Research Device

A Silicone Ring Supplied for Research

The Circunaro ring is a medical-grade silicone ring that holds the foreskin retracted. It is no longer sold to the public and is now supplied only for research studies. Any effect on the penile microbiome is a research hypothesis under investigation; the ring does not treat, prevent or cure any disease.

The Circunaro ring — a translucent medical-grade silicone device
What It Is

Medical-Grade Silicone, Non-Invasive Design

Material
Medical-grade platinum-cured liquid silicone (SILPURAN 6600/40, Wacker Chemie)
Mechanism
Holds the foreskin retracted, exposing the glans to air
Use
User-controlled and reversible; removed daily for hygiene and always before sexual intercourse
Safety documentation
Biocompatibility, risk analysis and post-market surveillance documentation available to research partners on request
Regulatory History

From Medical Device to Research Device

The ring was first CE-marked in 2019 as a Class I medical device for premature ejaculation due to genital hypersensitivity. The CE mark was later voluntarily withdrawn when the product was repositioned, and since December 2024 it has been a consumer hygiene product under the EU General Product Safety Regulation (2023/988). It is not currently CE-marked and holds no regulatory approval as a medical device.

  1. Jan 2019 CE marking as a Class I medical device under Directive 93/42/EEC (original indication: premature ejaculation due to genital hypersensitivity).
  2. Dec 2024 Product repositioned as a consumer hygiene product under the General Product Safety Regulation (EU) 2023/988. CE mark voluntarily withdrawn.
  3. 2025–2026 Sales to the public ended. The ring is supplied only for research.
  4. 2026 ADJUNCT-SYPH, a pilot study with partners in Rakai, Uganda, is in preparation. It is not yet funded and is pending ethics review.
Circunaro ring packaging

The ring's packaging from its commercial period (2019–2025). The ring is no longer sold to the public.

Safety

What We Can and Cannot Say

Regulatory status
Not CE-marked and not an approved medical device. Previously CE-marked (Class I, 2019); mark withdrawn.
Intended use
Male genital hygiene device for adult men with an intact foreskin. It does not treat, prevent or cure any disease or infection and is not a contraceptive.
Customisable design
Users can trim the male end of the interlocking ring for a personalised fit. It is removable at any time.
Evidence
We have no clinical evidence that the ring changes the penile microbiome or reduces BV in female partners. Testing this is the aim of the studies we support.
For Research Teams

Available to Qualified Investigators

We supply the ring for research studies and are open to sharing the design with qualified investigators. We place no restrictions on the publication of research results, including negative findings.

  • Device supply at cost (materials + shipping only)
  • Technical file and biocompatibility documentation
  • Scientific rationale and literature review support
  • Willingness to co-develop study protocols
  • No restrictions on publication of results
  • Open to co-authorship arrangements
Enquire about collaboration