Participate in a study on dark retreats this fall.
We are collaborating with Acraya to bring dark-room meditation retreats to HOLOS Diamante, and launching this new offering October 2026 with a formal research study.
Acraya has partnered with the Institute for Advanced Consciousness Studies (IACS) to conduct a study on how the body responds to several consecutive nights in a dark-room retreat setting. Limited spots available.
The study takes place from October 2026 to January 2027.
Two dark rooms, four nights, forty participants.
What the study is looking at
This is a feasibility and tolerability study. Its purpose is to learn whether the study's procedures — enrollment, informed consent, biological sample collection, non-contact physiological monitoring, and data handling — can be carried out reliably at this site, and to document participants' experiences and any adverse effects. The study is not designed to test or demonstrate benefits.
What participation involves
Eligible participants complete a baseline period before the retreat, then four consecutive nights in the dark-room environment. Throughout, non-contact sensors record physiological measures, and saliva and blood samples are collected at defined points. Participants also complete validated questionnaires. Participation is voluntary, and participants may stop at any time.
Research team
The study is led by Principal Investigator Dr. Nicco Reggente (IACS). Dr. Matthew Sacchet, who directs the Meditation Research Program at Harvard Medical School and Massachusetts General Hospital, serves as Co-Investigator and consultant, supporting study design and authorship.
Oversight
The study is conducted under review by a CONIS-accredited ethics committee in Costa Rica and a United States Institutional Review Board.
Details
Dates: October 2026 – January 2027
Pricing: Soft launch - $2,795
Facilitation: Full support is provided throughout — including a preparation session before you enter, check-ins during the retreat, a post-retreat integration session, and remote follow-ups at 7 and 30 days following completion.
Note: This is a research study. Taking part is voluntary. This notice describes the study only and does not offer or imply any therapeutic benefit.
HOLOS × Acraya
HOLOS Diamante was co-founded in collaboration with Stanislav Grof — the pioneering psychiatrist whose foundational research on non-ordinary states of consciousness laid the groundwork for this field. Acraya's mission to create sanctuaries for deep inner exploration is a direct extension of that lineage. This partnership is not incidental — it is a meeting of two organisations built from the same root, on land that has been held for this work for over a decade.
To reserve your spot for a Dark Room retreat outside of the study, you can register here.