Forty-six American military veterans and first responders spent a week at an ayahuasca retreat in Guanacaste in September, hoping the Amazonian brew would ease trauma they carried home from combat zones and emergency scenes. Their accounts, published Wednesday by the New York Post, describe former Army Rangers and Navy SEALs weeping in ceremony tents and returning home calmer.
The stories are moving. They also land in a place where the Ministry of Health has spent nearly two years warning the public against therapeutic ayahuasca use, while the best-known center that serves it holds a ministry authorization the ministry itself tried, and failed, to cancel.
The retreat ran from Sept. 5 to 12 at Rythmia Life Advancement Center near Tamarindo, in the area of Santa Cruz, spanning the 25th anniversary of the Sept. 11 attacks. It was organized with The Coming Home Project, a nonprofit founded in 2021 by Navy SEAL veteran Nate Brown to combat veteran suicide, and funded largely by the Birds Eye View Project, a Texas veterans charity, according to the organizers.
The Post put the group at 46, while a September press release from the organizers said 47 took part. Days combined yoga, individual and group counseling, classes and meditation, with ayahuasca ceremonies held at night in tents. Rythmia and Coming Home reviewed each participant’s medical history, medications and mental health beforehand, the Post reported.
The need behind such efforts is stark. A 2026 Department of Veterans Affairs report counted 6,488 veteran suicides in 2024, an average of nearly 18 a day. Participants described the week as a turning point. A 44-year-old firefighter and former Army Ranger, identified only as Dave L., told the Post that the constant inner conflict he lived with had grown much quieter since he returned home. He stopped short of calling a single retreat a cure.
Jeff McNairy, Rythmia’s chief medical officer and a psychiatrist, told the paper that trauma is the condition he considers ayahuasca best suited to treat. He said roughly half the participants vomited on any given night, a reaction the center describes as a psychosomatic release of trauma.
What the coverage does not include is outcome data. No standardized symptom scores, follow-up assessments or comparison group were reported for the group. Rythmia advertises a self-reported success rate above 97% among more than 23,000 guests since 2016, a figure drawn from its own guest surveys rather than independent clinical measurement.
The broader research is promising but young. An observational study run with the nonprofit Heroic Hearts Project followed 58 veterans who attended ayahuasca or psilocybin retreats in Peru and Jamaica between 2021 and 2024. Its research director, neuroscientist Grace Blest-Hopley, has said more than 80% of those who entered with PTSD no longer met the diagnostic criteria afterward.
The study’s published averages were more modest, with PTSD symptom scores falling about 26% among the ayahuasca group. Researchers at the University of Texas are now studying how brain responses in combat veterans change after ayahuasca treatment. None of this yet amounts to the large controlled trials regulators require before approving a treatment.
The risks are well documented. About 70% of users experience acute nausea and more than half report unsettling psychological effects, according to research cited by the Post. Combined with common SSRI antidepressants, the brew can trigger serotonin syndrome, which can be fatal, and it can provoke prolonged psychosis in people with underlying psychiatric vulnerabilities.
Those medications and histories are common among veterans with PTSD, which is why screening matters as much as the ceremony itself. Costa Rica has no law written for this industry. In January 2025 the Ministry of Health issued a health warning on ayahuasca and ibogaine, urging the public not to consume or promote either for therapeutic purposes, not to join rituals that use psychoactive substances for healing, and to report anyone offering them.
The ministry said no product based on either plant holds the sanitary registration it requires. Rythmia is the exception, and an awkward one. The center promotes itself as the world’s only medically licensed ayahuasca center, with a round-the-clock medical team that McNairy said includes five doctors and 12 registered nurses.
According to a February 2025 opinion from the Attorney General’s Office (PGR), the Ministry of Health told Rythmia in July 2022 that it could keep using ayahuasca for therapeutic purposes on a temporary basis until a regulation was issued. In October 2024, Health Minister Mary Munive asked the PGR to endorse annulling that authorization.
The PGR declined and said the ministry’s request contained extremely serious errors, including a failure to identify which rules the authorization violated, and noted that no regulation governed or banned ayahuasca when the permission was granted. It is not clear whether the ministry has revisited the case since.
Elsewhere, safeguards vary widely. A study published in January in JAMA Network Open interviewed representatives of 49 publicly advertised psychedelic retreat organizations, most of them based in the United States. About seven in 10 worked with a licensed health professional or someone trained in emergency response, but only about two-thirds had such a person present at retreats even some of the time.
By one estimate, Costa Rica hosts about 80 psychedelic retreat centers, some 60 of them offering ayahuasca, making it the second most popular destination for this kind of travel after Peru.
The consequences of thin oversight have already been felt here. Lauren Levis, a 40-year-old social worker from New Mexico, died in August 2024 after taking iboga at Soul Centro, a retreat in Paquera on the Nicoya Peninsula. Her brother has said she collapsed in a shower after an all-night ceremony, and that an electrocardiogram taken before the retreat showed marked abnormalities, yet she was allowed to attend.
Judicial investigators sent their findings to prosecutors in March 2025, nearly eight months after her death. A Norwegian woman died after taking ibogaine at another facility near Liberia in 2014. The veterans’ relief may prove genuine, and researchers are working to measure how much of it lasts. For now, the safeguards around ayahuasca in Costa Rica depend largely on the operators who serve it.
Researchers who study the retreat industry advise anyone weighing one to ask for a written medical screening that covers heart conditions, psychiatric history and every medication, a medical professional on site rather than on call, a clear emergency plan with transport to the nearest hospital, and straight answers about the legal status of what is being served. Medical experts also warn that safely tapering off antidepressants can take six to 12 weeks under supervision, far longer than many retreats allow.
