Why More Microamps Alone Do Not Mean Better Results
Medically reviewed by
4 independent reviewers
Andrew Conrad Barile, PT, DPT
Doctor of Physical Therapy (DPT) | Licensed Physical Therapist (PT) | CEO and Founder, Xtreem Pulse LLC
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Dr. Andrew Conrad Barile is a Doctor of Physical Therapy and the CEO and Founder of Xtreem Pulse LLC, the engineering company behind PureLift. He earned his Doctorate in Physical Therapy from Daemen College and is a licensed physical therapist.
He brings over two decades of clinical and entrepreneurial experience across physical therapy, craniosacral therapy and medical device innovation, built on a working knowledge of human anatomy and muscle physiology.
For PureLift LAB he reviews how current is delivered across all ten levels, from sub-sensory nanocurrent and skin-level microcurrent to motor-level EMS, and how the Infuse pass fits into the same ten-minute routine.
Bertica M. Rubio, M.D.
Board-Certified Physician, Dartmouth Medical School | Medical Director, Antiaging Regenerative Medicine Clinic
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Dr. Bertica M. Rubio is a board-certified physician and Medical Director of the Antiaging Regenerative Medicine Clinic in Redlands, California. She earned her Doctor of Medicine from Dartmouth Medical School and completed her pediatrics residency at UC Irvine Medical Center.
With decades of clinical experience, she specialises in age management medicine, regenerative medicine, wound healing and growth factor therapies, and her practice integrates evidence-based medical science with advanced aesthetic treatment.
For PureLift LAB she reviews articles for medical accuracy across the whole dial, from the gentle nanocurrent and microcurrent settings through to muscle-level EMS and the Infuse pass.
Daniel Grinberg, MD, FACS
Board-Certified Otolaryngologist | Head and Neck Surgeon | Fellow, American College of Surgeons | Mount Sinai
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Daniel Grinberg, MD, FACS is a board-certified otolaryngologist and head and neck surgeon at ENT and Allergy Associates in West Nyack, New York. He earned his medical degree from Columbia University College of Physicians and Surgeons.
He completed his otolaryngology residency at New York University Medical Center, serves as Assistant Clinical Professor at Mount Sinai School of Medicine, and is a Fellow of both the American College of Surgeons and the American Academy of Otolaryngology.
For PureLift LAB he brings a wider clinical lens, connecting at-home facial stimulation from microcurrent to EMS to the anatomy underneath, with the same rigour we apply to every device specification.
Prof. Dr. med. Ivo Buschmann
Chair of Angiology, Medizinische Hochschule Brandenburg | Clinic Director, University Clinic for Angiology
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Prof. Dr. med. Ivo Buschmann is Chair of Angiology at the Medizinische Hochschule Brandenburg Theodor Fontane and Clinic Director of the University Clinic for Angiology at the Brandenburg University Hospital.
He trained at the University of Hamburg, was a Max Planck Society Fellow at the Max Planck Institute for Heart and Lung Research, and held senior consultant posts at the Charite Universitatsmedizin Berlin before his appointment as Chair in 2016.
One of Europe's leading authorities on arteriogenesis, with over 150 peer-reviewed publications and US and EU patents, he reviews for PureLift LAB how the evidence on electrical stimulation is read and where its limits lie.
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Current output is the number brands publish because it is the easiest one to put on a box, and it is one of five things that decide what actually reaches the tissue.
This article covers what actually decides the answer, such as:
- The threshold is binary, the rest is not
- Impedance, the missing half of the number
- Pulse width
- Frequency
- Contact and placement
and many more!
This is also why a level 5 on one brand tells you nothing about a level 5 on another.
Key Points:
A current figure without a stated impedance is half a number; PureLift publishes 7 mA at 500 ohms for a reason.
Pulse width decides how much charge each pulse actually carries; PureLift Face and Pro use 4 microseconds.
Frequency decides comfort over a ten minute session more than it decides power.
Dry skin or a dirty probe can cost you more than two levels on the dial.
Crossing the motor threshold is a yes or no question; beyond it, higher is not automatically better.
The threshold is binary, the rest is not
Ward's work describes three thresholds as current rises: sub-sensory, sensory, and motor, the last being where a nerve fires a muscle (PMID 19095805).
Reaching the third threshold is the one place where the output number is decisive, because below it the muscle does not contract at all. A device publishing 500 microamps cannot get there and a device publishing 7 mA can.
Past that point the picture changes. More current recruits more muscle fibres, up to a point, and then it mostly recruits more discomfort, and discomfort is the reliable predictor of a device left in a drawer.
Impedance, the missing half of the number
Current depends on the resistance it meets, and skin resistance varies with how damp it is, where on the face you are working, and whose face it is.
So a bare milliamp figure is incomplete. PureLift publishes 7 mA at 500 ohms for Face and Pro, 7.7 mA for Pro Edition, and 9 mA for Pro Plus and GLOW, with the load stated, because without the load the figure cannot be checked against anything.
Pulse width
Current tells you the height of each pulse and pulse width tells you how long it lasts, and charge delivered is a function of both. Two devices at the same peak current with different pulse widths are not delivering the same thing.
PureLift Face and Pro use a 4 microsecond pulse. Most brands do not publish this figure at all, which is worth noticing when a comparison table looks tidy.
Frequency
Frequency does not set the power; it sets how the power lands over time. Hold one fixed frequency and the nerve accommodates, so the response falls off while the current stays the same.
PDM cycles through 361 points between 1,370 and 1,730 Hz rather than holding one, which delays that decline. Downey and colleagues tested the principle in a neuromuscular protocol (PMID 21996798), and Papaiordanidou and colleagues report a case where modulation did not help (10.1371/journal.pone.0084740).
Pro Plus and GLOW add PDM++, a bipolar pulse that builds and releases charge gradually so the same power lands more smoothly.
Contact and placement
These are the two that cost people the most and appear in no specification at all.
Dry skin raises resistance sharply, and a session that fades halfway through is almost always a dry patch rather than a weak device; reapply serum instead of climbing the dial. Residue on the probe does the same thing more slowly, so clean it after every session.
Placement decides which muscle you are working. The current goes where the probe is, and a technically perfect session on the wrong part of the face achieves the wrong thing.
Why level numbers do not travel
Maffiuletti's work makes the underlying point that a dial setting is not the same as the tension actually evoked in the muscle (PMID 29233625).
Ten levels on one device and ten on another are ten divisions of two different ranges. Comparing them as though they were the same scale is the most common mistake in this category, and it is encouraged by every brand that publishes a level count instead of an output.
What to ask before buying
Maximum current, and the impedance it was measured at. Pulse width. Whether the frequency is fixed or varied. What conductive medium is required and what it costs.
Four answers, and most brands cannot give you more than one of them.
Three minutes per side is the maximum on any PureLift model, and the ten minute session ends on its own. For the full breakdown, see how the nine PureLift technologies work.