We share your concern that with any new product, it is important to evaluate that product's safety profile. The short answer is yes - Halo Sport is very safe! Read on to learn more about the rigorous safety analysis behind Halo Sport and Halo Sport 2.
Halo Sport uses a neurostimulation technique called transcranial direct current stimulation (tDCS). tDCS applies very low levels of constant electrical current to the brain—less current than would light up a typical tiny LED light. tDCS is a powerful way to affect the brain because electricity is the natural language that your neurons use to communicate. When scientists say that a neuron “fires”, they mean that it releases an electrical impulse. This electrical impulse is converted into chemical neurotransmitters which can communicate information to other neurons. Since we’re using such a small amount of electricity, we’re not actually causing neurons to fire or overclocking your brain. Instead, we’re putting the brain in a plastic state, which you can think of as making your neurons more likely to fire together, where and when you want them to.
The Scientific Literature
The type of stimulation used in Halo Sport, known as tDCS, is backed up by two decades of research— 4,200 articles covering over 100,000 sessions speak to the excellent safety profile of tDCS. The regulatory bodies that oversee clinical trials in humans require that researchers report any Serious Adverse Effects, meaning conditions such as death, life-threatening injury, hospitalization, disability or permanent damage, and birth defects . A recent 2016 review article that examined the use of tDCS in over 33,200 sessions and 1,000 people found no reports of a Serious Adverse Effect related with stimulation. Moreover, 2 peer reviewed papers done with Halo Sport speak to the safety of our product.
We have tested Halo Sport on over 1,900 healthy volunteers in our in-house studies. Our data demonstrate an excellent safety profile consistent with the published literature. Read more about our in-house safety study here.
Halo was founded in 2013 by two neuroscientists—an MD and a PhD—who had previously worked together at NeuroPace, a widely successful deep brain stimulation company. Accordingly, Halo Sport was built with medical-grade engineering and rigorous design controls, including safety mitigators—features that ensure that the product is safe, even in unexpected situations.
One of our most important safety mitigators ensures Halo Sport actually delivers the desired amount of electrical current to the brain. In order to make sure this happens, Halo Sport automatically monitors and controls both current and voltage, the force that drives the current through the scalp. If contact between the primers and the scalp is poor, and not enough current is being delivered, Halo Sport slowly ramps down the current and helps you adjust the headset to achieve better contact. If unexpected current is detected for some reason, Halo Sport stops stimulation immediately.
In addition to the safety controls engineered into the product itself, our engineers have put the headset through thorough risk analysis, quality assurance procedures, electronic testing, and mechanical testing to ensure that the headset is 100% safe for its users.
Use in the Real World
Halo Sport is currently safely in use by over 100 partners (including teams, training facilities, universities, and academic labs) and thousands of customers in the real world. In the hundreds of responses we received to our most recent user survey, the most common sensations users reported feeling during our Neuropriming sensations were tingling, improved concentration, and improved muscular control. Only ~5% of users reported mild headaches. In our early safety studies with Halo Sport, headaches did occur very rarely; however, these headaches were less common in the stimulation group than in the placebo (fake stimulation) group. Based on this information, any headaches caused by the headset are most likely a result of the headset's pressure on the head, rather than the stimulation itself.