PEMF field claims explained: why "up to X gauss" is not a spec

What a PEMF field claim should contain

A usable field claim has three parts: a field strength in real units (microtesla or gauss, where 1 gauss equals 100 microtesla), the frequency it runs at (in hertz), and ideally the waveform (square, sine, sawtooth, and so on). All three matter together. The same field strength at 3 Hz and at 300 Hz are different things, and a peak value reached for a fraction of a millisecond is different from the field sustained during a session. When a brand publishes a field strength at a stated frequency, you can compare it to the next device. When it does not, you cannot.

The peak-gauss trick

The most common move is to headline a peak: "up to 200 gauss," "up to 12,000 gauss." That figure is the momentary maximum a sharp pulse touches, often measured right at the coil. It is real in the narrow sense, and useless as an operating spec, because it tells you nothing about the field at a stated frequency over a session. This is the direct analog of a red light panel quoting irradiance at its surface instead of at a treatment distance, or a sauna quoting EMF at the heater instead of the seat. So when a device leads with a peak and no sustained field at a stated frequency, RecoveryScored caps and flags its field dimension. A disclosed waveform earns a little partial credit for the engineering transparency, but the cap stays until there is a real spec.

The unit-less-level trick

The second move is to drop units entirely: an "intensity level" dial from 1 to 10, or a frequency described only by program name. There is nothing to verify there, no microtesla, no gauss, no hertz. A coverage area ("a 22-inch field") is not a field strength either. We treat a unit-less level or a missing figure as the weakest tier, below even a peak number, because at least a peak is in real units.

FDA cleared vs FDA registered

The regulatory story mirrors red light. Many PEMF devices advertise "FDA registered" or "FDA-registered Class 1," which is paperwork any maker files to sell a device; it is not a finding about the device. A real FDA 510(k) clearance, for a specific use, is rare in consumer PEMF, more common in medical bone-growth stimulators. A small number of consumer systems do hold genuine clearances, and we credit those. We flag "registered" used as if it were a clearance, and we score a device making no FDA claim above one that dresses registration up as one.

What to actually look for

Ask four questions. First, is there a field strength in microtesla or gauss published with a stated frequency in hertz, not just a peak? Second, is the waveform disclosed? Third, is the FDA claim a real 510(k) clearance, or just registration? Fourth, is the price reasonable for its format, mat, coil, or wearable? Those four separate a device whose engineering you can read from one selling a number with no context.

Browse the scored PEMF devices, see the verified-field-spec shortlist, or read the methodology. This is general information about specs, not medical advice, and not a claim about what PEMF does.