In 40 seconds
The shape of a PEMF pulse — its waveform — affects what it does in the body. Square waves produce a sharp on-off pulse, generating strong induced currents at the leading and trailing edges. Sinusoidal waves are smooth and gentle, producing milder cellular effects. Sawtooth waves rise gradually and snap off, producing asymmetric stimulation. Most clinical-grade PEMF systems offer multiple waveforms because different conditions respond best to different shapes. Cheap home devices typically run a single fixed waveform — limiting their clinical versatility.
Quick facts
- Square wave: Sharp on-off — strongest induced currents — bone, deep tissue
- Sinusoidal: Smooth — gentle relaxation, sleep, sensitive use
- Sawtooth: Asymmetric — specific clinical applications
- Trapezoidal: Square wave with ramped edges — clinical balance
- Best systems: Offer multiple waveforms
Practical guidance
See FAQ below for specific scenarios.
Contraindications
Standard PEMF contraindications: pacemakers, defibrillators, cochlear implants, insulin pumps, electronic implants; active malignancy without specialist clearance; pregnancy (over the abdomen); active infection; epilepsy without GP clearance.
Frequently asked questions
Which waveform is best?
Depends on what you're treating. Square waves for bone and deep tissue. Sinusoidal for relaxation and sleep. Different protocols for different goals — best systems offer multiple.
Does a cheap mat with one waveform work?
Often partially. A single fixed waveform limits versatility. Real clinical systems offer multiple programmes targeting different mechanisms.
How can I tell what waveform a device uses?
Spec sheets should specify. If they don't, that's a red flag for a budget device that may not deliver therapeutic doses.
Is one waveform safer than another?
All standard clinical waveforms are safe at therapeutic intensities. Differences are in efficacy, not safety.
Looking for a PEMF clinic near you?
We list every credible PEMF therapy provider in the UK so you can find one near home.