The short version

What it is: a pen-sized, battery-powered stimulator whose metal tip beeps when it finds a low-resistance spot on your skin, then sends a tiny pulsed current into it. Made in Toronto, marketed mainly to therapists, sold to anyone.
Price (as of October 2026): $424 for one unit, or $724 on sale with the ear-clip vagus kit. 30-day money-back guarantee, one-year warranty.
Best for: people whose therapist already uses one for muscle pain and who want to keep going at home.
Skip it if: you want a vagus nerve device for stress or sleep, or you have a pacemaker or are pregnant (both ruled out on its label).
The honest take: it's FDA-cleared, which most devices here can't say, but for sore muscles. The vagus and stress claims rest on two tiny studies without a sham or untreated group, written by the company's own instructors.

Face down on the massage table

It's a quarter to six on a Thursday and you're face down on the massage table, staring at the floor through the paper-covered hole. Something starts beeping, rising in pitch, as a cool metal tip moves across your wrist, then your ear. Your therapist says it's for your vagus nerve, to calm the whole system.

That's how most people meet the Dolphin Neurostim: in someone else's hands. At home you look it up and find a company saying it helps pain, scars, concussion, sleep, anxiety and PTSD. Here's what's underneath.

What it is and how it works

The Dolphin is made by Center for Pain and Stress Research, Ltd., in Toronto, and distributed in the US by Acumed Medical in Florida. Kits now come with the Professional model.

You hold it like a pen, thumb on a metal plate to complete the circuit, and drag the tip slowly over your skin. When it finds a spot of low electrical resistance, the tone rises and a green light flickers off. You press the button for 15 to 30 seconds per point, following a manual of acupuncture and trigger points. The current is direct, pulsing two to three times a second in the tens of microamps, per FDA and engineering documents. Dolphin says it can feel like nothing at all, or a tingle to slight discomfort on tender points.

The vagus setup is a $399 add-on: ear clips and sticky pads wired to the Dolphin for 10 to 12 minutes on the low setting.

Is this a vagus nerve tool?

Only by add-on, and loosely. It's cleared as a TENS unit, like pharmacy pain units, and that clearance never mentions the vagus nerve.

A branch of the vagus nerve does reach your outer ear, mostly in the hollow above the ear canal and less reliably in the tragus, the flap in front of it (the Zappers explains). Dolphin's vagus page says to clip the inner tragus. Its kit page says the earlobe "appears more effective." In ear-stimulation research, the earlobe is a common sham site, because stimulating it isn't expected to reach the vagus nerve.

The settings differ too. Most ear-stimulation trials pulse 20 to 30 times a second at milliamp currents; the Dolphin pulses two or three times a second at a small fraction of that. Whether it reaches the vagus nerve at all hasn't been properly tested.

What the evidence actually says

FDA status: cleared, for pain. The over-the-counter version was cleared in 2015 for temporary relief of sore, aching muscles in the back, arms and legs, based on similarity to older TENS devices and bench testing, not a clinical trial. The prescription versions are listed under a 2003 TENS clearance for chronic pain. Nothing covers stress, anxiety, sleep, scars or the vagus nerve. The label says it isn't effective for headache; one kit page lists migraines and insomnia anyway.

Where the homepage numbers come from:

"+56% vagal tone": 8 people with chronic pain, one five-minute session on ten ear points, before-and-after only (2017). Saliva cortisol fell 14%, not a significant change. At least three authors teach the company's courses; they declared no conflicts.
"+61% HRV": 24 people in two groups of 12, one session each, comparing two stimulation frequencies (2020). No sham, no untreated group. All three authors list the manufacturer among their affiliations.
"-82% pain": 47 people with C-section scars, one session, no comparison group (2019), same team.
"-68% cortisol": it cites a 2017 diabetes journal. The matching paper on Dolphin's site is a one-patient case report, in which "placebo" points also lowered cortisol.

What's missing. We found no randomized, sham-controlled trial of the Dolphin for anything, none registered, nothing independent, and no published study of sleep or anxiety. Its research page even files a 1982 study of electric current on rat skin under "MPS & Diabetes."

Ear stimulation in general has real but mixed trial evidence (the Science explains how to read it). Dolphin's uncontrolled studies don't add to it. Unproven isn't fraud, and a kind session with a skilled therapist can genuinely ease pain. It just isn't proof of the device.

What owners commonly report

The main pool is a Google review widget on Dolphin's own site: 4.8 stars from 170 reviews (as of October 2026). We found no independent reviews on Amazon, Trustpilot or Reddit, and no adverse-event reports in the FDA's database.

Most reviewers are practitioners and course students, from massage therapists to chiropractors, praising scar work, pain relief, the training and fast service. Some home users report less nerve and muscle pain, and one parent credits the vagus kit for a daughter's sleep and anxiety.

Complaints are few: a learning curve, an unanswered support question, a two-unit kit with connections for only one. At least one five-star reviewer is listed as a company instructor. And a recent review featured on the homepage credits it with reviving a woman who'd passed out and restarting periods doctors had called menopause.

Price, returns and training (as of October 2026)

Pain Management Kit: $424 for one unit, case, protocol book, extension probe and 9V battery. Same price in the over-the-counter store.
Scar Release Kit: $749 for two units.
With the vagus kit: $724 for one unit (on sale from $824), $1,049 for two. The kit alone is $399.
Running costs: 9V alkaline batteries every month or two, and replacement vagus pads, one person per pad (Dolphin values 40 at $99).
Training: not required, but finding points takes practice. Kits include a free tutorial; practitioner courses run $399 to $499.
Returns: 30 days, for "the entire system in good condition." Shipping isn't refunded and you pay the return. No free trial, rentals or payment plans.
Warranty: one year; then $50 a unit for repair or $100 to $150 for replacement, plus shipping.
HSA/FSA: we found no program. Dolphin suggests asking your insurer about TENS coverage.
Privacy: no app, no account.

How it compares

Prices as of October 2026.

Truvaga ($325 or $499): a neck device from gammaCore's maker. Not FDA-cleared, but the technology has real headache trials. 30-day refund for first-time buyers.
Pulsetto ($242 to $314): a gel neckband with an app, one small company-funded study and 30-day returns.
Vagustim ($369): a two-ear device with more published studies than most, though small. Returns cost $25.
Hoolest ($199 to $399): a pocket neck stimulator for panic moments, backed by its own unpublished studies.
Free slow breathing: better evidence for your vagus nerve than anything on this list.

The Dolphin is the only one here with an FDA clearance, for sore muscles. As a home vagus setup, it's also the priciest.

Who should skip it or go gently

Dolphin's label and FAQ rule it out with an implanted cardiac pacemaker, in pregnancy, on the front of the neck, in the mouth or across the head, and for undiagnosed pain. The label says to use it under a doctor's supervision and warns it can disrupt electronic monitoring equipment.

The label says nothing about epilepsy, defibrillators or other implants, or heart rhythm problems. Silence isn't a green light: ask your doctor first.

Dolphin's vagus page suggests daily use when you're sick, naming COVID and cancer. Use it alongside treatment, never instead. The same page warns a session right before bed can keep some people awake.

If palpitations, night sweats or 3am wake-ups are new, get checked first, and put HRT on the table in that conversation.

Try this free tonight

The Dolphin holds each point for 20 to 30 beeps. Give your out-breath the same patience: lie down, breathe in through your nose for four counts and out for six to eight, for five minutes. A 2022 review of 223 studies found slow breathing raises the heart rate variability linked to your vagus nerve.

Do it nightly for two weeks. More free options are in the Analogs.

FAQ

Is the Dolphin Neurostim FDA approved?

It's FDA-cleared, not approved, as a TENS device for pain: sore muscles over the counter, chronic pain by prescription. Nothing for stress, sleep or the vagus nerve.

Does Dolphin vagus nerve stimulation work?

Nobody knows yet. The evidence is two small studies by people linked to the company, with no sham or untreated group.

Is the Dolphin Neurostim a TENS unit?

Legally, yes. It uses a much weaker, slower current than a typical pharmacy TENS unit and treats one point at a time.

The bottom line

The Dolphin is a long-running practitioner's tool with a real FDA clearance, for sore muscles. Everything this site cares about, the vagus nerve, stress and sleep, rests on two studies of 8 and 24 people, without a sham or untreated group, from the company's own circle. At $724 for the vagus setup, I'd let a therapist try it on you before buying one.

Tonight, the slow exhale is free, and it doesn't need a battery.

Dolphin Neurostim