If you've been exploring the world of tryptamines, you've probably come across two names that look almost identical: 4-HO-MET and 4-PRO-MET. They're closely related compounds, increasingly discussed alongside more familiar psychedelics, and seriously confusing if you don't know the chemistry. This guide explains what they are, how they relate to psilocin (the active compound in magic mushrooms), what actually separates the two, and where they stand legally — clearly and honestly.
A quick note before we begin: this is an educational overview, not a usage guide. We won't be giving dosing instructions or how-to advice, because these are potent compounds and that's not what this article is for. What it will give you is an accurate, plain-language understanding of what these substances actually are.
The honest short version
4-HO-MET (also called metocin or methylcybin) is a synthetic tryptamine, a close chemical cousin of psilocin — the compound your body produces when you take magic mushrooms. 4-PRO-MET is a newer, more chemically stable “prodrug” version that converts the body into 4-HO-MET. Both are research compounds, both work on the same brain receptors as psilocin, and both sit in a genuinely complex legal gray area.
What Is 4-HO-MET?
4-HO-MET — full chemical name 4-hydroxy-N-methyl-N-ethyltryptamine, and also known as metocin or methylcybin — is a synthetic compound in the tryptamine family. It was first synthesized by the legendary American chemist Alexander Shulgin in the 1970s, and documented in his 1997 book TiHKAL (Tryptamines I Have Known and Loved). It started appearing as a research chemical in the late 2000s.
Structurally, 4-HO-MET is a very close analogue of psilocin — the compound that produces the effects of magic mushrooms. The two molecules share almost the same core structure, differing only in a small detail: where psilocin has two methyl groups attached to its nitrogen, 4-HO-MET swaps one of them for an ethyl group. That tiny change is the entire difference between a natural mushroom compound and this synthetic one.
Because it's so structurally similar to psilocin, 4-HO-MET acts on the same target in the brain: it's an agonist at the serotonin 5-HT2A receptor, the receptor responsible for the effects of classic serotonergic psychedelics. Users often describe its character as somewhat lighter and more recreational than psilocybin mushrooms, with a more stimulating rather than sedating quality — though as with all such compounds, individual experiences vary widely.
What Is 4-PRO-MET?
4-PRO-MET — full name 4-propionyloxy-N-methyl-N-ethyltryptamine — is the newer of the two compounds. It first appeared on the market around August or September 2025, making it a very recent arrival. The key thing to understand is that 4-PRO-MET is a prodrug of 4-HO-MET.
A prodrug is an inactive (or less active) compound that the body converts into the active one. This is exactly the same principle as the relationship between psilocybin and psilocin: when you take magic mushrooms, your body converts the psilocybin into active psilocin. In the same way, when 4-PRO-MET enters the body, enzymes cleave off the propionyl group, releasing the active compound — 4-HO-MET.
So in practical terms, 4-PRO-MET becomes 4-HO-MET in the body. The reason the prodrug version exists at all comes down to chemistry: the propionyl ester group makes 4-PRO-MET more chemically stable than the raw hydroxyl form. Research on analogous compounds suggests this kind of ester modification can improve shelf stability by roughly 40–60% at room temperature, which means a longer shelf life and more consistent material.
4-HO-MET vs 4-PRO-MET: The Key Differences
Since the two are so closely linked, here's what actually separates them in plain terms.
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Chemical relationship: 4-PRO-MET is a prodrug that converts into 4-HO-MET in the body. 4-HO-MET is the active compound; 4-PRO-MET is the precursor.
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Stability: 4-PRO-MET is the more chemically stable of the two, with a longer shelf life thanks to its ester group.
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Age on the market: 4-HO-MET has been around since the late 2000s. 4-PRO-MET only emerged in 2025, making it considerably newer and less studied.
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Reported character: Both are reported to share a similar overall profile, given that 4-PRO-MET converts into 4-HO-MET. Some anecdotal reports describe 4-PRO-MET as visually oriented and “lighter,” but reliable data is limited given how new it is.
How Do They Relate to Magic Mushrooms?
This is the most useful way to understand these compounds. Magic mushrooms contain psilocybin, which the body converts into psilocin — and psilocin is what produces the actual experience. 4-HO-MET is a synthetic molecule deliberately designed to be a close structural relative of psilocin.
Think of it this way: nature builds psilocin using a particular tryptamine skeleton. A chemist takes that same skeleton and makes one small modification, and the result is 4-HO-MET — recognisably related, acting on the same brain receptors, but a distinct, laboratory-made compound rather than something found in a mushroom.
If you're more interested in the natural side of this family, ours complete guide to magic truffles and our Golden Teacher mushroom guide cover the naturally-occurring compounds in depth.
Are 4-HO-MET and 4-PRO-MET Legal?
This is where things get really complicated, and where we'll be straight with you rather than give you a simple but misleading answer.
These compounds occupy what's often called a legal gray area. Because they're synthetic and relatively new, many countries haven't explicitly named them in their drug legislation — which is, in fact, part of why they were created. They're sometimes described as “legal by design,” meaning they were developed specifically to fall outside existing drug schedules. As an example, at the time of writing, 4-PRO-MET is not explicitly listed under Germany's New Psychoactive Substances Act (NpSG), and is not an explicitly controlled substance in the United States or Canada.
But — and this matters — “not explicitly listed” is not the same as “definitely legal.” Many countries have analogue laws or blanket new-psychoactive-substance laws that can cover compounds like these even without naming them specifically. The legal status also changes frequently as legislators catch up with newly-appearing substances. What's unlisted today can be scheduled tomorrow.
A note on safety Magic truffles aren't suitable for everyone. If you have a personal or family history of psychosis, schizophrenia, or bipolar disorder, or you take medications like SSRIs, MAOIs, lithium, or tramadol, you should not use psilocybin without consulting a qualified professional first. When in doubt, err on the side of caution.
A Note on Safety and Research
Because these are relatively new synthetic compounds, the body of scientific research on them is far smaller than for naturally-occurring psilocybin. Less is known about their long-term effects, their exact safety profile, and how they interact with other substances and medications. 4-PRO-MET in particular, having only emerged in 2025, has very little reliable data behind it.
This uncertainty is worth taking seriously. With well-studied compounds, there's decades of accumulated knowledge about risks and interactions. With novel research chemicals, that knowledge simply doesn't exist yet. Anyone exploring this space should treat the lack of data as a reason for genuine caution, not a green light.
As with all serotonergic compounds, combining these with medications such as SSRIs, MAOIs, lithium, or tramadol can be dangerous, and they are not suitable for anyone with a personal or family history of psychosis, schizophrenia, or bipolar disorder.
Frequently Asked Questions
What is the difference between 4-HO-MET and psilocin?
They're close structural analogues. Psilocin (the active compound in magic mushrooms) has two methyl groups on its nitrogen; 4-HO-MET swaps one for an ethyl group. Both act on the same 5-HT2A serotonin receptor, but 4-HO-MET is synthetic while psilocin is produced naturally by the body from psilocybin.
Is 4-PRO-MET stronger than 4-HO-MET?
4-PRO-MET converts into 4-HO-MET in the body, so they share the same active compound. The main practical difference is chemical stability and shelf life, not a fundamentally different effect. Reliable comparative data is limited because 4-PRO-MET is very new.
Is 4-HO-MET natural like magic mushrooms?
No. 4-HO-MET is a synthetic compound, first made in a laboratory by Alexander Shulgin. It's chemically related to the natural compound psilocin, but it does not occur in mushrooms or any other natural source.
Are these compounds legal in Europe?
It varies by country and changes frequently. Some countries have not explicitly listed them, but analogy and new-psychoactive-substance laws may still apply. Always verify your local laws before considering a purchase. This is not legal advice.
Are 4-HO-MET and 4-PRO-MET well researched?
No — far less than natural psilocybin. 4-HO-MET has limited data and 4-PRO-MET, which emerged in 2025, has very little. This lack of research is a genuine reason for caution.
The Honest Bottom Line
4-HO-MET and 4-PRO-MET are two closely-related synthetic tryptamines that sit alongside, but are distinct from, the naturally-occurring compounds in magic mushrooms and truffles. 4-HO-MET is the established active compound; 4-PRO-MET is its newer, more stable prodrug. Both work on the same brain receptors as psilocin, both occupy a shifting legal gray area, and both are far less studied than their natural counterparts.
If you're drawn to the better-understood, naturally-occurring side of this world, that's where our focus has always been. Explore our magic truffles and grow kits — natural, legal under Dutch law, and backed by decades of accumulated knowledge.
Disclaimer
This article is for informational and educational purposes only. It is not medical or legal advice, nor a usage guide. These compounds are research chemicals with limited safety data. The legal status of psychoactive substances varies by country and changes frequently; readers are solely responsible for verifying the laws that apply to them. Intended for adults (18+). Always prioritize safety and the law.
