effect can alter brain structure over time. High school football players average roughly 625 head impacts per season. Soccer athletes experience fewer total impacts but can see higher peak accelerations during headers and collisions.
The Q-Collar targets this cumulative damage. The FDA’s clearance specifically describes it as aiding “in the protection of the brain from effects associated with repetitive sub-concussive head impacts.” It is not a substitute for a helmet, and it does not prevent concussions from a hard enough blow.
Sizing and Fit
The collar comes in four sizes based on neck circumference in inches: SM (11-12), MD (13-14), LG (15-16), and XL (17-18). To find your size, use a soft measuring tape around the middle of the neck, pulled snug with no slack. Measure three times and use the smallest number. A string or shoelace held against a ruler works if you don’t have a measuring tape. Shirt size is not a reliable guide for collar fit, since neck circumference varies widely among people who wear the same shirt size. Proper fit matters because the collar needs to apply consistent, light pressure on the jugular veins to work as intended.
Who Should and Shouldn’t Wear One
The FDA clearance covers athletes aged 13 and older participating in sports activities. It is not cleared for younger children. The device applies pressure to blood vessels in the neck, so anyone with conditions affecting blood flow in that area, such as known vascular abnormalities or conditions that make them sensitive to changes in pressure around the neck, should discuss it with a physician before use. The collar is designed for use during athletic activity, not for extended all-day wear.