San Pedro and Depression: What We Know, What We Don’t

This article is intended for general information and does not provide medical advice or present Huachuma as a treatment for depression.

People sometimes contact us because they are living with depression and want to know whether Huachuma, also known as San Pedro, could help.

It is an understandable question, but I think it deserves a more careful answer than is often given. Depression can describe very different experiences, from persistent low mood and loss of interest through to severe illness that affects somebody's ability to function or leaves them feeling hopeless about the future. A retreat cannot treat all of those circumstances as though they are the same.

There is some early research exploring mescaline and mental health, and some people report positive changes following their experiences. At the same time, mescaline has not been established as a treatment for depression, and there are currently no controlled clinical trials demonstrating its effectiveness in people diagnosed with depressive disorders (Tabaac et al., 2026).

At The Huachuma Project, we therefore do not present Huachuma as a treatment for depression. When somebody living with depression approaches us, the more useful question is whether this particular kind of retreat is appropriate for them, at this point in their life, and what support already exists around them.

Depression Covers a Wide Range of Experiences

Depression is a recognised mental health condition, but the way it affects people varies considerably. It can involve persistent low mood, loss of interest or pleasure, low energy, difficulty concentrating, changes in sleep or appetite, feelings of guilt or worthlessness and, in more severe cases, thoughts of death or suicide (World Health Organization, 2026). Symptoms can also differ in their severity, duration and impact on everyday life.

For somebody with a history of depression who is considering a retreat, current circumstances are more useful than the diagnosis alone. A person whose symptoms are mild and well managed, with established support around them, presents a very different situation from somebody whose depression has recently worsened, is significantly affecting everyday life or includes thoughts of self-harm or suicide.

A Huachuma retreat can involve a long psychoactive experience, physical demands and emotions that may be difficult or unexpected. During screening, we therefore look at how the person is doing now, how stable things have been recently, what treatment or support they already have in place and what they are expecting from the retreat.

What the Research on Mescaline and Depression Tells Us

Research specifically examining mescaline and depression remains limited. One naturalistic study surveyed 452 adults about their most memorable mescaline experience. Among participants who reported a previous diagnosis of depression, anxiety, PTSD or substance-use disorders, many reported subjective improvements afterwards. These findings are interesting, but the study relied on retrospective self-reporting from people who had already chosen to use mescaline. There was no placebo group, no random assignment and no controlled treatment setting, so it cannot tell us whether mescaline caused those improvements (Agin-Liebes et al., 2021).

A systematic review published in 2026 examined the broader literature around mescaline and psychiatric conditions. Although some studies reported improvements in measures including depression and well-being, only a small proportion of the identified literature was considered suitable for analysis, and the authors concluded that the overall evidence was too limited and inconsistent for firm conclusions (Shaw et al., 2026).

A separate 2026 clinical review reached a similar conclusion: controlled trials involving mescaline in patient populations remain lacking, and much of the modern safety research has involved screened healthy volunteers (Tabaac et al., 2026).

The existing evidence is enough to justify further research, but not enough to establish San Pedro or mescaline as a treatment for depression.

For a broader discussion of what research currently tells us about mescaline, neuroplasticity and the nervous system, see our article Mescaline, the Nervous System and Feeling Safe: What We Know and What We Don’t.

A Change in Perspective Is Not the Same as Treating Depression

People sometimes describe feeling lighter, more connected or able to see parts of their life differently after a psychedelic experience. That can be important to them, but it does not tell us that the depression itself has been treated.

Someone may come away with a different perspective on a relationship, recognise a pattern they had not seen clearly before or reconnect with something they had lost touch with. They also return to the same life, with the same relationships, pressures, responsibilities and difficulties that were there before the retreat.

A powerful experience can feel very convincing in the moment, which is why I am cautious about attaching too much expectation to it. Feeling better during or immediately after a ceremony does not tell us how somebody will feel several weeks or months later, and it does not mean the underlying causes of their depression have been resolved.

I would much rather somebody approach Huachuma without expecting it to fix them or produce a particular outcome. That leaves more room for the experience to be what it is, without turning the medicine into something it cannot honestly promise to be.

What I Have Seen in Practice

I have worked with people who arrived carrying periods of low mood, disconnection, grief and difficult circumstances. Some have described changes afterwards that felt significant in how they viewed themselves or their lives, while others have had experiences that were far less clear. Some people have difficult days, some find themselves facing things they had avoided, and others experience something relatively subtle despite arriving with strong expectations about what the medicine might do.

There is no reliable way for me to predict how somebody will respond. I cannot tell someone in advance that Huachuma will improve their depression, and I would be uncomfortable claiming afterwards that the medicine had treated it because they felt better following a retreat. Too many other factors are involved in somebody’s life for that conclusion to be justified.

At The Huachuma Project, we do not claim to treat or cure depression, anxiety, trauma or any other mental health condition. Huachuma is not presented as a substitute for medical or psychological care, and we do not make promises about therapeutic outcomes.

What I can do is understand why somebody is considering the experience, what is happening in their life at the time, what support they already have and whether the retreat we offer appears appropriate for their circumstances.

Screening Matters

When somebody tells us they have depression, the conversation does not stop at the diagnosis. We need to understand what that currently means for them. How are they functioning day to day? How stable have things been recently? What support do they already have? Are they taking medication? Have there been recent changes in their mental health? What are they expecting the retreat to do?

These questions are not about excluding everybody who has experienced depression. They are about understanding the circumstances around the person.

There are also situations where a retreat is clearly not the right form of support. Someone experiencing an acute mental health crisis or immediate risk of suicide needs appropriate professional or emergency care, rather than attending a plant medicine retreat. Depression is associated with increased suicide risk, and effective psychological and medical treatments are available (World Health Organization, 2026).

Sometimes the responsible decision is to advise someone to seek other forms of support rather than attend a plant medicine retreat.

Medication Needs Its Own Conversation

Many people living with depression take antidepressants or other psychiatric medications. Medication should never be treated as something that simply needs to be stopped in order to attend a retreat. Decisions about changing or discontinuing prescribed medication belong between the person and the clinician responsible for their care.

Current medication is always taken seriously during our screening. We look at the medication itself, the reason it has been prescribed, how stable the person has been and whether there are any concerns around suitability or safety. Our approach is based on the individual circumstances. We would rather tell somebody that a retreat is not appropriate at that time than encourage them to alter or stop medication without the support of the doctor or clinician responsible for their care.

At THP, we do not position Huachuma as an alternative to conventional mental healthcare. Depression does not have one simple cause, and established treatments can include psychological therapy, medication or a combination of approaches depending on the person and the severity of their symptoms (World Health Organization, 2026).

If somebody is taking psychiatric medication, that needs to be discussed openly during screening so we can make a careful decision about whether the retreat is appropriate for them.

A Retreat Should Not Be the Only Source of Support

A retreat takes somebody out of their normal environment for a few days, but whatever was happening in their life before the retreat is usually still there when they return home. If depression has been affecting work, relationships, sleep, motivation or day-to-day functioning, those areas may still need attention afterwards.

For some people, existing therapy or other professional support can be useful for discussing what came up and placing the experience within the wider context of their life. Others may already have supportive relationships, routines or other forms of care in place.

I am particularly cautious when somebody approaches Huachuma as a final hope after everything else has failed. That puts a level of expectation on the retreat that neither the medicine nor the people facilitating it can honestly promise to meet. A retreat can become one part of a person's wider experience, but it should not be expected to carry the full weight of their mental health or replace the support they may still need afterwards.

So, Can San Pedro Help With Depression?

The accurate answer, without turning the question into a headline or a promise, is that we do not currently have enough evidence to say that San Pedro treats depression.

There is preliminary research worth following, and some people report improvements in mood, perspective and well-being after mescaline experiences. Those reports are relevant, but they do not establish that mescaline is an effective treatment for depression or allow us to predict how any individual person will respond.

Depression also varies considerably in severity, duration and circumstance. For somebody considering Huachuma while living with depression, the more useful questions concern how they are doing now, how stable things have been, what medication or support they have in place, what they are expecting from the retreat and whether the timing is appropriate.

At THP, that is where the conversation starts. We do not claim that Huachuma can cure depression, and we do not try to persuade somebody that a retreat is the answer to their mental health difficulties. We look at the person in front of us and decide, as carefully as we can, whether the retreat we offer is appropriate for their circumstances.

It may be less dramatic than the claims sometimes made around psychedelics and depression, but it is the answer the current evidence supports.

References

Agin-Liebes, G., Haas, T. F., Lancelotta, R., Uthaug, M. V., Ramaekers, J. G., & Davis, A. K. (2021). Naturalistic use of mescaline is associated with self-reported psychiatric improvements and enduring positive life changes. ACS Pharmacology & Translational Science, 4(2), 543–552. DOI: 10.1021/acsptsci.1c00018.

Shaw, J., Yong, A., Lee, J., Cheng, J., Andricioaei, A., Wang, J.-Y., Zisman-Ilani, Y., & Bota, R. (2026). The ethnopharmacological use of mescaline for psychiatric disorders: A systematic review. International Journal of Molecular Sciences, 27(7), 3081. DOI: 10.3390/ijms27073081.

Tabaac, B. J., Shinozuka, K., Fadel, M., Jones, G., Worchel, J., & Muir, O. S. (2026). Psychedelic therapy: A primer for primary care clinicians—Mescaline. American Journal of Therapeutics, 33(4), e318–e323. DOI: 10.1097/MJT.0000000000002160.

World Health Organization. (2026). Depressive disorder (depression). WHO Fact Sheet, updated 11 September 2026