What does PEMF stand for?

PEMF stands for “Pulsed Electromagnetic Field”. The term describes the use of low-frequency, pulsed magnetic fields.

Why is PEMF also called a crystal mat or amethyst mat?

Because the common products combine PEMF technology with natural crystals such as amethyst, which store and release infrared heat.

How does PEMF differ from red light therapy?

Red light therapy works with visible and near-infrared light, which is absorbed by the mitochondria of cells. PEMF instead uses pulsed electromagnetic fields. The two technologies are often used to complement each other.

How often should I use a crystal mat?

Several times a week, with sessions of 20 to 30 minutes, is a typical range for comparable products.

For most people, use is considered well tolerated. People with pacemakers, other implanted electronic devices or who are pregnant should seek medical advice beforehand. According to the user manual of the Helsi™ PEMF Mat, this also applies to people with magnetisable prostheses; the mat is not recommended for children who are still growing.

What frequency range does the mat use?

3 to 23 Hz, low-frequency electromagnetic pulses, in four settings: 3, 7.8, 10 and 23 Hz.

How big and heavy is the PEMF Mat?

Unfolded 200 × 80 × 3 cm, folded 80 × 50 × 25 cm. It weighs 18 kg.

What power supply does it need?

220–240 V at 50/60 Hz, up to 250 W: a standard household socket.

Can I use the mat with Helsi™ One Sauna Dome?

Yes. Helsi™ recommends combining it with Helsi™ One Sauna Dome for heat and relaxation at home.

Learn · PEMF

What is a crystal mat? PEMF explained simply

Updated 5 October 2026

A crystal mat – often called an amethyst mat – combines several wellness technologies in a single product.

In short

A crystal mat combines PEMF (pulsed, low-frequency magnetic fields), far-infrared light and natural crystals such as amethyst in one mat. The Helsi™ PEMF Mat has four frequency settings between 3 and 23 Hz (3, 7.8, 10 and 23 Hz), measures 200 × 80 × 3 cm unfolded and runs on 220–240 V at up to 250 W.

Frequency settings: 4 (3–23 Hz)
Session: 20–30 min
Unfolded: 200 × 80 cm
Power: max. 250 W

What is a crystal mat?

“PEMF” is the technical term; many people also call these products crystal mats or amethyst mats.

The three building blocks at a glance:

PEMF: Pulsed Electromagnetic Field
Far-infrared light: also known as type C infrared
Natural crystals: crystals such as amethyst, which store heat and release it evenly

PEMF
Low-frequency, pulsed magnetic fields from coils built into the mat.
Far infrared
Type C infrared heat, released evenly.
Crystals
Natural crystals such as amethyst store the heat and release it slowly.

A crystal mat combines three technologies in one product.

How does PEMF work?

PEMF is based on a basic principle of physics, first described by the physicist Michael Faraday in the 19th century: a changing magnetic field can create a tiny amount of electrical activity in the surrounding tissue. Crystal mats use low-frequency, pulsed magnetic fields generated by coils built into the mat – usually in a low frequency range that is often compared with the Earth’s natural electromagnetic oscillations.

Combined with far-infrared heat, which the crystals in the mat store and release evenly, the result is a session that brings together warmth, gentle electromagnetic pulses and the calming look of the crystals.

The crystals used – often amethyst or tourmaline – have primarily a physical function: they absorb the infrared heat of the mat and release it slowly and evenly, which leads to a gentler, deeper-reaching sensation of warmth than a plain heating mat.

The Helsi™ PEMF Mat works in a range of 3 to 23 Hz and has four frequency settings: 3, 7.8, 10 and 23 Hz.

The Helsi™ PEMF Mat has four frequency settings: 3, 7.8, 10 and 23 Hz.

Where does PEMF come from?

19th century
Faraday describes the principle
The physicist Michael Faraday describes the basic principle of physics on which PEMF is based.
1960s/70s
Systematic basic research
Basic research into electromagnetic fields and their effect on biological tissue goes back to these years: scientists systematically studied how electrical and magnetic stimuli act on tissue.
Over decades
A research field of its own
Over the decades, these early studies grew into a research field of its own.
Today
PEMF, infrared heat and crystals in one mat
Combining PEMF with infrared heat and crystals in a mat for home use is a comparatively recent development that brings several wellness technologies together in an everyday, easy-to-use format.

What is a crystal mat used for?

Evening relaxation: Many people use the mat as a regular part of their evening routine, to wind down after a tiring day.
Warmth and well-being: The even, deep-reaching warmth of the crystals is perceived by many as particularly pleasant.
Addition to an existing routine: Crystal mats are often used alongside other wellness routines such as sauna or cold plunge.
A calm break: The combination of warmth, gentle pulses and the calming look of the crystals is appreciated by many as a conscious moment of slowing down.
Combined with Helsi™ One Sauna Dome: The crystal mat combines very well with Helsi™ One Sauna Dome. While the two infrared domes, including red light, provide pleasant warmth, the crystal mat adds its own effect at the same time – warmth, light and gentle pulses in a single routine.

Man lying with his eyes closed on the Helsi™ PEMF Mat in a bright living room, with the controller beside it

Helsi™ products are not designed to diagnose, treat or prevent diseases. The points above describe general usage habits, not medical promises.

How you could fit a crystal mat into your everyday life

Session length: 20–30 min; depending on your individual needs and preferences
Frequency settings: 4; 3 / 7.8 / 10 / 23 Hz, adjustable to your needs
Time of day: Evening; or during the day as a short, conscious break – both are conceivable
How often: Several; times a week, depending on your personal rhythm and preference

The Helsi™ PEMF Mat

The mat is made of durable ripstop fabric and finished with seven natural gemstones. Unfolded it measures 200 × 80 × 3 cm; folded it stands at 80 × 50 × 25 cm. It weighs 18 kg.

It connects to 220–240 V at 50/60 Hz and draws up to 250 W. It is CE and RCM certified.

The mat has a timer that can be set for up to 8 hours.

Safety and what to look out for

As with any electromagnetic application: if you have a pacemaker or another implanted electronic device, or are pregnant, use PEMF only after explicitly consulting a doctor.

The user manual of the Helsi™ PEMF Mat adds:

Magnetisable prostheses: Please clarify use with a doctor first.
Children who are still growing: The mat is not recommended for them.

PEMF Mat and Helsi™ One Sauna Dome

The mat works on its own. With Helsi™ One Sauna Dome it becomes a heat and relaxation ritual.

All products

Helsi™ PEMF Mat$1,999
The Helsi™ PEMF Mat: four frequency settings from 3 to 23 Hz, seven gemstones.
Helsi™ One Sauna Dome - Sage$5,599.20~~$6,999~~5.0 - 2 reviews
Helsi™ One Sauna Dome: heat and red light in one dome.

Frequently asked questions

Keep reading

Learn · InfraredInfrared saunaHow an infrared sauna works, how it differs from a classic sauna and how Helsi™ One Sauna Dome fits into your everyday life.

Helsi™ products are not designed to diagnose, cure or prevent diseases. All content on this page is for general information only and does not replace medical advice. If you have a pre-existing health condition, please speak to a doctor before use.