Microamps Explained, What 335, 500 and 680 Really Mean
Medically reviewed by
4 independent reviewers
Andrew Conrad Barile, Physiotherapeut, Doktor der Physiotherapie
Doktor der Physiotherapie (DPT), Lizenzierter Physiotherapeut (PT)
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Dr. Andrew Conrad Barile ist Doktor der Physiotherapie sowie CEO und Gründer von Xtreem Pulse LLC. Er erwarb seinen Doktortitel in Physiotherapie am Daemen College und bringt über zwei Jahrzehnte klinische und unternehmerische Erfahrung in der pädiatrischen Physiotherapie, Craniosacraltherapie und medizinischen Geräteinnovation mit. Sein tiefes Verständnis der menschlichen Anatomie, Muskelphysiologie und therapeutischen Technologie bietet einen wissenschaftlich fundierten Ansatz für Gesichtsverjüngung und Anti-Aging-Lösungen.
Bertica M. Rubio, M.D.
Medizinischer Direktor, Anti-Aging-Regenerationsmedizinische Klinik | Facharzt | Dartmouth Medical School
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Dr. Bertica M. Rubio ist eine zertifizierte Ärztin und medizinische Leiterin der Anti-Aging-Regenerationsklinik in Redlands, Kalifornien. Sie erwarb ihren Bachelor of Science an der Loyola Marymount University und ihren Doktortitel in Medizin an der Dartmouth Medical School (Geisel School of Medicine). Ihre Facharztausbildung in Pädiatrie absolvierte sie am UC Irvine Medical Center.
Mit jahrzehntelanger klinischer Erfahrung spezialisiert sich Dr. Rubio auf Altersmanagement, regenerative Medizin, Wundheilung und Wachstumsfaktor-Therapien. Ihre Praxis verbindet evidenzbasierte medizinische Wissenschaft mit fortschrittlichen ästhetischen und regenerativen Behandlungen, um Patienten zu optimaler Gesundheit und jugendlicher Vitalität zu verhelfen.
Dr. Rubio ist leidenschaftlich daran interessiert, Patienten über die Wissenschaft hinter Hautpflege, Gesichtsverjüngung und nicht-invasiven Technologien wie EMS (Elektrische Muskelstimulation) zur Gesichtstonung aufzuklären. Ihre Artikel für PureLift LAB verbinden fundiertes medizinisches Wissen mit praktischen Anleitungen für echte, nachhaltige Ergebnisse.
Daniel Grinberg, MD, FACS
Facharzt für Hals-Nasen-Ohren-Heilkunde und Kopf-Hals-Chirurgie | Fellow des American College of Surgeons | Assistenz-Professor für Klinische Medizin, Mount Sinai School of Medicine
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Daniel Grinberg, MD, FACS, ist ein von der Ärztekammer zertifizierter Hals-Nasen-Ohren-Arzt und Kopf-Hals-Chirurg bei ENT and Allergy Associates in West Nyack, NY. Er erwarb seinen medizinischen Abschluss an der Columbia University College of Physicians and Surgeons, absolvierte seine Facharztausbildung in Hals-Nasen-Ohren-Heilkunde am New York University Medical Center und ist Assistenzprofessor an der Mount Sinai School of Medicine. Er ist Fellow sowohl des American College of Surgeons als auch der American Academy of Otolaryngology.
Dr. Grinbergs Perspektive als Kopf-Hals-Chirurg bietet den Lesern von PureLift LAB eine erweiterte klinische Sichtweise — er verbindet die EMS-Anwendung zu Hause mit der zugrunde liegenden medizinischen Anatomie mit derselben wissenschaftlichen Genauigkeit, die wir auf jede Gerätespezifikation anwenden.
Prof. Dr. med. Ivo Buschmann
Lehrstuhl für Angiologie, Medizinische Hochschule Brandenburg | Klinikdirektor, Universitätsklinik für Angiologie, Brandenburgisches Klinikum | Ehemaliger Oberarzt, Charité Universitätsmedizin Berlin
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Prof. Dr. med. Ivo Buschmann ist Lehrstuhlinhaber für Angiologie an der Medizinischen Hochschule Brandenburg Theodor Fontane (MHB) und Klinikdirektor der Universitätsklinik für Angiologie am Brandenburgischen Universitätsklinikum. Er absolvierte seine medizinische Ausbildung an der Universität Hamburg, war Max-Planck-Gesellschaft-Stipendiat am Max-Planck-Institut für Herz- und Lungenforschung und hatte leitende Oberarztpositionen an der Charité Universitätsmedizin Berlin Campus Virchow inne, bevor er 2016 zum Lehrstuhlinhaber an der MHB berufen wurde.
Prof. Buschmann ist einer der führenden europäischen Experten für Arteriogenese – das durch Fluss angetriebene Wachstum und die Umgestaltung von Blutgefäßen – mit mehr als 150 begutachteten Veröffentlichungen und mehreren US- und EU-Patenten für Geräte, die das Wachstum von Kollateralgefäßen durch kontrollierte Scherkräfte-Therapie stimulieren. Seine Forschung verbindet mechanische und elektrische Stimulation mit vaskulärer Anpassung, Mikrozirkulation und Gewebeperfusion.
Die Beiträge von Prof. Buschmann bieten den Lesern von PureLift LAB eine gefäßbiologische Perspektive, die unsere bestehenden Autoren aus den Bereichen Klinik, Physiotherapie und chirurgische Anatomie ergänzt – und erklären, wie EMS-Stimulation nicht nur die Gesichtsmuskeln, sondern auch die Mikrozirkulation, die sie versorgt, aktiviert und warum eine intelligente Anwendung auf der Ebene des Blutflusses ebenso wichtig ist wie die Muskelkontraktion.
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A microamp is a millionth of an amp, every consumer microcurrent device quotes a few hundred of them, and all of those figures sit in the same band well below the level that moves a muscle.
This article explains what is actually happening, such as:
- what a microamp is, in terms you can picture
- why 335 and 680 are closer together than they look
- where the sensory and motor thresholds actually sit
- what the missing load and pulse width would tell you
- what each band of current can and cannot do
and many more!
The unit is simple; what brands leave off around it is where the difficulty lives.
Key Points:
A microamp is one millionth of an amp, and a milliamp is one thousandth, so 1 mA is 1,000 microamps.
Consumer microcurrent devices publish figures between about 200 and 680 microamps, all inside the same sub-sensory to barely-sensory band.
Muscle contraction needs current in the milliamp range, which is roughly an order of magnitude or more above any of those figures.
A current figure means little without the load it was measured at, because current through skin depends on resistance.
Pulse width matters as much as current, since tissue responds to charge, which is current multiplied by duration.
What the unit actually is
An amp measures the rate at which electrical charge flows. A milliamp is a thousandth of an amp, and a microamp is a millionth, so a thousand microamps make one milliamp.
For scale, a household circuit breaker trips somewhere around 13,000 to 30,000 milliamps, a TENS unit for pain typically works in the tens of milliamps, and a microcurrent facial device works in the hundreds of microamps, which is well under a single milliamp.
So when a brand quotes 500 microamps, it is quoting half of one milliamp. The number sounds substantial because the unit is small, which is part of why the unit gets used.
Why 335 and 680 are closer than they look
Across the devices that publish anything, Solawave gives about 200 microamps, ZIIP publishes 309, NuFACE files 335 with the FDA, 7E publishes 350 at 500 ohms, Therabody gives 500, and FOREO publishes 680.
Doubling from 335 to 680 sounds like a large difference, and in terms of what physically happens in tissue both figures sit comfortably inside the same band, below the level at which a motor nerve depolarises.
Ward and colleagues described the thresholds separating sub-sensory, sensory and motor stimulation, and the practical consequence is that moving from 335 to 680 microamps changes how much you feel rather than what category of effect you get.
7E Wellness states the point plainly in its own FAQ: true microcurrent is sub-sensory and cannot cause a physical or visual manipulation of the muscle. That is a manufacturer describing its own product accurately.
Where the motor threshold sits
To make a facial muscle contract, the current has to depolarise the motor nerve supplying it, and that takes current in the milliamp range rather than the microamp range.
Ya-Man's FDA filing for the Medi Lift PLUS publishes 3.22 mA at 500 ohms, which is about 3,220 microamps. PureLift publishes 7 mA at 500 ohms on Face and Pro, 7.7 mA on Pro Edition and 9 mA on Pro Plus and GLOW.
Kavanagh and colleagues measured an 18.6 percent increase in cheek muscle thickness across 108 women over twelve weeks using motor-level stimulation, which is the band those milliamp figures sit in rather than the microamp band.
None of that makes microcurrent useless. Avendano-Coy and colleagues reviewed microcurrent in wound healing and found measurable effects at sub-motor intensities, which is the honest case for the band: real effects at skin level, not muscle work.
The two numbers that are missing
The first is the load. Current through skin depends on the resistance it meets, so the same device measured into 500 ohms reads differently from the same device measured into 10,000 ohms, and both readings are true.
Of 33 devices we track, six publish an output figure on their own page and two state the load, which means most of the microamp figures in this market cannot be compared with each other at all.
The second is pulse width. Tissue responds to charge, which is current multiplied by how long each pulse lasts, so a device at 500 microamps with a long pulse delivers far more charge than one at 500 microamps with a short one.
7E's filing for the MyoLift QT gives pulse durations measured in hundreds of thousands of microseconds at frequencies below one hertz, while our devices run a 4 microsecond pulse at a much higher current. Those are entirely different delivery strategies that a single microamp figure hides.
What each band can do
Nanocurrent and low microcurrent, below roughly 100 microamps, is sub-sensory territory where you feel nothing and the claimed effects are cellular.
Microcurrent from roughly 100 to 1,000 microamps is where most consumer devices sit, producing skin-level effects and a mild tingle at the upper end.
Above about 1 milliamp, with the right pulse and frequency, you enter the band where the muscle responds and you can see the contraction in the mirror.
Which band your device occupies decides what is available to you, and the published figures for 33 devices will tell you where yours sits.
How to use the number when shopping
Treat a bare microamp figure as a rough indication of sensation rather than as a specification.
Ask for the load in the same breath, and treat a brand that cannot answer as having told you something anyway.
Ask for pulse width, which almost nobody publishes and which changes the picture completely.
And decide first which band you actually need, because a buyer who wants skin-level effects is well served by a good microcurrent device, while a buyer who wants contour change is not, whatever the microamp figure says.
This article sits inside our full map of the category, where we set out all 33 devices we track, what each one carries and what each brand publishes: Nine Technologies on One Dial, What the Rest of the Market Actually Carries.