# Do EMF protection stickers, pendants and harmonisers work?

> No — nothing passive of that kind changes a meter reading, and a phone sticker that did block signal would make the phone transmit harder.

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- Collection: Direct answers
- Record id: `questions:do-emf-protection-devices-work`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/questions/do-emf-protection-devices-work
- Also known as: EMF harmonizer scam, do EMF stickers work, EMF protection pendant

## Key values

- **Topic:** shielding

## Question

Do EMF harmonisers, stickers, pendants or 'scalar' devices reduce exposure?

## Answer

No. There is no mechanism by which a passive sticker, pendant, crystal or plug-in 'harmoniser' can reduce field strength, and none of them changes a meter reading — which is exactly the test to demand before buying one. Phone stickers claiming to block radiation cannot do so without degrading the antenna, in which case the handset raises transmit power to compensate. Interventions that do change a measurement are distance, turning transmitters off, wired connections, grounded conductive materials for RF and electric fields, and correcting wiring faults.

## Related records

- [Shielding verification](https://emfbase.com/protocols/shielding-verification): How to prove a shielding measure worked: identical instrument, position and source conditions before and after, reported in dB as well as in absolute units.
- [Wired conversion (Ethernet, corded peripherals)](https://emfbase.com/shielding/wired-conversion): Replacing radios with cable is the only measure that removes an RF source instead of attenuating it, and it is usually cheaper than shielding the room the source sits in.

## Sources

- `sbm-2024` Institut für Baubiologie + Nachhaltigkeit (IBN) (2024). *Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)*. https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf — ngo, link checked 2026-08-12
- `fcc-rf-safety` Federal Communications Commission. *Radio Frequency Safety*. https://www.fcc.gov/general/radio-frequency-safety-0 — government, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.