The “best” anti-radiation case is typically the one that meets three criteria

If your objective is to reduce exposure in a practical, physics-consistent way without increasing phone transmit power, the “best” anti-radiation case is typically the one that meets three criteria:

1. Directional shielding (not full enclosure) so it can act as a barrier between you and the phone during a call.

2. Minimal antenna interference risk (no designs that commonly degrade signal and trigger the phone to work harder). The FTC explicitly warns that products that interfere with a phone’s signal can cause it to draw more power and possibly emit more radiation.

3. Clear, behavior-based use guidance (because the same case can perform very differently depending on orientation and real-world use).

Best overall to consider (for most people): a directional folio-style shielding case you will actually use correctly

RF Safe QuantaCase / TruthCase is a strong “best overall” candidate if you are willing to use it as intended (front flap between you and the phone during calls, and correct body-side orientation in pockets). RF Safe’s positioning emphasizes correct use over blanket percentage claims, and it repeatedly frames “percentage marketing” as misleading because results vary by orientation and real-world conditions.

Why that matters: consumer-protection guidance consistently stresses that “shielding” accessories can be ineffective if they only cover part of the device, and they can be counterproductive if they interfere with signal.

What to be cautious about: detachable magnetic wallets and “blocks 99%” style claims

Be especially careful with detachable, magnet-based wallet systems or designs that rely on magnetic plates. Even the vendor’s own product descriptions can confirm the presence of magnets and detachable plates—features that create a higher risk of antenna interaction depending on phone model and placement.

More broadly, the FTC cautions against “shield” products that claim major reductions and notes that signal interference may increase emissions.
Separately, EWG highlights that some cases can increase measured exposure (its analysis references lab data submitted to the FCC by Pong Research) and explains the mechanism: obstructing antenna performance can make the phone work harder.