Vagal Boost

Short answer: no, and if you have a Samsung there is unfortunately no setting that will help.

Samsung phones do not power the Boost. We have seen this consistently across the range: A-series, S-series, Ultra models, the Flip, and Samsung tablets. Samsung handsets do not send power out of their USB-C port to this device. Older guidance suggested enabling a "USB OTG" option in settings; on modern Samsungs that setting does not exist, and on the ones where it does, it makes no difference. If you have gone looking for it and could not find it, nothing is wrong with your phone.

You have not done anything wrong and your Boost is not faulty. Run it from a laptop USB-C port or a USB power bank instead and it will work normally. If you would rather return it, get in touch and we will sort that out without any fuss.

Other Android phones are generally fine plugged straight in. On some older models it is worth checking your settings for a USB OTG or USB power output option and switching it on.

Whichever route you take, do not power the Boost from a mains wall charger. It is meant to run from a battery: your phone, a laptop, or a power bank.

No. Please power it from a battery instead: your phone, a laptop, or a USB power bank.

A mains wall charger will appear to work, and some customers have found this out for themselves, which is why we want to be explicit rather than silent about it. The Boost is designed to run from battery power and that is how it should be used.

If your phone will not power the Boost (which is the case with Samsung handsets), a laptop USB-C port or a small USB power bank is the right answer. A power bank also keeps the setup properly portable, which is rather the point of the device.

It varies. Some people feel calmer during their first session, and some notice very little at first. Use it once a day for four to six weeks before you decide whether it is doing anything for you.

The tragus studies we cite ran from a single session to two weeks of daily use, on research stimulators, so they cannot tell you what you will notice with Boost.

The only parts that touch your skin are the conductive silicone pads. No metal touches your skin, and silicone is naturally latex-free.

The material is a deliberate choice, not a cost saving: conductive silicone’s higher impedance is part of what keeps tENS stimulation gentle and safe, and it is also why lightly dampening the pads before a session makes the sensation smoother.

Boost uses a uniphasic square wave with a 275 microsecond pulse, at 3 to 78 Hz across its six modes, with nine intensity levels. Uniphasic means each pulse flows in one direction only. Boost's pulses are not charge-balanced: there is no opposite pulse to cancel each one. Buddy and Oh! use biphasic pulses instead.

Boost is voltage-controlled. It holds the voltage steady, so the current that reaches your skin can rise or fall as your skin and the paste settle during a session. If the tingle changes, adjust it with + and -.

The only parts that touch your skin are the conductive silicone pads. The lead connects to the clip with two 2 mm stainless steel pins, which sit inside the clip.

Boost is CE marked and FCC Part 15 certified, with a Type BF applied part (body-floating protection against electric shock). Wipe the pads after each session, and stop using Boost if the skin where the clip sits stays irritated. Setup steps are in the Boost instructions.

Vagal Boost is a wellness device, not a medical treatment. It's designed to support your parasympathetic nervous system alongside healthy habits. It is not intended to diagnose, treat, cure, or prevent any disease. If you have a specific medical condition, consult your doctor about whether vagus nerve stimulation might complement your treatment plan.

No. It's a one-time purchase. The device works out of the box with no ongoing costs. Optional replacement ear clips and conductive paste are available from our store when you need them.

Press and hold the M button for about two seconds, until the screen lights up.

A quick tap will not do it. The press has to be held. If your screen is dark, this is the first thing to try. Hold it long enough to say one Mississippi, two Mississippi, and the display comes on.

The Boost has no battery, so it needs to be plugged into your phone, a laptop, or a USB power bank to work. If the screen still stays dark after a proper long press, the port is probably not supplying power rather than the device being faulty. See the separate question on what to check.

Two different things can look like this, and it is worth telling us which one you are seeing.

If it switches off about thirty seconds after turning on, the intensity was probably never set. After you hold M to switch on and choose a mode, you must press + to bring the intensity to at least 1, or the device shuts itself off. The same applies every time you change mode: changing mode resets the intensity to zero, so press + again after each switch. This catches most people out at least once.

If it runs and then drops to zero, first check whether M was pressed, even by accident when you put it down: a short press changes the mode, which resets the intensity to zero. If M was not pressed and it still drops to zero, either as you raise the intensity or after a few minutes at a steady level, please get in touch and tell us the exact point it happens: what level it was on, roughly how long it ran, and what it was plugged into. We are gathering these details to get to the bottom of it, and a precise report from you is genuinely more useful than a general one.

Meanwhile, a gentle, comfortable tingle is the target rather than a strong sensation, and the lower settings are where most people find their result. The full steps are in the Boost instructions.

Two things to rule out first, in this order.

1. Have you pressed and held the M button? If the screen is dark, press and hold M for about two seconds. A quick tap will not do it, and it is an easy step to miss. See How do I turn the Boost on? for what that looks like.

2. If you have a Samsung, that is the answer. Samsung phones do not power the Boost. See the separate question above, and use a laptop USB-C port or a USB power bank instead.

The Boost has no battery. It takes its power from whatever it is plugged into. So once you have ruled out the long press, a dark screen almost always means the port is not supplying power, rather than the device being dead.

Two other things worth ruling out: keep your phone above about 20 percent charge, because below that most phones stop powering accessories entirely; and push the connector fully home, taking a thick case off if it gets in the way and checking the port for pocket lint.

If you have given it a proper two-second press on a laptop or a power bank and the screen is still dark, contact us and we will sort it out.

Please do not use a mains wall charger to power the Boost, even to test it. It is designed to run from battery power: your phone, a laptop, or a power bank.

Yes, more than you would expect.

When a phone runs low, it starts protecting its own battery and reduces or stops the power it sends to accessories. On iPhone this typically happens below around 20 percent. The Boost may then refuse to start, or cut out partway through a session.

For a reliable session, start with your phone above 20 percent. If it is running low, use a laptop USB-C port or a USB power bank for that session instead. Never a mains wall charger: the Boost is designed to run from battery power.

A session uses very little of your phone's battery, so this is about having enough in reserve rather than the Boost draining your phone.