You are comparing two eco-lodges. One carries a small green badge. The other does not. The badge feels like the tiebreaker, because a badge usually means somebody checked.
Here is where that badge most often traces back to. The Global Sustainable Tourism Council writes the standards that many tourism seals are measured against. It is a private nonprofit registered in Washington, DC, and it does not certify a single hotel, tour operator or retreat.
At the other end of the same market, in the corner growing fastest and examined least, the US State Department says of two countries that the facilities selling the experience are not regulated by the host government at all.
Different ends, same gap. Wellness travel is sold in the vocabulary of verification. Much less of it is verified than the vocabulary suggests.
The organization behind the standards does not certify anybody
The Global Sustainable Tourism Council, usually shortened to GSTC, is the body most often invoked when a travel business wants to sound checked. Its own website is blunt about the limits of what it does: “GSTC does not directly certify any products or services; but provides an accreditation program for certification bodies.”
That single sentence undoes most of the marketing built on top of it.
GSTC is not a United Nations agency, not an intergovernmental organization and not a regulator. IRS filings published through ProPublica’s Nonprofit Explorer show it as a 501(c)(3) tax-exempt nonprofit, EIN 46-1050633, based in Washington, DC, reporting about $2.2 million in revenue for the fiscal year ending December 2025. You will sometimes read that it was founded by the UN. No primary GSTC source confirming that was reachable for this article, so treat the claim as unverified rather than repeating it.
What matters more is that GSTC uses three words that sound interchangeable and are not.
Recognition is a status GSTC gives to somebody else’s set of standards, after deciding those standards are equivalent to its own. It says nothing about how, or whether, anyone audits a business against them.
Accreditation is a mark GSTC places on a certification body, meaning GSTC has checked that organization’s process for auditing businesses.
Certification is the audit of an actual hotel, tour or destination. GSTC does not do it. Independent certification bodies do.
So a “GSTC-Recognized” label is a claim about a rulebook, and “GSTC-Accredited” is a claim about an auditing firm. Neither says anyone inspected the property you are about to book.
Tourism seals sit almost entirely with the private certifiers, one step further removed than most travelers assume and a long way from anything written into law. Article 748 covers how to sort seals generally.
What the standards ask of a hotel
The criteria themselves are more concrete than the badges. GSTC’s industry criteria document is organized into four sections: effective sustainable management, social and economic benefits to the local community, benefits to cultural heritage, and benefits to the environment. Each section breaks into numbered sub-criteria covering things like a written sustainability management system, legal compliance, local hiring, local purchasing, and conserving water and energy.
One detail worth knowing before you weigh a seal heavily. The industry criteria file GSTC hosts is Version 3, dated 21 December 2016. GSTC’s own overview page says the criteria are revised every few years, and a Purdue University report hosted on the GSTC site refers to Destination Criteria 2.0. GSTC’s criteria index pages would not load during the research for this article, so the current version number could not be confirmed. A standard you cannot date is a standard you cannot fully evaluate.
The underlying definition is older and broader than most people expect. A 2005 guide from the UN Environment Programme and the World Tourism Organization states that sustainable tourism guidelines apply to all forms of tourism in all types of destinations, including mass tourism, and that environmental, economic and socio-cultural aspects must be balanced. It sets out 12 aims, among them local prosperity, employment quality, community wellbeing, cultural richness, resource efficiency and environmental purity. Sustainable tourism, in its original official sense, was never a boutique category. It was a way of running any tourism at all.
Some of this is measurable. Research by scientists at the European Commission’s Joint Research Centre, published in Tourism Management, set best-practice benchmarks for total water use at 140 litres or less per guest-night in fully serviced hotels, 100 litres or less in hostels and 58 litres or less on basic campsites, and estimated that widespread best practice could cut European water use by at least 422 million cubic metres a year. Those are numbers you can ask a property about. A badge is not.
Two carbon figures that are not in conflict
You will see tourism’s climate footprint given as 5 percent and as 8 percent, usually with the implication that experts disagree. They do not. The two numbers count different things in different years.
The 5 percent comes from a December 2019 report by the World Tourism Organization and the International Transport Forum. It found transport-related tourism emissions of 1,597 million tonnes of CO2 in 2016, which it put at about 22 percent of all transport emissions and 5 percent of overall manmade emissions of 32,100 million tonnes. That figure counts transport only, and it includes cruise ships. The same report forecast 1,998 million tonnes by 2030, or 5.3 percent of expected manmade emissions, but that forecast excludes cruise. The two are not a like-for-like series.
The 8 percent comes from a 2018 study in Nature Climate Change led by Manfred Lenzen at the University of Sydney. Tracing tourism-related carbon flows between 160 countries, it found tourism’s global carbon footprint rose from 3.9 to 4.5 gigatonnes of CO2-equivalent between 2009 and 2013, about 8 percent of global greenhouse gas emissions, and four times more than previously estimated. That number counts the whole trip: transport, yes, but also food, accommodation, shopping and the goods behind them.
Transport-only CO2 for 2016 versus the full greenhouse-gas footprint for 2013. Use one or the other, never both as though they were rival guesses at the same quantity. The practical lesson sits in article 761: what a footprint number means depends entirely on where the accountant drew the line.
Note that UNWTO renamed itself UN Tourism in 2024. Older reports, including the 2019 transport study, carry the old name.
Overtourism is a measured condition, not a mood
The European Parliament’s Committee on Transport and Tourism commissioned a study on overtourism, completed in October 2018 by Paul Peeters and colleagues. It is the most rigorous public treatment of the term, and it defines it carefully: overtourism describes a situation where tourism’s impact, at certain times and in certain places, exceeds physical, ecological, social, economic, psychological or political capacity thresholds.
The researchers looked at over 290 regions, found 53 with at least one destination already facing overtourism, and discussed 41 case studies. Roughly 25 percent of international tourists felt their destination had been overcrowded, and 9 percent said the crowding hurt the quality of their trip.
The study is also honest about its limits, stating that it is difficult to assign a general value or threshold to any individual indicator or combination of them. There is no number above which a place is officially overtouristed.
Two cautions. The work predates the 2020 collapse in travel and the rebound that followed, so treat it as a framework rather than current data. And a companion 2018 UNWTO report on resident perceptions in eight European cities proposed 11 strategies and 68 measures, all of them for destinations rather than visitors. Crowding is a local policy problem. One traveler’s booking is a very small lever on it.
Plant-medicine retreats, where nobody is regulating anything
This is the part of wellness travel readers most need information about, and it is where the gap between marketing and oversight is widest.
A 2025 study in PLOS One by researchers at Baylor College of Medicine’s Center for Medical Ethics and Health Policy did the first systematic count. Searching publicly available marketing between July and December 2023, they identified 298 organizations offering psychedelic retreats to English-speaking consumers, running 648 distinct retreat experiences across 440 physical locations, 130 of them inside the United States.
Nearly 84 percent of the organizations presented themselves as wellness businesses rather than religious or medical ones. Ayahuasca was the most commonly offered substance, at 73.8 percent. About a third offered more than one substance, which the authors flag as a safety concern because there is little research on mixing these drugs. Eight organizations did not disclose online what they were offering at all. Prices ran from $20 to $150,000.
This article gives no information about how any of these substances are used, prepared, dosed or obtained. What follows is about oversight and documented harm, because that is what a traveler can act on.
What the State Department says
The US Department of State addresses this directly on its country pages. On Peru, it states that “Facilities or groups offering ayahuasca/kambo are not regulated by the Peruvian government,” adding that they may not follow health and safety laws or practices. On Costa Rica, it says these substances are not regulated by the Costa Rican Ministry of Health, that wellness centers are often not verified, and that unverified alternative treatments have led to hospitalization.
The harms the Department documents most clearly are not deaths. For both countries it reports that US citizens have been sexually assaulted, injured or robbed while under the influence of these substances. That is two independent country pages describing the same pattern, though Costa Rica’s page puts it more strongly, naming serious injury rather than injury. The Peru page goes further about the wider industry, saying the tourism industry is not well regulated and that safety inspections for equipment and facilities are rare.
What the clinical literature documents
The largest dataset on adverse effects is the Global Ayahuasca Survey, published in 2022 in PLOS Global Public Health by José Carlos Bouso and colleagues. Among 8,216 participants answering the physical-effects questions, 69.9 percent reported at least one adverse physical effect on at least one occasion. Vomiting or nausea accounted for most of it, at 62 percent. Fainting was reported by 4.1 percent and fits or seizures by 1.3 percent. About 2.3 percent said a physical effect required medical attention.
On the mental health side, 55.4 percent of 7,839 respondents reported adverse effects in the weeks or months afterwards, and around 12 percent sought professional support. Notably, 87.6 percent of those reporting such effects considered them completely or somewhat part of a positive process of growth.
Two findings from that study matter most for a traveler. First, the authors write that adverse effects were significantly more common in non-supervised and non-traditional supervised settings, and less common in religious settings. Commercial retreats are not the low-risk end of that range. Second, the authors warn explicitly about seizure risk in people with a history of epilepsy or any brain disease.
The three sources on deaths, kept separate
These must not be collapsed into one claim, because they genuinely say different things.
Bouso and colleagues, citing prior literature, state that it has been impossible to directly relate a single death to ayahuasca use.
The State Department states that US citizens have suffered serious illness and, in some cases, died after taking these drugs.
A 2025 paper in the Journal of Analytical Toxicology by Jade Pullen and colleagues, working from the UK’s National Programme on Substance Use Mortality, found three previously reported fatalities involving DMT in the literature and added two UK cases. Their conclusion is specific: deaths from DMT are rare, no case with quantified post-mortem concentrations showed excess DMT, and every case involved other substances that contributed to death. Neither of the two new UK cases happened at a ceremony.
Read together, the shape is this. Deaths attributable to the brew by itself are not documented in the peer-reviewed record. Deaths involving these compounds combined with other drugs are. Governments report fatalities among their own citizens without publishing the toxicology. All three statements can be true at once.
The medical point that matters
The compounds involved interact with serotonergic prescription medicines, including common antidepressants. The Bouso paper names this risk; the Pullen paper’s second case involved prescribed antidepressants and a cause of death that included serotonin syndrome. This is a conversation for your own prescriber before you book anything, not a detail to research online. Article 677 covers medication and supplement interactions generally.
US law is also unambiguous. The Drug Enforcement Administration’s fact sheet states that DMT is controlled in Schedule I of the Controlled Substances Act, was placed there in 1971, and has no approved medical use in the United States. The Supreme Court’s 2006 decision in Gonzales v. O Centro Espírita Beneficente União do Vegetal carved out one narrow religious exemption for one organization under the Religious Freedom Restoration Act, subject to conditions. It is not a general legalization and it does not reach commercial retreats.
Does a wellness trip measurably improve your health?
The honest answer is that the research is positive, thin and old.
The main evidence is a 2018 systematic review in BMC Complementary and Alternative Medicine by Dhevaksha Naidoo, Adrian Schembri and Marc Cohen. It pooled 23 studies published between 1995 and 2017, covering 2,592 participants: eight randomized controlled trials, six non-randomized controlled trials and nine longitudinal cohort studies. Thirteen of the studies were conducted in the United States.
Every study reported a statistically significant improvement in at least one measured outcome at some point after the retreat. Some outcomes were objective: weight, abdominal girth, blood pressure, blood lipids, gene expression and telomere length.
Then come the caveats, which the reviewers state themselves. Most studies used small samples and quasi-experimental designs, described their methods poorly, collected little follow-up data and leaned on self-report questionnaires. The reviewers name a specific confounder: the vacation effect, where health improves simply from being removed from your normal routine. Five of the eight controlled trials compared the retreat against plain vacationers at the same property, which is the right design and the reason those studies deserve more weight.
Two gaps are worth saying out loud. No study reported any adverse effects, and the reviewers suggest that may reflect researchers not looking rather than nothing happening. And there is no published data on the economic impact of retreats at all.
On this library’s evidence tiers, that is preliminary research, not established evidence. It is also now nearly a decade old; the literature search ended in February 2017.
Five questions to ask before you pay a deposit
Written for this article, not borrowed from any source.
1. Who certified this property, and who accredited them? Ask for the certification body’s name and the certificate number, not the logo. If the answer is a standard-setter rather than an auditor, nobody inspected the property.
2. Can I read the criteria document? Public criteria are checkable. If the operator cannot point you to the document the property was measured against, the seal is decoration.
3. Which agency in this country licenses this facility? For a hotel, there is usually an answer. For plant-medicine retreats in Peru and Costa Rica, the State Department has already told you the answer is none.
4. What happens at 2 a.m. if something goes wrong? Get the distance in minutes to a licensed emergency medical facility. The State Department’s Peru page specifically advises travelers to ensure access to licensed emergency medical care.
5. What does my own clinician say about my prescriptions? Non-negotiable if you take an antidepressant or any other serotonergic medicine, have a seizure history or brain condition, or are traveling to address a diagnosed mental health condition.
When this belongs in front of a clinician
Three specific situations, not a generic disclaimer.
Before you go: if you take any serotonergic prescription medicine, have a history of seizures, epilepsy or any brain condition, or have uncontrolled high blood pressure or a heart condition, the plant-medicine question belongs with your prescriber rather than a retreat’s intake form.
While traveling: the State Department’s Peru page reports that US citizens have suffered serious complications or died while seeking medical care from non-traditional healers. The CDC’s Yellow Book is equally plain that CDC does not recommend traveling to other countries for untested medical interventions. If a treatment abroad is being offered as an alternative to care you would get at home, that is the moment to stop.
Afterward: in the Bouso survey, most participants reporting adverse mental health effects said they lasted under a week, and about 12 percent sought professional help. Effects that do not settle in that window, or that worsen, are a reason to call a clinician rather than wait them out.
The one thing to take away
A sustainability seal in travel tells you about a rulebook and sometimes about an auditing firm. It does not, by itself, tell you that anyone walked the property. The question that protects you is narrower and more awkward to ask: who inspected this, and can I read what they inspected it against?
For retreats selling plant medicine, there is a blunter version. Two US government country pages say the host government does not regulate these facilities. When the answer to “who licenses this” is nobody, every other assurance on the page is self-issued.
Keep exploring: climate change and health and gardening health benefits.
Sources
- Global Sustainable Tourism Council. “Global Sustainable Tourism Council home page (statement that GSTC does not directly certify products or services).” gstc.org
- Global Sustainable Tourism Council. “What is the difference between Certification, Accreditation, and Recognition?.” gstcouncil.org
- Global Sustainable Tourism Council. “GSTC Criteria Overview.” gstcouncil.org
- Global Sustainable Tourism Council. “GSTC Industry Criteria, Version 3, 21 December 2016 (PDF).” gstc.org
- ProPublica Nonprofit Explorer (IRS Form 990 data). “Global Sustainable Tourism Council, EIN 46-1050633, Washington, DC.” projects.propublica.org
- UN Environment Programme. “Making Tourism More Sustainable: A Guide for Policy Makers (2005), publication record.” unep.org
- UNEP and World Tourism Organization, 2005 (chapter copy hosted by the University of Florence). “Making Tourism More Sustainable: A Guide for Policy Makers, Chapter 1 (definition of sustainable tourism and the 12 Aims).” wwwlavoro.dsts.unifi.it
- World Tourism Organization and International Transport Forum, December 2019 (PDF hosted by the European Commission). “Transport-related CO2 Emissions of the Tourism Sector: Modelling Results.” transition-pathways.europa.eu
- World Tourism Organization (UNWTO, now UN Tourism). “Transport-related CO2 emissions from the tourism sector.” pre-www.unwto.org
- Nature Climate Change, 2018. “Lenzen M, Sun Y-Y, Faturay F, Ting Y-P, Geschke A, Malik A. "The carbon footprint of global tourism." Nature Climate Change 8:522-528. DOI: 10.1038/s41558-018-0141-x.” nature.com
- Tourism Management, 2015 (European Commission Joint Research Centre repository record). “Styles D, Schoenberger H, Galvez-Martos J-L. "Water management in the European hospitality sector: Best practice, performance benchmarks and improvement potential.".” publications.jrc.ec.europa.eu
- European Parliament, Policy Department for Structural and Cohesion Policies, October 2018 (copy hosted by the University of Brighton). “Peeters P, Gossling S, Klijs J, et al. "Research for TRAN Committee: Overtourism, impact and possible policy responses." PE 629.184.” researchdata.brighton.ac.uk
- World Tourism Organization, 2018. “'Overtourism'? Understanding and Managing Urban Tourism Growth beyond Perceptions, ISBN 978-92-844-1999-9 (publication record).” pre-www.untourism.int
- US Department of State, Bureau of Consular Affairs. “Peru International Travel Information (Travel Advisory reissued 16 May 2025; page last updated 15 May 2025).” travel.state.gov
- US Department of State, Bureau of Consular Affairs. “Costa Rica International Travel Information.” travel.state.gov
- US Drug Enforcement Administration, Diversion Control Division, December 2025. “Drug Fact Sheet: N,N-Dimethyltryptamine (DMT).” deadiversion.usdoj.gov
- Supreme Court of the United States, 21 February 2006 (slip opinion hosted by Cornell Legal Information Institute). “Gonzales v. O Centro Espirita Beneficente Uniao do Vegetal, No. 04-1084, 546 U.S. (2006), slip opinion.” law.cornell.edu
- PLOS One, 2025 (PubMed / PMC12047835). “Neitzke-Spruill L, Beit CS, Robinson JO, Singh N, Kambala S, Ramesh R, McGuire AL. "A landscape analysis of psychedelic retreat organizations advertising online." PLoS One 20(5):e0321648. DOI: 10.1371/journal.pone.0321648.” doi.org
- PLOS Global Public Health, 2022 (PubMed / PMC10021266). “Bouso JC, Andion O, Sarris JJ, Scheidegger M, Tofoli LF, Opaleye ES, Schubert V, Perkins D. "Adverse effects of ayahuasca: Results from the Global Ayahuasca Survey." PLOS Glob Public Health 2(11):e0000438. DOI: 10.1371/journal.pgph.0000438.” doi.org
- Journal of Analytical Toxicology, 2025 (PubMed / PMC12842604). “Pullen J, Moore R, Wood R, Rab E, Couchman L, Copeland CS. "Fatalities following DMT use: two case reports and a review of the literature." J Anal Toxicol 49(9):725-733. DOI: 10.1093/jat/bkaf064.” doi.org
- BMC Complementary and Alternative Medicine, 2018 (PubMed / PMC5761096). “Naidoo D, Schembri A, Cohen M. "The health impact of residential retreats: a systematic review." BMC Complement Altern Med 18(1):8. DOI: 10.1186/s12906-017-2078-4.” doi.org
- US Centers for Disease Control and Prevention, CDC Yellow Book (page dated 23 April 2025). “Complementary and Integrative Health Approaches to Travel Wellness.” cdc.gov