The Bloom 186 - Slow October


The Bloom #186

Free Edition

micro effects

Last month was a decidedly slow month for psychedelic research. I only added seven studies to the database, and 'only' came across 140 studies (versus nearly 200 in the months before).

Still, there were interesting investigations of microdosing (null result), emotional reactivity (btter in psychonauts), a third generation psychedelic (GM-2505), set and setting (in cancer-related depression), brain plasticity (context dependent), endocannabinoid levels (after MDMA), and psilocybin for TRD (up to 20 weeks).

Floris - Founder of Blossom

ps Please join me today (11:00 AM MT / 1:00 PM ET / 10:00 AM PT) for the latest Delphi Insight Session. Lia Mix (Founder & CEO) will detail her own experience with ibogaine and present the launch of the Ibogaine Healthcare Policy Institute (IHPI).

pps Want to listen (or watch) to me discussing psychedelic research, then check out the latest podcast episode of The Psychedelic Paradigm Shift by Jeannie Page on YouTube or Spotify.

Latest Psychedelic Research

1 Cognitive and Subjective Effects of Psilocybin Microdosing: Results from Two Double-Blind Placebo-Controlled Longitudinal Trials

These two randomised, double-blind, placebo-controlled trials (n=141) conducted in semi-naturalistic settings found that microdosing psilocybin truffles did not significantly affect cognitive control, memory, social cognition, subjective well-being, attention, mood, or self-reported cognitive flexibility compared to placebo. Initial effects in some domains did not remain significant after correcting for multiple comparisons.

One truffle ceremony. Lasting transformation.

“It felt like a shared journey where you are not alone, which is essential for such a profound and transformational process.” - Nikki

A unique experience that leads to a richer life with a deeper sense of fulfilment and connection.

2 A novel psychedelic 5-HT2A receptor agonist GM-2505: The pharmacokinetic, safety, and pharmacodynamic profile from a randomized trial healthy volunteer

This Phase I single-ascending dose, randomised, placebo-controlled, double-blind study (n=48) found that GM-2505, a novel 5-HT2A receptor agonist, demonstrated an acceptable safety profile with mild transient adverse events at intravenous doses up to 20 mg, a half-life of 40-50 minutes, and dose-dependent effects on neuroendocrine hormones, neuropsychological measures, and resting-state electroencephalography similar to other 5-HT2A receptor agonists but with a duration of effects shorter than psilocybin and longer than DMT.

3 Set and setting in psilocybin-assisted therapy: A qualitative study of patients with cancer and depression

This qualitative study (n=28 interviews) of participants in a psilocybin-assisted therapy trial for cancer-related depression found that therapeutic benefits were closely tied to participants' ability to "surrender" (accepting and remaining open to the experience's intensity and unpredictability), with a safe, supportive, and ethical environment critical to fostering trust and engagement, and preparation and integration key to maximizing benefit, whilst music played a significant but variable role and ceremonial elements added meaning for many despite the clinical setting providing safety.

More Research

New on Blossom

1 Psychedelic Research Recap October

October 2025 was a calm month for psychedelic research. Whilst we saw record investments, there was a significant dip in research that was published. In our recap, we look back at an fMRI study on emotional reactivity in psychedelic users, another null result for microdosing for cognitive enhancement, and the importance of set and setting in psychedelic treatments.

Unlock 2250+ Psychedelic Research Summaries with a Pro Membership

"Blossom is my go-to resource for the latest in research" - Rick Strassman

Discover a treasure trove of knowledge and support the vital coverage & advancement of psychedelic research.

2 Psychedelic Research Links 2025

A comprehensive overview of all psychedelic research that has come out this year. We cover the research per month and provide a one-sentence summary for each new publication. After the full summary is added, a link to Blossom's review is added to the papers included in our database.

Spotlight

1 Microdosing Facilitator Program (Course)

The Microdosing Facilitator Program by our friends at Microdosing Institute is now open for applications.

This 8-month training is designed for those who feel called to guide others with microdosing in a safe, conscious, and effective way. The program combines science, practice, and deep personal development. You’ll also learn directly from masterclass facilitators, including James Fadiman, one of the leading researchers in microdosing, with whom they proudly collaborate.

“Among the more than 50 trainings of divergent qualities which have appeared the last few years in the psychedelic wellness and healing industry, this program is a haven of integrity and professionalism.”
— Donca Vianu, MD, Portugal – Psychiatrist, psychotherapist & former participant

Special for you: €100 discount on the program fee when you apply via me. Just make sure to select Blossom in the application form under “How did you hear about us?”

Molenvaart 76, Anna Paulowna, NH 1761AL
Unsubscribe · Preferences

Floris from Blossom

I write about the science and implementation of psychedelics as medicines. Join to learn alongside me and make the future happen sooner!

Read more from Floris from Blossom

The Bloom #185 Free Edition Lysene, not Lykos Next to research in clinical populations, the latest psychedelic research papers take a closer look at specific mechanisms and comparisons of similar compounds. We get a view into the differences between methamphetamine and MDMA, look at MDMA versus MDA (and their prodrugs), and look at fMRI data from a pharmuasca study (DMT + harmine). I cover lots more in the research recap for September. Floris - Founder of Blossom ps My friends at the...

The Bloom #184 Free Edition being the White Rabbit Normally, I would email you once every two weeks. But it's been nearly six weeks since the last Bloom. I'm fully caught up with the latest research (also see the recap for August), but because of family circumstances, the next edition might come in a bit later too. See some of the most interesting studies below, and the full updates on our papers page and link overview (for paid subscribers only). Floris - Founder of Blossom ps there are some...

The Bloom #183 Free Edition research abundance The summer is a time to take it a bit slower and let new ideas surface. Psychedelic researchers clearly didn't get that memo. Last month, 181 new papers were published and 18 (just like in June) new articles have been added to the database (full recap here). We take a look at control groups in psychedelic trials, MDMA for depression, ibogaine EEG data, and much more below. Floris - Founder of Blossom Latest Psychedelic Research 1 Control Group...